tag:blogger.com,1999:blog-49596924166502498722024-03-13T13:00:07.067-07:00PaleometallurgyExperiments in early metallurgyJeffEvartshttp://www.blogger.com/profile/01110136459320492803noreply@blogger.comBlogger29125tag:blogger.com,1999:blog-4959692416650249872.post-6337945740774645162016-06-25T17:15:00.000-07:002016-06-25T17:15:35.524-07:00SCA 50 Bloomery Smelt a la Wareham ForgeIt was my great good fortune to attend the <a href="http://www.sca50year.org/">SCA 50 year</a> celebration, and while I was there I spent a fair amount of time hanging out (and occasionally helping out) at the "Bloomery Iron Smelt" experiment that <a href="http://www.warehamforge.ca/">Darrell Markewitz</a> ran.<br />
<br />
It was the first time I'd ever actually been at the forge when the bloom was extracted, and I have to say I was pretty overwhelmed. I had to leave early Wednesday morning, so I'm not sure how the into-the-night reheat or next-morning compaction went, but I was glad to be there nonetheless.<br />
<br />
Here's a short video showing some of what we did:<br />
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<iframe allowfullscreen="" class="YOUTUBE-iframe-video" data-thumbnail-src="https://i.ytimg.com/vi/2qKYLaOsfuU/0.jpg" frameborder="0" height="266" src="https://www.youtube.com/embed/2qKYLaOsfuU?feature=player_embedded" width="320"></iframe></div>
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Hope you enjoy.JeffEvartshttp://www.blogger.com/profile/01110136459320492803noreply@blogger.com1tag:blogger.com,1999:blog-4959692416650249872.post-7569317069471174012015-03-11T09:29:00.001-07:002015-03-12T09:07:30.052-07:00Upcoming events Spring/Summer 2015It's been a busy six months, mostly working on chemistry rather than metallurgy, but metallurgy season is coming around, so here are some upcoming events you might want to check out:<br />
<br />
Events in 2015 <br />
<br />
<a href="http://warehamforgeblog.blogspot.ca/2015/03/early-iron-4-event-details.html">Early Iron IV</a><br />
When: April 24-26<br />
Where: Ashokan Center, Olivebridge NY, USA<br />
<br />
<a href="http://www.warehamforge.ca/TRAINING/smeltcourse/index.html">Iron Smelting Course</a><br />
When: May 24-26<br />
Where: Proton, CA<br />
<br />
<a href="http://www.fingerbuster.com/">Prehistoric Metallurgy Class</a><br />
When: July 3-6, Butser Ancient Farm<br />
Where: <a href="http://www.butserancientfarm.co.uk/">Butser Ancient Farm</a>, Chalton, UK<br />
<br />
<a href="http://www.umha-aois.com/">UMHA AOIS (BRONZE AGE)</a><br />
When: Late July, Early August <br />
Where: Skibereen Co Cork, IEJeffEvartshttp://www.blogger.com/profile/01110136459320492803noreply@blogger.com0tag:blogger.com,1999:blog-4959692416650249872.post-67376816779876031452014-07-25T17:12:00.000-07:002014-07-25T17:12:40.986-07:00Assaying galena for silver<blockquote class="tr_bq">
<i>In which I create large quantities of a small molecule with unforgettable properties while simultaneously inventing a new Olympic Sport.</i></blockquote>
<br />
I was recently exchanging email with Fergus Milton (a most excellent Brit who teaches a class on copper smelting at <a href="http://www.butserancientfarm.co.uk/">Butser Ancient Farm</a>) on the possibility of adding a unit on <a href="https://en.wikipedia.org/wiki/Cupellation">cupellation</a> to the class. This jogged a memory and I recalled that I had purchased a quantity of galena some time ago. I hadn't had any particular drive to smelt lead, but now that I might get lead <i>and</i> silver out of the effort, I was moved to retrieve it.<br />
<br />
The galena was in my Ore Storage Facility, known to the less appreciative as "that big dusty pile of rocks and bags of yet more rocks you keep behind the bar". After a time I had moved enough of the contents of the OSF to identify the <i>correct</i> unlabelled tan canvas sack which contained my galena. I towed it over to the scale and learned that I had almost exactly 7.5 kilos of the stuff.<br />
<br />
Now we all know that some galena is argentiferous and some is not. Having been (to date) unsuccessful in coming up with a decent excuse to blow the cash for an X-Ray Fluorescence analyzer, I was seemingly left with two alternatives: Send the sample off to a lab to have it analyzed, or do a smelt & cupel, trusting that I'd get it all right the first time, and find the silver if there was any. Neither appealed.<br />
<br />
Then I had a thought. (This happens more often than I like.)<br />
<br />
Like any aspiring mineralogist, I have some hydrochloric acid for identifying metals in rocks. Lead chloride is soluble. Silver chloride is not. It should be a simple matter of dissolving the galena in hydrochloric acid and watching for an insoluble precipitate. Silver chloride has some well-defined characteristics, so it should be easy enough to confirm the silver and estimate the silver content of the original lead.<br />
<br />
Being a Man Of Action, I grabbed the jug of acid and a handful of galena and headed to the kitchen. I tossed the galena in a glass pie pan and promptly poured some acid over it.<br />
<br />
I can<i> <b>hear</b></i> the chemists in the crowd wincing.<br />
<br />
Now the chemistry I had concerned myself with was fairly straightforward:<br />
<br />
PbS + Ag<sub>2</sub>S + 4HCl = PbCl<sub>2</sub>(aq) + 2AgCl(s)<br />
<br />
But this is <i>not</i> a balanced equation, since it doesn't account for the hydrogen or sulfur on the left hand side. A correct and balanced equation looks like this, with aqueous, solid, <i>and</i> gaseous products:<br />
<br />
PbS + Ag<sub>2</sub>S + 4HCl = PbCl<sub>2</sub>(aq) + 2AgCl(s) + 2H<sub>2</sub>S(g)<br />
<br />
Anyone remember <a href="https://en.wikipedia.org/wiki/Hydrogen_sulfide">hydrogen sulfide</a>? The more enterprising among you may have produced it in stink bombs when you were kids. It has an eye-watering odor of rotting meat crossed with severe flatulence. It's also flammable and quite toxic, but I can personally assure you it's the odor that will speed your pace when clearing the area. <br />
<br />
Flash forward in time five minutes. Every window in the house, as well as the front and back doors, are wedged fully open. Every fan in the kitchen, lavatories, and HVAC system is on "high". The pie pan has been transferred to the backyard.<br />
<br />
Ever try to run through your living room while squinting and holding your breath? While carrying a pie pan full of corrosive liquid which is actively producing toxic gas? Getting the sliding glass door to the backyard open under these conditions yields a difficulty rating of 6.0. I believe I have a new Olympic Sport in the offing.<br />
<br />
Happily hydrogen sulfide is a small and (mostly) hydrophobic molecule, so once it's cleared, it's cleared. It doesn't linger. At that point it's only a problem for the people downwind of you.<br />
<br />
The adventure over, I was able to discern that my galena <i>does</i> in fact contain silver. Stay tuned for an account of smelting lead and cupellation of silver.<br />
<br />
<hr />
<span style="font-size: x-small;"><i><br /></i></span>
<br />
<blockquote class="tr_bq">
<span style="font-size: x-small;"><i>Postscript:</i></span> </blockquote>
<blockquote class="tr_bq">
<span style="font-size: x-small;"><i> </i></span><span style="font-size: x-small;"><i><span style="font-size: x-small;"><i> <span style="color: red;">DANGER: Usually in metallurgy the worst thing that could happen to you is a disfiguring burn. This is different. <u>Every one</u> of the reactants and byproducts of this reaction are toxic to humans. Don't even start this unless you know how to handle and dispose of them safely.</span></i></span></i></span> </blockquote>
<blockquote class="tr_bq">
<span style="font-size: x-small;"><i><span style="font-size: x-small;"><i>F</i></span>or those qualified to do this properly, the stochiochemistry follows: Galena (lead sulfide) has a molecular weight of 239. Lead chloride has a molecular mass of 278 and a solubility of 10g/L in water. The acid I used is 31.45%, 20° Baume, or 8.5molar hydrochloric acid.</i></span> </blockquote>
<blockquote class="tr_bq">
<span style="font-size: x-small;"><i>Scaling everything for 0.036 moles, we get the following values: 8.6g of lead sulfide + 4.3cc of 8.5M hydrochloric acid + 995.7cc of distilled water results in 10g of lead chloride dissolved in 1L of water. Excess acid and/or water will assure only the silver precipitates.</i></span></blockquote>
JeffEvartshttp://www.blogger.com/profile/01110136459320492803noreply@blogger.com0tag:blogger.com,1999:blog-4959692416650249872.post-2004663167304933212014-02-20T10:32:00.000-08:002014-02-20T10:32:01.311-08:00Not dead or dyingDespite the dearth of posts in 2014, this blog is not dead. I've just been involved with experiments involved in other disciplines. (See my paleotechnology and paleochemistry blogs via the links above for more info)JeffEvartshttp://www.blogger.com/profile/01110136459320492803noreply@blogger.com0tag:blogger.com,1999:blog-4959692416650249872.post-57673732334325342142013-06-30T02:08:00.001-07:002015-01-17T19:16:22.813-08:00Bronze age bellows a la Brenda CraddockBrenda Craddock taught an excellent unit on making primitive bellows on the second day of the Butser archaeometallurgy course, and this is an attempt to capture some of that excellent teaching.<br />
<br />
The bellows pattern used was referred to locally as a "Roman Kite Bellows", although I've been unable to find that term used elsewhere. Brenda confirmed that "No one actually knows what bronze age bellows looked like.", but her design is intentionally "As simple as possible" and based on "later descriptions and depictions" of them.<br />
<br />
The bill of materials is relatively short:<br />
<ol>
<li>one large tanned goat skin</li>
<li>one hollow nozzle (we used a segment of bamboo)</li>
<li>two short, smooth, regular, handles (dowels work)</li>
<li>leather awl with thread</li>
<li>a few feet of rough twine</li>
<li>(optional) gelatin glue </li>
</ol>
The bellows pattern (figure 1 below) itself was designed to fit into an animal skin with maximum utility, with the narrow bit to the left terminating at the scruff of the neck, and the rounded section on the right straddling the tail and haunch. The rest is made as broad as the hide will allow. Caveat: I was unable to trace her pattern directly, so this is a projection from some images captured during the class.<br />
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<a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjo6cyvUYnJLcF-C708ATJGkPDO-Rl9lbohkABGW-252bUblNAdGyGO73-tC5EB4Hs1H4Pzrv_udhyphenhyphenOU_p7g_7dtxInq1rT0wrfaQhOVUGSt0BlRWAR8TtfnpmAxiuh0s8CBACOl8t-5Xyo/s756/RawPattern.png" imageanchor="1" style="margin-left: 1em; margin-right: 1em;"><img border="0" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjo6cyvUYnJLcF-C708ATJGkPDO-Rl9lbohkABGW-252bUblNAdGyGO73-tC5EB4Hs1H4Pzrv_udhyphenhyphenOU_p7g_7dtxInq1rT0wrfaQhOVUGSt0BlRWAR8TtfnpmAxiuh0s8CBACOl8t-5Xyo/s320/RawPattern.png" height="255" width="320" /></a></div>
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<h3>
Production</h3>
<br />
<h4>
General notes</h4>
<ul>
<li>The bellows are produced such that the handles have the rough/suede side of the hide on their outside, so that they seal suede-against-suede rather than smooth-to-smooth. This gives a better seal, which is essential.</li>
<li>The bellows can be fashioned such that the seams are on either side, although in this class all the bellows we produced had the seams on the outside.</li>
</ul>
<h4>
The foot</h4>
See figure 2a. The hide is bent slightly along the A-B line, then points C and E are brought together. The edges A-C and A-E are sewn together starting from point C/E and progressing toward A, so as to avoid any misalignment. Then points D and E are brought together, and sewn as above, from the point D/E toward B. Lastly, a small triangular gusset is sewn into the V formed by the edges CF and DG. The result should look something like figure 2b.<br />
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<table align="center" cellpadding="0" cellspacing="0" class="tr-caption-container" style="margin-left: auto; margin-right: auto; text-align: center;"><tbody>
<tr><td style="text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgHLWRTleVBSbSrzMz0KJhguQfORUxS2tW-w6_XpieAm63sLTZEI_xBnx5EKsUUA3rudJt8DyoMJhj7hcqehYV3FqAPm9o39NQ8EhWN0MZPf4cf71UQMqbzK9Q6IWU-6KYpF-EePVi-8hCk/s640/FootFigA.png" imageanchor="1" style="margin-left: auto; margin-right: auto;"><img border="0" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgHLWRTleVBSbSrzMz0KJhguQfORUxS2tW-w6_XpieAm63sLTZEI_xBnx5EKsUUA3rudJt8DyoMJhj7hcqehYV3FqAPm9o39NQ8EhWN0MZPf4cf71UQMqbzK9Q6IWU-6KYpF-EePVi-8hCk/s320/FootFigA.png" height="240" width="320" /></a></td><td style="text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjjxdDgWU7n5u-i2Ydzs8_yV0zEecn5P0tB5-HJgm9QG954Db1t0B6TAtsPJe5CLAwy7D2UXUuveEwPr4w1flEQs_8Wry53asidgNuyULW6bMknVo1vqX3EyS6ICScLUzmw6mRVD4e-eNPI/s640/MOV0032.MOD.jpg" imageanchor="1" style="margin-left: auto; margin-right: auto;"><img border="0" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjjxdDgWU7n5u-i2Ydzs8_yV0zEecn5P0tB5-HJgm9QG954Db1t0B6TAtsPJe5CLAwy7D2UXUuveEwPr4w1flEQs_8Wry53asidgNuyULW6bMknVo1vqX3EyS6ICScLUzmw6mRVD4e-eNPI/s320/MOV0032.MOD.jpg" height="240" width="320" /></a></td></tr>
<tr>
<td class="tr-caption" style="text-align: center;">Fig 2a</td>
<td class="tr-caption" style="text-align: center;">Fig 2b</td></tr>
</tbody></table>
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<h4>
</h4>
<h4>
The snout</h4>
See figure 3a. The hide is curled around the A-B line, joining point C with E and D (roughly) with F. Sewing proceeds from point C/E toward point D/F, so that the joint at the handle tabs is clean and any discrepancies occur at the snout. Figure 3b shows the curl and the point from which to sew.<br />
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<table align="center" cellpadding="0" cellspacing="0" class="tr-caption-container" style="margin-left: auto; margin-right: auto; text-align: center;"><tbody>
<tr><td style="text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEg0RVyFiDEoVtwGHvfM3Q4Xga2wMI5cpG6r1iJDQu-RA9VavoT5WospYDNxIZxKdtkG36DgZiut15HltPhgFGsHXflKEOXMkXlzyXM31x7ZeH_qsg1bKwzDf_y1sSM51SJcL7bUpRV83INU/s640/SnoutFigA.png" imageanchor="1" style="margin-left: 1em; margin-right: 1em;"><img border="0" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEg0RVyFiDEoVtwGHvfM3Q4Xga2wMI5cpG6r1iJDQu-RA9VavoT5WospYDNxIZxKdtkG36DgZiut15HltPhgFGsHXflKEOXMkXlzyXM31x7ZeH_qsg1bKwzDf_y1sSM51SJcL7bUpRV83INU/s320/SnoutFigA.png" height="240" width="320" /></a></td><td style="text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjCjtb07yB7K4eTXLq8qPHTld5MAvBX68CH3H5CWQ6t3CbSur_h5VKU3LNxTqnbSvk2cWQinyt3IUOBDxglgeVQu9wwOrNEGoq99YygCarBkq7XCwCwIZyzW2fUf-ObDQxPe98wreGaeXHm/s640/MOV0035.MOD.jpg" imageanchor="1" style="margin-left: 1em; margin-right: 1em;"><img border="0" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjCjtb07yB7K4eTXLq8qPHTld5MAvBX68CH3H5CWQ6t3CbSur_h5VKU3LNxTqnbSvk2cWQinyt3IUOBDxglgeVQu9wwOrNEGoq99YygCarBkq7XCwCwIZyzW2fUf-ObDQxPe98wreGaeXHm/s320/MOV0035.MOD.jpg" height="240" width="320" /></a></td></tr>
<tr>
<td class="tr-caption" style="text-align: center;">Fig 3a</td>
<td class="tr-caption" style="text-align: center;">Fig 3b</td></tr>
</tbody></table>
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<h4>
</h4>
<h4>
The handles</h4>
As we mentioned before, the hide is wound around the handles such that the rough side is on the outside to provide the best possible seal when used. Once the handle sleeves have been sewn, the handles are inserted most of the way into them, and the bottom of both sleeves are pinched together and sewn flat to prevent air from escaping from the joint. Figure 3b above shows the measuring for this process. Figure 4 shows the bellows at this stage.<br />
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<tr><td style="text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEh6wcXLsA6AaDxPewN_brhhiO3jeWIn2C5BcqNbrcvkJ1W3aq7ShJo544gGQ5Y52wczSrhNplvQ6T3izbzeSFXaYqmZjUPQ3ASU4VMfLyHbRxkH-Hyy49Zb-IEc0l64GNy9MLCd-fVn4a7x/s1280/MOV0036.MOD.jpg" imageanchor="1" style="margin-left: auto; margin-right: auto;"><img border="0" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEh6wcXLsA6AaDxPewN_brhhiO3jeWIn2C5BcqNbrcvkJ1W3aq7ShJo544gGQ5Y52wczSrhNplvQ6T3izbzeSFXaYqmZjUPQ3ASU4VMfLyHbRxkH-Hyy49Zb-IEc0l64GNy9MLCd-fVn4a7x/s320/MOV0036.MOD.jpg" height="256" width="320" /></a></td></tr>
<tr><td class="tr-caption" style="text-align: center;">Fig 4</td></tr>
</tbody></table>
<h4>
</h4>
<h4>
The vent</h4>
The hollow vent for the bellows is placed in the "snout" of the hide we have sewn. It may be liberally coated with gelatin glue, as may the inside of the snout. Then a meter of twine is wound about the joint between the two. The twine is laid so that its midpoint is beneath the snout/vent joint (see Fig 5a), then wound from both sides. It is single-knotted at least every other winding to prevent slippage, then tied securely when the ends are reached. Fig 5b shows the completed tie. Note that there is considerable linear coverage along the joint.<br />
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<td style="text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjFlordQSplyrMsLYSZ5xUBju1uE4EEC1KW6HGymoCr9oNUsyI5dmnDoHyfdEu2UxVoVY9xcfCxHsDB1RoTfgFbOuOhe3tnrND_iLGf6Fv3GqsL-HdCft_HY_fQwSt7nETjD4bNum7LXtbt/s640/MOV0037.MOD.jpg" imageanchor="1" style="margin-left: auto; margin-right: auto;">
<img border="0" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjFlordQSplyrMsLYSZ5xUBju1uE4EEC1KW6HGymoCr9oNUsyI5dmnDoHyfdEu2UxVoVY9xcfCxHsDB1RoTfgFbOuOhe3tnrND_iLGf6Fv3GqsL-HdCft_HY_fQwSt7nETjD4bNum7LXtbt/s320/MOV0037.MOD.jpg" height="240" width="320" />
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<td style="text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhEHyfrO6Y2zRhMfHC4r0-KxLZUcCcu5s8VriUZtXMTISWQYeQaw5ZPzjZRfW13AJArkyaVmA_mf8e69BYb8vPE-dJY-kYRCvPff5x18ocGb6qBBDPKoqNhpUAxl-frCEH7vxDJlh-8l3e0/s1280/Snip.dvd.jpg" imageanchor="1" style="margin-left: 1em; margin-right: 1em;"><img border="0" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhEHyfrO6Y2zRhMfHC4r0-KxLZUcCcu5s8VriUZtXMTISWQYeQaw5ZPzjZRfW13AJArkyaVmA_mf8e69BYb8vPE-dJY-kYRCvPff5x18ocGb6qBBDPKoqNhpUAxl-frCEH7vxDJlh-8l3e0/s320/Snip.dvd.jpg" height="256" width="320" /></a></td></tr>
<tr>
<td class="tr-caption" style="text-align: center;">Fig 5a</td>
<td class="tr-caption" style="text-align: center;">Fig 5b</td></tr>
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<h3>
</h3>
<h3>
Usage</h3>
Here is Ryan Watts, a classmate, using the constructed bellows:<br />
<br />
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<iframe allowfullscreen='allowfullscreen' webkitallowfullscreen='webkitallowfullscreen' mozallowfullscreen='mozallowfullscreen' width='320' height='266' src='https://www.blogger.com/video.g?token=AD6v5dxUFFiQMU5FlfBwnSiHmXBCQ_3atiYuvsj89mmdzSHFLGwaLEvsjqVYGInw7qCtFhh80raa2lW_5W7LqqiSjg' class='b-hbp-video b-uploaded' frameborder='0'></iframe></div>
<br />
<h4>
Airflow</h4>
We measured the approximate air displacement of a single push of the bellows and arrived at a volume of 1.4 liters. With an average of 1.25 pushes per second over an hour long session, we get an airflow of 105L/min. Vigorous pumping increases the pushes per minute but usually decreases the volume per push somewhat. It would be extremely difficult for someone to sustain over 200L/min for an hour.<br />
<br />
<h2>
Conclusions</h2>
<ul>
<li>The airflow is easily sufficient for artisinal production of gold,
silver, lead, mercury, copper, and tin. It is doubtful whether a single
bellows of this type would be sufficient to smelt iron.</li>
<li>Given a good leather awl and all the materials required, a bellows of this type could probably be constructed by an experienced craftsman in less than two hours.</li>
<li>The materials required could largely be taken from a single animal (Brain-tanned hide, gut/sinew thread and twine, bone nozzle)</li>
<li>Considering the number of materials, parts, and processes required to make them, a bellows might be among the most complicated tools on a bronze age farmstead.</li>
</ul>
Unknownnoreply@blogger.com1tag:blogger.com,1999:blog-4959692416650249872.post-24801471839660756522013-03-29T12:35:00.000-07:002013-04-23T09:57:07.215-07:00Upcoming eventsMay 24-26: Ontario, Canada<br />Darrell Markewitz, author of <a href="http://warehamforgeblog.blogspot.com/">Hammered Out Bits</a>, is teaching an <a href="http://warehamforgeblog.blogspot.com/2013/03/students-for-iron-smelting.html">iron smelting</a> class, where I hope to smelt my first iron ore. <br /><br />May 31-Jun 3: Hampshire, UK<br />Fergus Milton at <a href="http://www.butserancientfarm.co.uk/">Butser Ancient Farm</a> is teaching a four day <a href="http://www.fingerbuster.com/">archaeometallurgy class</a> covering copper and bronze smelting. I hope to walk away with a cast axe head.<br /><br />Jun 14-16: London, UK<br />The <a href="http://hist-met.org/">Historical Metallurgy Society</a> is having their <a href="http://hist-met.org/agm2013.html">50th anniversary conference</a>. I have just paid my membership and registration fee so that I may attend.<br /><br />I also plan to visit Malta and Morocco, so if anyone knows of any events related to early mining or metallurgy in or around those places, please let me know!Unknownnoreply@blogger.com0tag:blogger.com,1999:blog-4959692416650249872.post-44258530454382429452013-01-09T13:01:00.000-08:002013-04-23T09:57:07.223-07:00Success, sort of.A second three hour high-heat smelting reduced the contents of both crucibles completely. The copper came out as a single large button. The tin was different. There was one small button (5g) and a three layer "cake" of slag... a light grey very granular layer was the bulk of it. Atop that was a dark grey layer and atop that were little balls of tin, like a froth, embedded in the borax.<br /><br /><div class="separator" style="clear: both; text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgcm9E0UXegNLh6V6gVh0fBMMa8S6q4x3n3DQbGJYZq1JLuw6HCwJmznakixTZHVXCyB6o45qBwYfV4cmwuum5il6Wv_BuB6Ecr6AyhSDtkxahmjVmVxVQHHGgyUePl0QrQx3JzhTETZ1Q/s1600/Layers1.png" imageanchor="1" style="margin-left: 1em; margin-right: 1em;"><img border="0" height="309" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgcm9E0UXegNLh6V6gVh0fBMMa8S6q4x3n3DQbGJYZq1JLuw6HCwJmznakixTZHVXCyB6o45qBwYfV4cmwuum5il6Wv_BuB6Ecr6AyhSDtkxahmjVmVxVQHHGgyUePl0QrQx3JzhTETZ1Q/s320/Layers1.png" width="320" /></a></div><br /><br /><br /><br /><br /><div class="separator" style="clear: both; text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjpm3jC7sRa2fqvPbI2Th6nxkqsdZkaB2OxYnsIHuIijP7qciEaISOJnmp5JsZQEHDZAQGspxAHHLS_5JykytnIMgjUheyWt7wFYVPXQr_NvjuHrgTMKlXqRP1B6x-kwTjg6U27cl37-S8/s1600/Layers2.png" imageanchor="1" style="margin-left: 1em; margin-right: 1em;"><img border="0" height="281" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjpm3jC7sRa2fqvPbI2Th6nxkqsdZkaB2OxYnsIHuIijP7qciEaISOJnmp5JsZQEHDZAQGspxAHHLS_5JykytnIMgjUheyWt7wFYVPXQr_NvjuHrgTMKlXqRP1B6x-kwTjg6U27cl37-S8/s320/Layers2.png" width="320" /></a></div><br /><br /><br />In researching the tin, I find that tin forms a significant amount of tin silicate slag, given the chance. Historically quicklime was added to displace the tin from the silicon. I will try that next time. 40% of the mass of the cassiterite in quicklime is the proportion recommended.Unknownnoreply@blogger.com0tag:blogger.com,1999:blog-4959692416650249872.post-10440359034335650412013-01-05T23:27:00.000-08:002013-04-23T09:57:07.229-07:002013 begins: Smelting in a kilnI got a Cress kiln a while back. I refitted it with a (much, much) longer cord, and here's what it looks like now:<br /><br /><div class="separator" style="clear: both; text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEj-ntAV6qr2k338PLVgbuG5RP0UXq95Q6yFDh2erdPMq8TwM_1OPd6e84NtR_J-2qy94uyllwsJW2lcLTvS2vZjXDDfhiwpnMhzjId0bMAl4Tzb-Kk-ggToBKlMnleXDA_H5hhcG-TtOPs/s1600/Cress.png" imageanchor="1" style="margin-left: 1em; margin-right: 1em;"><img border="0" height="320" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEj-ntAV6qr2k338PLVgbuG5RP0UXq95Q6yFDh2erdPMq8TwM_1OPd6e84NtR_J-2qy94uyllwsJW2lcLTvS2vZjXDDfhiwpnMhzjId0bMAl4Tzb-Kk-ggToBKlMnleXDA_H5hhcG-TtOPs/s320/Cress.png" width="240" /></a></div><div style="text-align: center;"><br /></div><span style="font-family: Arial,Helvetica,sans-serif;">I tried smelting copper and tin in it today, using crushed charcoal as a reducing agent and borax as a flux and sealant.</span><br /><br />Crucible 1:<br /><blockquote class="tr_bq"><span style="font-family: "Courier New",Courier,monospace;">100g cassiterite</span><br /><span style="font-family: "Courier New",Courier,monospace;"> 10g powdered charcoal</span><br /><span style="font-family: "Courier New",Courier,monospace;"> 5g borax</span></blockquote>Crucible 2:<br /><blockquote class="tr_bq"><span style="font-family: "Courier New",Courier,monospace;"> 70g malachite</span><br /><span style="font-family: "Courier New",Courier,monospace;"> 10g powdered charcoal</span><br /><span style="font-family: "Courier New",Courier,monospace;"> 5g borax</span></blockquote>Both crucibles were covered by ceramic discs that fit loosely.<br /><br />I heated the kiln on "low" for about 30 minutes, "medium" for about 30 minutes, and "high" (dark orange heat) for 2 hours, then reversed the process for cooldown, for a total of about a 4 hour total firing. When I pulled them out, imagine my surprise finding only partially decomposed ore, and plenty of charcoal left. The copper was considerably further along than the tin in terms of decomposition, but neither had a substantial lode of purified metal.<br /><br />Tomorrow, I shall extend the time for full heat from 2h to 3h and see what's what.<br /><br />Unknownnoreply@blogger.com0tag:blogger.com,1999:blog-4959692416650249872.post-84665558708052081442012-05-23T03:14:00.000-07:002013-07-05T12:20:27.072-07:00A new quest: Bellows without tanned leatherIn a moment of idle curiosity, I wondered whether you could make a practical (historic) bellows without tanned leather or woven cloth. It occurred to me that perhaps you could use something already flexible that did not need not some days-long chemically complex tanning process nor a tight warp loom to produce.<br /><br />How about an animal bladder? I know they were used for two purposes in-period: as a bag for light items by the first peoples of North America, and as a balloon by dark ages Europeans. Are they large enough? Robust enough? Anyone ever heard of a bladder-based bellows?<br /><br />Any other ideas are welcome: any animal, vegetable, or mineral alternative to tanned leather and cloth is a possibility.<br /><br />Period references are of course extremely welcome. Please! Inform me!Unknownnoreply@blogger.com0tag:blogger.com,1999:blog-4959692416650249872.post-50507822500295544922012-05-11T20:30:00.000-07:002013-04-23T09:57:07.242-07:00Tin prospecting in New Mexico<span style="font-size: x-small;"><span style="font-size: x-large;">A</span>bout a month ago I scheduled a trip to New Mexico to visit an online friend named Ted French, who runs a <a href="http://packwasher.freeyellow.com/micro.html">mineral shop</a>in Hillsboro, NM. He had offered to be my guide up into an area called the Taylor Creek Tin District where you can dry-wash for tin ore. </span><br /><span style="font-size: x-small;">Strange as this may seem to most people, I <i>liked</i> the idea, so I flew up to Albuquerque this past Monday, and spent Tuesday up in the Gila National Forest with Ted. </span><br /><br /><ul><li><span style="font-size: x-small;">We turned off US-25 onto New Mexico 52</span></li><li><span style="font-size: x-small;">We turned off New Mexico 52 onto County Road 59</span></li><li><span style="font-size: x-small;">We turned off County Road 59 onto Forest Service Road 2226 (or something)</span></li><li><span style="font-size: x-small;">Then we just turned off the road entirely.</span></li></ul><br /><div class="separator" style="clear: both; text-align: center;"><span style="font-size: x-small;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEg3gixnDkX4BGBfhnRAR6vUVaQ4JkEmPvlwz5OuWhxa2XxNnAoO_4bJJifjQIbwVM1LsnyXRJ8u4rDiRawfWMIQO8vy6TmVN5WA_QcRh0UfFiTA2oZN-h_1CE6-GfiU-sqmUjszwSvU8AE/s1600/hazard.png" imageanchor="1" style="clear: right; float: right; margin-bottom: 1em; margin-left: 1em;"><img border="0" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEg3gixnDkX4BGBfhnRAR6vUVaQ4JkEmPvlwz5OuWhxa2XxNnAoO_4bJJifjQIbwVM1LsnyXRJ8u4rDiRawfWMIQO8vy6TmVN5WA_QcRh0UfFiTA2oZN-h_1CE6-GfiU-sqmUjszwSvU8AE/s1600/hazard.png" /></a></span></div><span style="font-size: x-small;">On the "New Mexico 52" part we drove past a sign that said "Continental Divide". Kinda cool. On the "County Road 59" part we drove past a sign that said "Fire Hazard Risk: Extremely High". (Picture on right) Also kind of cool. Tellingly, there were no more signs after that.</span><br /><br /><span style="font-size: x-small;">Ted drove us through the pine-needle-carpeted forest to an unremarkable spot, and we got out of our trucks. Just over the hill was a dry creek bed that was our destination, and we walked up the bed togetther, with him pointing things out and giving instruction as we went.</span><br /><br /><span style="font-size: x-small;">We reached a a spot that suited Ted and plunked down our gear. He handed me a 35mm film container and a pair of huge tweezers. He note again which colors, textures and density of material I was looking for, and turned me loose. It was pretty plentiful. Tweeze-plunk, tweeze-plunk for several minutes, each "plunk" a pebble of tin ore. Meanwhile, he was scouting the next "good spot" and when I'd run dry I'd catch up with him and he'd get me started again. Shockingly it was pretty much that easy. I tweezed around an ounce fairly quickly. Ted could prospect faster than I could recover the material, so he started gathering ahead of me: finding the next spot for me, then a spot for him. In the time it took me to gather an ounce or so, he'd prospected ahead for both of us, tag-teamed the gear forward, and had time left over to recover... about 5 ounces. I am but dust. </span><br /><br /><span style="font-size: x-small;">During this time, the bright blue skies clouded over a bit, and we had a couple spritzes of rain. After the third spritz, when we'd been up there three hours or so, I decided that my two goals: first, to estimate how hard this task was, and second to gather a smeltable amount of tin ore, had both been accomplished. The rain was a bit dissuasive, so I was ready to go. Ted agreed, and just as we were starting to gather up the gear, it started to spritz again. By the time we had the gear rounded up, Ted was looking at the ground with a surprised expression.</span><br /><br /><span style="font-size: x-small;">"Is that <i>white</i>?" he asked. I held out my hands, and raindrops filled with a substantial amount of snow were hitting my arms. "That's sleet!" he said. "Cool weather!" I offered. We both grinned.</span><br /><br /><span style="font-size: x-small;">Then the thunder: loud and close at hand. Our smiles faltered. Up until now, "Thundersleet" had been a term with which I was unacquainted, but no longer. Thunder itself is not really scary, but its implied progenitor, Lightening, is a bit of an adrenaline rush when you're miles from the road, in a pine forest at 8500ft elevation, and distinctly remember a forest service sign saying "Fire Hazard Risk: Extremely High". Just imagine the thrills of a lightening strike between us and the roadway!</span><br /><br /><span style="font-size: x-small;">Happily, the Thundersleet ceased within a few minutes, just as we arrived back at the trucks.</span><br /><br /><div class="separator" style="clear: both; text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEiK5a5ttCMm-GH7GNsWlbN-WRcJVQBj4WOxA84ypuDsMDsS4H1VZnvzwEv9aiLMW9jWQSp890IvO1LRSvU86BS8jo3q3a4RYxyt0scnkJxncQroVaed8FWO94-rqDs4-Gkpa_zQDGRVbtw/s1600/hail_t.png" imageanchor="1" style="clear: right; float: right; margin-bottom: 1em; margin-left: 1em;"><img border="0" height="200" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEiK5a5ttCMm-GH7GNsWlbN-WRcJVQBj4WOxA84ypuDsMDsS4H1VZnvzwEv9aiLMW9jWQSp890IvO1LRSvU86BS8jo3q3a4RYxyt0scnkJxncQroVaed8FWO94-rqDs4-Gkpa_zQDGRVbtw/s200/hail_t.png" width="150" /></a></div><span style="font-size: x-small;">Less happily, it was replaced with (I am <i>not</i> making this up) thunder <i>hail.</i> Not seed- or pea-, but marble-sized hail poured down on us. The <i>very</i> loud and continuous clatter was overwhelmed occasionally by peals of thunder that (since we were at elevation, and quite close to the source) were that very loud sizzly-crackley thunder rather than the deep bass rumble you get when you're farther away. The hail was coming down so fast that by the time we got to the main road, we weren't driving on individual hailstones, but on a fairly well established half-inch-thick layer of hail on the road. I was <i>quite</i> glad that I'd decided to go with the added expense of real 4-wheel drive on the rental truck. One point for the rookie!</span><br /><br /><table cellpadding="0" cellspacing="0" class="tr-caption-container" style="float: right; margin-left: 1em; text-align: right;"><tbody><tr><td style="text-align: center;"><a href="http://www.youtube.com/watch?v=dps4JbMIKyk" imageanchor="1" style="clear: right; margin-bottom: 1em; margin-left: auto; margin-right: auto;"><img alt="Video of the hailstorm" border="0" height="162" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjhCzV0qa2Z0b5A6lBgdhxtVgnqRw6yxLlLpU8N7e5bnUQOD_V3E9H-l23Cubd8QlrsoPcced6IpcJWj0MKWvo9tYDa9ssFFXauOh08hORE5Vq1Ve7oQ5qH3v4LAWS2YPKIs6wwFCSUCvY/s200/hailstorm.png" title="Video of the hailstorm" width="200" /></a></td></tr><tr><td class="tr-caption" style="text-align: center;"><a href="http://www.youtube.com/watch?v=dps4JbMIKyk">Video of the hailstorm</a></td></tr></tbody></table><span style="font-size: x-small;">I relaxed a bit when we reached the actual blacktop. For a moment, picture yourself thinking of "Driving a big 4 wheel drive pickup truck for the first time, on a layer of hail, on a back-country county road" and being relieved.</span><br /><br /><br /><span style="font-size: x-small;">I finally thought to take some video of the hailstorm after it had started to wane a bit.</span><br /><br /><br /><br /><br /><span style="font-size: x-small;">The next odd bit was that when we passed the sign that said "continental divide" the sky was bright blue and there was no precipitation of any kind. The whole storm was trapped on the western side of the mountains. The rest of the drive home, or in my case to Albuquerque, was downright boring.</span><br /><br /><table cellpadding="0" cellspacing="0" class="tr-caption-container" style="float: right; margin-left: 1em; text-align: right;"><tbody><tr><td style="text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEiYjGksrWgQ2yP2-g0nqZ4hXJ46-pyIOrnnHEnbKYVPf_9WHhOlrBkkcpXX0UYZMWQ6gBysquaogAsK6T9nu9s3M_At6iLpAy5HLLogV_bcxiWgXQt06tdnB2gvUfP5qnKiFh0v-mmJJ28/s1600/clearweather_t.png" imageanchor="1" style="clear: right; margin-bottom: 1em; margin-left: auto; margin-right: auto;"><img border="0" height="200" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEiYjGksrWgQ2yP2-g0nqZ4hXJ46-pyIOrnnHEnbKYVPf_9WHhOlrBkkcpXX0UYZMWQ6gBysquaogAsK6T9nu9s3M_At6iLpAy5HLLogV_bcxiWgXQt06tdnB2gvUfP5qnKiFh0v-mmJJ28/s200/clearweather_t.png" width="150" /></a></td></tr><tr><td class="tr-caption" style="text-align: center;">... and it's clear skies</td></tr></tbody></table><table align="center" cellpadding="0" cellspacing="0" class="tr-caption-container" style="float: left; margin-right: 1em; text-align: left;"><tbody><tr><td style="text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhl_w4gcqgLfNGOrtaZ9VZh2V5fdSjsYagbRBaXomoiD00JKijVN_uD5YkqoOAHVXMMSGW-sV-78AxHXADK5-nE1lgRWy2mNaEGSUMWVb1aOYzmefuYorglExKbTZtWfkcuOpsghRXyD5o/s1600/divide_t.png" imageanchor="1" style="clear: right; margin-bottom: 1em; margin-left: auto; margin-right: auto;"><img border="0" height="126" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhl_w4gcqgLfNGOrtaZ9VZh2V5fdSjsYagbRBaXomoiD00JKijVN_uD5YkqoOAHVXMMSGW-sV-78AxHXADK5-nE1lgRWy2mNaEGSUMWVb1aOYzmefuYorglExKbTZtWfkcuOpsghRXyD5o/s200/divide_t.png" width="200" /></a></td></tr><tr><td class="tr-caption" style="text-align: center;">Then we cross the divide...</td><td class="tr-caption" style="text-align: center;"><br /></td></tr></tbody></table><br /><br /><br /><br /><br /><br /><br /><br /><br /><br /><br /><span style="font-size: x-small;">The net-net is that I came home safely, with enough raw tin ore to fiddle around with, having gathered the ore myself and gotten a feel for how hard that was to do: Mission Accomplished. The weather drama and new vocabulary were just a bonus. </span><br /><span style="font-size: x-small;"> </span><br /><br /><table align="center" cellpadding="0" cellspacing="0" class="tr-caption-container" style="margin-left: auto; margin-right: auto; text-align: center;"><tbody><tr><td style="text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEj3DXvMCSgXo6ardWtuPHbiLxCqMho3NmUWeESPdU2CEjvlsMEovB5mZiTNTmRY-OVFRpo5uqPmcZ6aH4OiR45JGmaP5xLx8GrM5YGgq7cS9jCN5Yb2g9eTstjIaqG5lTA9UtY2AfFcYlY/s1600/ounce_t.png" imageanchor="1" style="clear: right; margin-bottom: 1em; margin-left: auto; margin-right: auto;"><img alt="1 Oz Cassiterite" border="0" height="240" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEj3DXvMCSgXo6ardWtuPHbiLxCqMho3NmUWeESPdU2CEjvlsMEovB5mZiTNTmRY-OVFRpo5uqPmcZ6aH4OiR45JGmaP5xLx8GrM5YGgq7cS9jCN5Yb2g9eTstjIaqG5lTA9UtY2AfFcYlY/s320/ounce_t.png" title="1 Oz Cassiterite" width="320" /></a></td></tr><tr><td class="tr-caption" style="text-align: center;">Cassiterite.<br />About 1oz not counting the big lump.</td></tr></tbody></table><br /><div class="separator" style="clear: both; text-align: center;"></div><br /><table align="center" cellpadding="0" cellspacing="0" class="tr-caption-container" style="margin-left: auto; margin-right: auto; text-align: center;"><tbody><tr><td style="text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjMfNl8kzPzU6eNpRgVD617tU804luqPGmEhNYIq7-a4JwwSPYacpaihRdbv5_z73yWEPuV5BrqWu7k3soQZBdTj2BCcitlHq_84f9s7eCG8xUkNJUrTy1weXcoXd-NW6xi0FdkYe1hjPI/s1600/fitting_in.png" imageanchor="1" style="margin-left: auto; margin-right: auto;"><img border="0" height="284" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjMfNl8kzPzU6eNpRgVD617tU804luqPGmEhNYIq7-a4JwwSPYacpaihRdbv5_z73yWEPuV5BrqWu7k3soQZBdTj2BCcitlHq_84f9s7eCG8xUkNJUrTy1weXcoXd-NW6xi0FdkYe1hjPI/s320/fitting_in.png" width="320" /></a></td></tr><tr><td class="tr-caption" style="text-align: center;">Fitting in in New Mexico</td><td class="tr-caption" style="text-align: center;"><br /></td></tr></tbody></table><div class="separator" style="clear: both; text-align: center;"></div><br /><span style="font-size: x-small;">Now, off to crush the ore and smelt some tin!</span>Unknownnoreply@blogger.com0tag:blogger.com,1999:blog-4959692416650249872.post-15304738810924199362012-04-24T12:54:00.000-07:002013-04-23T09:57:07.341-07:00The Historical Metallurgy SocietyIf you're reading this blog, you will probably be fascinated by this document from <a href="http://www.hist-met.org/">The Historical Metallurgy Society</a>: "Metals and Metalworking, a research framework for achaeometallurgy". It's the best guide I've seen available online, bar none. You may even want to <a href="http://www.hist-met.org/join.html">become a member</a>.Unknownnoreply@blogger.com0tag:blogger.com,1999:blog-4959692416650249872.post-45010241791864523652011-07-16T15:43:00.000-07:002014-08-29T03:14:50.706-07:00Help finding malachtie source in the middle eastI lifted these images of a wide Malachite vein from a youtube video. The location is somewhere (according to the video, very remote) Middle East. Anyone know if there are human-accessible veins like this anywhere in the US? I'd happily pay a mine/claim owner for permission to take a few kilos from the ground myself.<br />
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<a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjGS-E5PTGQzNPShTS_IDi8PSktv84mouxAU9f5Z2eefSI-QavZMf69GAwoPjunStoLjPsqDvTNYd1N3U2Tme6-VtcneuNODxAVTQehwGKUbiiRm3qw_zRIRIfhvjHSfZF-zY9g3dq75gw/s1600/Vein+of+Malachite.jpg" imageanchor="1" style="margin-left: 1em; margin-right: 1em;"><img border="0" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjGS-E5PTGQzNPShTS_IDi8PSktv84mouxAU9f5Z2eefSI-QavZMf69GAwoPjunStoLjPsqDvTNYd1N3U2Tme6-VtcneuNODxAVTQehwGKUbiiRm3qw_zRIRIfhvjHSfZF-zY9g3dq75gw/s320/Vein+of+Malachite.jpg" height="286" width="320" /></a></div>
Unknownnoreply@blogger.com1tag:blogger.com,1999:blog-4959692416650249872.post-54156388381893381872010-07-05T20:37:00.000-07:002013-04-23T09:57:07.355-07:00Terminology: Furnace, Forge, KilnJust to keep <i>myself</i> from going crazy with these terms, I looked them up to find out which one meant what. According to Merriam-Webster...<br /><br />A<b> furnace </b>is the most generic term:<br /><blockquote><div class="d"> <strong>:</strong> an enclosed structure in which heat is produced (as for heating a house or for reducing ore)</div></blockquote><div class="d">A <b>kiln </b>narrows the uses to which the heat is put:</div><blockquote><div class="d"> <strong>:</strong> an oven, furnace, or heated enclosure used for processing a substance by burning, firing, or drying</div></blockquote>A <b>forge </b>narrows the thing being heated to a metal:<br /><blockquote><strong></strong><strong>:</strong> a furnace or a shop with its furnace where metal is heated and wrought<strong></strong></blockquote><div class="d"> </div><div class="d"> <strong></strong>So while most of the things I discuss here could use any of these terms, I'll try to use the term furnace generally. Of course the dictionary only records the <i>current</i> meaning of things, so older texts may contradict.</div>Unknownnoreply@blogger.com0tag:blogger.com,1999:blog-4959692416650249872.post-9611233150731143352010-06-28T18:42:00.000-07:002013-04-23T09:57:07.361-07:00A few more kindred spirits<a href="http://warehamforgeblog.blogspot.com/">Hammered Out Bits continues</a> to provide good iron smelting data at a tremendous rate.<br /><br />Lee Sauder and Skip Williams have a good page of iron smelting links at <a href="http://iron.wlu.edu/">The Rockridge Bloomery</a>. (Mel Brooks movie quotations aside) <br /><br />The <a href="http://www.earlyminesresearchgroup.org.uk/">Early Mines Research Group</a> has an ongoing smelting effort as well, check out the "experimental archeaology" and members-projects links.<br /><br />It looks like a lot of different people are (or recently have been) interested in early metal smelting re-creation, and I would love it if whoever catches the bug next had an easier time finding resources than I did, so please: send me your references.Unknownnoreply@blogger.com0tag:blogger.com,1999:blog-4959692416650249872.post-73388615840325069142010-06-27T18:10:00.000-07:002013-04-23T09:57:07.367-07:00Kindred SpiritsSome other folks are thinking along the same lines here, and I wanted to put up some links to their work as well. <br /><br />GrendelFish aka Matthew Dockrey recorded a couple of copper smelting expirments (<a href="http://www.cyphertext.net/%7Egfish/smelting.html">experiment 1</a> , <a href="http://www.cyphertext.net/%7Egfish/smelting2.html">experiment 2</a>) <br /><br />Tim Young at <a href="http://www.geoarch.co.uk/">GeoArch</a> has been running experiments and recording data for a succession of iron smelting efforts from <a href="http://www.geoarch.co.uk/experimental/experimental.html">1998 through 2007</a>. <br /><br />Paul French is starting a <a href="http://en.wikipedia.org/wiki/Experimental_Archaeometallurgy">wikipedia entry</a> that looks very promising.<br /><br /><a href="http://www.butserancientfarm.co.uk/">Butser Ancient Farm</a> has their <a href="http://www.butserancientfarm.co.uk/workshops2010.htm">2010 workshops</a> posted, and <a href="http://www.butserancientfarm.co.uk/workshops2010.htm#aug">Making Metals with Fergus Milton</a> on August 14 looks pretty interesting.<br /><br />See something else that needs to be on this list? Let me know!Unknownnoreply@blogger.com0tag:blogger.com,1999:blog-4959692416650249872.post-91976152149745200872010-06-17T02:25:00.000-07:002013-04-23T09:57:07.375-07:00Think like an engineer: Cheat!Faced with several smelting failures, I decided to apply one of the sacred tenets of practical engineering taught to me by my father: "When it won't work, cheat". I swapped out the clay forge for one made of loose-stacked firebricks, solving my spalling and insulation problems at a single blow. I was confident charcoal with forced air could get me the temperature I needed if I got a working geometry for the forge. Here's what I ended up with:<br /><br />[edit post to add picture here] <br /><br />Additionally a more knowledgeable copper smelter from the other side of the Atlantic Ocean, gave me some good advice about how to test for what was going wrong. (Thank you Fergus!) Armed with this information, and general his encouragement, I took another shot.<br /><br />On Wednesday, 16 Jun, 2010, I completed my first copper smelt. Here's a short (and very self-important) <a href="http://riventree.com/jeff/technosphere/metallurgy/smelting/copper/Copper.wmv">video</a> of the results.<br /><br />I plan to do another smelt tomorrow, on a slightly larger scale, so I'll take pictures and video, and post them.Unknownnoreply@blogger.com0tag:blogger.com,1999:blog-4959692416650249872.post-42156783062362518112010-06-01T19:05:00.000-07:002013-04-23T09:57:07.475-07:00Stack furnace v1.0: high firingNot to ruin the ending for you, but this is where stack furnace 1.0 started to go south. The previous day I had run two wood fires through to burnout in the forge, with no ill effects. Today I planned to do charcoal and forced air. While I had purchased bellows for this purpose, an acquaintance suggested that I just get a heat gun and some dryer duct from the hardware store, and start with that. Being short on time before my trip, I decided to go the surer route, and bought the gear.<br /><br /><br /><div class="separator" style="clear: both; text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgEfDyV2hGiK6eObrYD7XbBpFpe17Hx3CoJJwOCks7uADzZ5tUJ1SsWDIJ-3Ksi2jpX1H-w7G9eIFmTsfyRHJxF0-65vn8DyHgTk1YXRGoyy52uvmlmKQVAfzVbr5_NzTUlOQOifBN1SxU/s1600/HotFire+001.JPG" imageanchor="1" style="clear: left; float: left; margin-bottom: 1em; margin-right: 1em;"><img border="0" height="200" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgEfDyV2hGiK6eObrYD7XbBpFpe17Hx3CoJJwOCks7uADzZ5tUJ1SsWDIJ-3Ksi2jpX1H-w7G9eIFmTsfyRHJxF0-65vn8DyHgTk1YXRGoyy52uvmlmKQVAfzVbr5_NzTUlOQOifBN1SxU/s200/HotFire+001.JPG" width="150" /></a></div><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEj33VezJFCTbXW2NOD16cskPBjg0wE_8ZCjfi5AKyP1NMhXdHWWrSdvU0ciPi7831kgQCE-50Rxlk4v9O93SW41nqoPhaHLGDlqxmLD5c_DaKX9ZbIIy_eqWHrfN5gsmkjMblqH8IsaXq8/s1600/HotFire+010.JPG" imageanchor="1" style="clear: right; float: right; margin-bottom: 1em; margin-left: 1em;"><img border="0" height="200" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEj33VezJFCTbXW2NOD16cskPBjg0wE_8ZCjfi5AKyP1NMhXdHWWrSdvU0ciPi7831kgQCE-50Rxlk4v9O93SW41nqoPhaHLGDlqxmLD5c_DaKX9ZbIIy_eqWHrfN5gsmkjMblqH8IsaXq8/s200/HotFire+010.JPG" width="150" /></a><br /><div class="separator" style="clear: both; text-align: left;">The setup turned out to be quite easy. I loaded the furnace to the brim with charcoal, lit the pile from the bottom, used a wooden wedge to keep the duct in the tuyere, and sat down to watch, periodically removing the vent to reload the charcoal.</div><div class="separator" style="clear: both; text-align: left;"><br /></div><div class="separator" style="clear: both; text-align: left;">At the beginning of the first reload, I began to hear a curious sound, a lot like popcorn popping. Those more knowledgeable readers will be wincing right now, but after checking that there were no cracks or faults developing, I assumed it was some impurity in the charcoal and blithely continued. The next odd symptom was that the ash didn't seem to be burning as completely. There was a large accumulation of unburned crap in the bottom of the forge, and it continued to grow as I fed more charcoal into it.</div><div class="separator" style="clear: both; text-align: left;"><br /></div><div class="separator" style="clear: both; text-align: left;">The third symptom was clear, however: the edges of the tuyere cracked and widened it to about 200% (and later 300%) of its original size, causing the duct to drop out. At this point, with the better view into the forge afforded by the (now quite large) tuyere, I could see that the accumulation of "ash" was actually an accumulation of spalled clay. The popping noises were caused by fire-hardened clay cracking off as less hard (and still wet) clay behind it generated steam and popped it off.</div><div class="separator" style="clear: both; text-align: left;"><br /></div><div class="separator" style="clear: both; text-align: left;">The clay body was still too wet, and I was eroding my forge from the inside out. Below are some pictures of the whole thing, the inside, and a close up of one "edge" of the tuyere</div><br /><table><tbody><tr><td><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgd6em6t6x1vJddettbXaK5KiCuzp1_gLosevu2hjVXVTSCFWbBLND_ExPhnzWuKCH-D0jY4XbxkFlEi147f97JxkCu-5i4VicU053QQWbx9jMeyc1o87TUarJhqIIVD1gZ8Dl3x2TBqQA/s1600/Result+004.JPG" imageanchor="1"><img border="0" height="200" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgd6em6t6x1vJddettbXaK5KiCuzp1_gLosevu2hjVXVTSCFWbBLND_ExPhnzWuKCH-D0jY4XbxkFlEi147f97JxkCu-5i4VicU053QQWbx9jMeyc1o87TUarJhqIIVD1gZ8Dl3x2TBqQA/s200/Result+004.JPG" width="150" /></a></td> <td><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEiEVK2TtnO7ohvZQ1rvka6qDeOyu9FmPnvpmAZbjCzQbIbBlUItEOqEWIz3PRf5-bDXi4rjXN7mCBD4qENDjDeIpRRSjkfwq4MY2BLui6fmAYJoFatFzErVf7VefuqBxulvVNPKMcuZUtA/s1600/Result+002.JPG" imageanchor="1"><img border="0" height="150" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEiEVK2TtnO7ohvZQ1rvka6qDeOyu9FmPnvpmAZbjCzQbIbBlUItEOqEWIz3PRf5-bDXi4rjXN7mCBD4qENDjDeIpRRSjkfwq4MY2BLui6fmAYJoFatFzErVf7VefuqBxulvVNPKMcuZUtA/s200/Result+002.JPG" width="200" /></a></td> <td><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEheS_2XGBzlD2Z119GHjPEmNIRLkDJMTRwJrMyiHUlEyhED-fC20GVnhmm-yKgKmPU2w7W3aAKjn9YbGCLIwunAEmaCO4mNB44tseAA6G7wZ-2_wIYyPkSPgoZ_aEioWJMl2dW8KA1RnGI/s1600/Result+011.JPG" imageanchor="1"><img border="0" height="150" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEheS_2XGBzlD2Z119GHjPEmNIRLkDJMTRwJrMyiHUlEyhED-fC20GVnhmm-yKgKmPU2w7W3aAKjn9YbGCLIwunAEmaCO4mNB44tseAA6G7wZ-2_wIYyPkSPgoZ_aEioWJMl2dW8KA1RnGI/s200/Result+011.JPG" width="200" /></a></td> </tr></tbody></table><br /><br />Well, I was ready for my vacation anyway :)Unknownnoreply@blogger.com2tag:blogger.com,1999:blog-4959692416650249872.post-41799992417530416242010-06-01T18:36:00.000-07:002013-04-23T09:57:07.574-07:00Stack furnace v1.0: low firingAfter three days of drying indoors, then getting a good friend to help me get this back onto the patio, I split up some firewood into kindling sticks for the first (low) firing:<br /><br /><div class="separator" style="clear: both; text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEiCSELBEzbaQJNyLKh-iD6wNcQlKwWdXW4j_0wWt8NCn-IMTmdQX1bwYCHOirckLC3jagF4yIAUNjzyDq-690w9AQg273QUcoyK0qFDp5pn_Ze3qpQfQebXQ_rvYheOAPd8MPkRaU5AVCU/s1600/KindlingForDrying2.JPG" imageanchor="1" style="clear: right; float: right; margin-bottom: 1em; margin-left: 1em;"><img border="0" height="150" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEiCSELBEzbaQJNyLKh-iD6wNcQlKwWdXW4j_0wWt8NCn-IMTmdQX1bwYCHOirckLC3jagF4yIAUNjzyDq-690w9AQg273QUcoyK0qFDp5pn_Ze3qpQfQebXQ_rvYheOAPd8MPkRaU5AVCU/s200/KindlingForDrying2.JPG" width="200" /></a></div><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEggV8B5Kj8aP20ElmvDKf4d7D4n42g_oSh984gWaPg_mIMUkJjVlfmKoAPfgLt1p_nGJnIWXXTEEQVsIIrAI0QBuOcaDvFsgHv8qydxV_Uf_BKtOm5-5VavREuSbwvObkj4NVLZDaNHZL4/s1600/KindlingForDrying.JPG" imageanchor="1" style="clear: left; float: left; margin-bottom: 1em; margin-right: 1em;"><img border="0" height="150" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEggV8B5Kj8aP20ElmvDKf4d7D4n42g_oSh984gWaPg_mIMUkJjVlfmKoAPfgLt1p_nGJnIWXXTEEQVsIIrAI0QBuOcaDvFsgHv8qydxV_Uf_BKtOm5-5VavREuSbwvObkj4NVLZDaNHZL4/s200/KindlingForDrying.JPG" width="200" /></a><br /><br /><div class="separator" style="clear: both; text-align: left;">My current plan is to build a small fire inside the forge using just some kindling, and let that burn out. When that's cooled a bit, I'll start a second woodfire using logs, and let that burn for a while. A simple wood fire with no forced air isn't going to vitrify the clay, so this is an exercise in driving off water. Again, I can't find much in the way of advice on how to dry thick hunks of clay, so I'm flying blind.</div><br />Yes, it's on fire, but you can't really see it because the sun was quite bright that day.<br /><div class="separator" style="clear: both; text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjqMCZDJZlM0cTNOBtzSQedKY_viLgaoWDGAAaps19hO0ILfiWc5-o446du__qUP8GhGaKRXfrjCVa1BPyJVSWEnTWRNKEyApTNIUE0EAxkVDLMxnlPo_yT-mpAaMf0lz7CODMf5aIKDCY/s1600/LowFire.JPG" imageanchor="1" style="clear: left; float: left; margin-bottom: 1em; margin-right: 1em;"><img border="0" height="200" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjqMCZDJZlM0cTNOBtzSQedKY_viLgaoWDGAAaps19hO0ILfiWc5-o446du__qUP8GhGaKRXfrjCVa1BPyJVSWEnTWRNKEyApTNIUE0EAxkVDLMxnlPo_yT-mpAaMf0lz7CODMf5aIKDCY/s200/LowFire.JPG" width="150" /></a></div><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEik03lZK4tWOIesx8LxmDqUk_4XcMTOnauyF8m3GkEGL37NpcjTuqL3gUgWKv3D3LmFEYEVt26NLiN2e8L3tvQeGI80vVzAEMJp7DcOsGtq_cpqHBWqmxjcimAACcF6Sn2Uzp6x6937PFs/s1600/LowFire2.JPG" imageanchor="1" style="clear: right; float: right; margin-bottom: 1em; margin-left: 1em;"><img border="0" height="150" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEik03lZK4tWOIesx8LxmDqUk_4XcMTOnauyF8m3GkEGL37NpcjTuqL3gUgWKv3D3LmFEYEVt26NLiN2e8L3tvQeGI80vVzAEMJp7DcOsGtq_cpqHBWqmxjcimAACcF6Sn2Uzp6x6937PFs/s200/LowFire2.JPG" width="200" /></a><br /><br /><div class="separator" style="clear: both; text-align: left;">Burn 1 went to completion without a hitch: no spalling of the clay at all, and a nice hard surface resulted on the inside. Round two, with the bigger logs, begins.</div><br /><div class="separator" style="clear: both; text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgAh8ZXUGn9_sh7UrkMlk9NbG7m7vz7Fyc1LUX6gZ4KH6X2XH4p671TC9t-alZGBPzXDToi9y40u2RiufUflyKeFX7eHVNnHq_jh1PXAPeN2qs2GsRUCUBv7jpqI3P0t-d7h9AUrdTqGsY/s1600/MedFire1.JPG" imageanchor="1" style="clear: right; float: right; margin-bottom: 1em; margin-left: 1em;"><img border="0" height="200" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgAh8ZXUGn9_sh7UrkMlk9NbG7m7vz7Fyc1LUX6gZ4KH6X2XH4p671TC9t-alZGBPzXDToi9y40u2RiufUflyKeFX7eHVNnHq_jh1PXAPeN2qs2GsRUCUBv7jpqI3P0t-d7h9AUrdTqGsY/s200/MedFire1.JPG" width="150" /></a></div><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEiId99nHmyEFV1zOY4cRHcQP0iehrTLoGMAxpVFWJD5LDkgQTs1NrVBGCE-j2MFww7t9TU6h_ry6g3HD8W79oRwBt83Q7Skx4KpvApppXS1UUCUozMHJSIY9920m0oUHWR9qnYUCU0jQ6Y/s1600/MedFire.JPG" imageanchor="1" style="clear: left; float: left; margin-bottom: 1em; margin-right: 1em;"><img border="0" height="200" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEiId99nHmyEFV1zOY4cRHcQP0iehrTLoGMAxpVFWJD5LDkgQTs1NrVBGCE-j2MFww7t9TU6h_ry6g3HD8W79oRwBt83Q7Skx4KpvApppXS1UUCUozMHJSIY9920m0oUHWR9qnYUCU0jQ6Y/s200/MedFire.JPG" width="150" /></a><br /><br /><div class="separator" style="clear: both; text-align: left;">This also went well, although it took a lot longer than I'd hoped. To keep the fire "in" the forge, I had to keep chopping away at the lower parts of the wood to get them out of the way so the fresh (burning) wood was below the top.</div><br /><br /><div class="separator" style="clear: both; text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhSiCRTdDl1NOgoBhYt1vp6mAct5dmFy9K1bQeMclxoL7n9VE8IOqhuKfVzHTRTNOHkeVbf_-_hRJDnwzeFHnFDX_zezPI1iYmqjAkXi6L1TxNDii1pnEVaAZnL5t0ZbK3jwU3eB9GlVf4/s1600/AfterLowFire2.JPG" imageanchor="1" style="clear: right; float: right; margin-bottom: 1em; margin-left: 1em;"><img border="0" height="200" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhSiCRTdDl1NOgoBhYt1vp6mAct5dmFy9K1bQeMclxoL7n9VE8IOqhuKfVzHTRTNOHkeVbf_-_hRJDnwzeFHnFDX_zezPI1iYmqjAkXi6L1TxNDii1pnEVaAZnL5t0ZbK3jwU3eB9GlVf4/s200/AfterLowFire2.JPG" width="150" /></a></div><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEi8S4haO4Av6DCJ-hDAT5cb2iEp2YRzUtyMdI_lrcIxdtvP2FUTTdf3zsSUzqtiVuGY2P_xkSVMhPqxhL7wjlcDj3Et9dL7Ab5bHPtmHnYmWRBHqm_uAKzO5BCXrgeXZ8QA1WSEJ3NdSYQ/s1600/AfterLowFire.JPG" imageanchor="1" style="clear: left; float: left; margin-bottom: 1em; margin-right: 1em;"><img border="0" height="200" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEi8S4haO4Av6DCJ-hDAT5cb2iEp2YRzUtyMdI_lrcIxdtvP2FUTTdf3zsSUzqtiVuGY2P_xkSVMhPqxhL7wjlcDj3Et9dL7Ab5bHPtmHnYmWRBHqm_uAKzO5BCXrgeXZ8QA1WSEJ3NdSYQ/s200/AfterLowFire.JPG" width="150" /></a><br /><br /><div class="separator" style="clear: both; text-align: left;">As you can see, the second firing went well. There was either a <i>little</i> spalling, or there wasn't any, and I just cleaved off some loose ash/clay when cleaning the coals, but either way, there are no cracks or major cleaves, so I'm ready to move on to the High Firing!</div>Unknownnoreply@blogger.com0tag:blogger.com,1999:blog-4959692416650249872.post-47169438973128733872010-06-01T18:11:00.000-07:002013-04-23T09:57:07.672-07:00Stack furnace v1.0: The clayworkNow based on several articles, videos, and some photos found online, I've decided to build what I <i>think</i> should be termed a clay stack furnace. I will create a small pocket of high temperature surrounded by reflective (or at least insulative) material. Thus the heat energy will stay trapped in that area, rather than leaving via the flue/chimney.<br /><br />Shopping for high-cone clay turned out to be the hardest part. I knew I was going to be pushing all sorts of temperature boundaries in the pocket, so I didn't want to mess with something that would melt, slag, or droop below that. Unfortunately, my local bigbox stores, craft stores, and even school supply stores didn't carry anything beyond air- or oven- dry clay. I went to a couple of the boutique paint-your-own pottery places, and although they sometimes sell clay, they had none. Even the specialist art supply place on the edge of town only occasionally carried pottery clay, and that was neither high-cone nor in stock. <sigh> Much gas wasted driving around, so I returned home and started calling around.</sigh><br /><br />In fact the nearest place that was open and selling cone-10 clay was the student store at a college about an hour's drive out of town. Happily, they were dumping their stock at the end of the semester, and had 35-40 kilos at "sub cost" prices. Whee!<br /><br />OK, so now I have clay, but I'm no potter, so I have <i>no</i> idea what I'm doing as far as construction, drying time, firing time/temp, etc. A quick browse through the internet does not reveal much in the way of "how long do you let a 5cm thick wall of clay dry before you fire it?". Most of the instructions are for dainty little teacups or objets d'art. The five large cubes of clay made me bold, and I decided to just forge ahead. (No pun intended)<br /><br /><div class="separator" style="clear: both;"><table width=100% border=0 cellpadding=0><tbody><tr><td valign=top>First layer</td><td><br /><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhElCElBHSJPSYGiiVWcjzA2mzUQuvrvQwJVm7TNM6NallXaky2cD_pGMVAVbVxtBtMAZy8HG16mkjupCapf66Q5xEJaTNk0kcibSTU22CBNee__d8V-q75WE6HnxTQ2Ql5MIH49fzFGX4/s1600/Level1.1.JPG" imageanchor="1"><img border="0" height="200" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhElCElBHSJPSYGiiVWcjzA2mzUQuvrvQwJVm7TNM6NallXaky2cD_pGMVAVbVxtBtMAZy8HG16mkjupCapf66Q5xEJaTNk0kcibSTU22CBNee__d8V-q75WE6HnxTQ2Ql5MIH49fzFGX4/s200/Level1.1.JPG" width="150" /></a></td></tr><tr><td valign=top>Second layer</td><td><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjL_fvoimNfq4ilANUHkhToyEPcpAFm3itIwdtjiCjkK7toNRGSA6fJCIw1FagdJcaY7kIVvMQ1Oe_CCGmSmCP12Bvf2plWJtXG-gYJp74X-aswRZBIh-V9JGP85uTaLEsFzXf_-7Vr8nI/s1600/Level2.1.JPG" imageanchor="1"><img border="0" height="150" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjL_fvoimNfq4ilANUHkhToyEPcpAFm3itIwdtjiCjkK7toNRGSA6fJCIw1FagdJcaY7kIVvMQ1Oe_CCGmSmCP12Bvf2plWJtXG-gYJp74X-aswRZBIh-V9JGP85uTaLEsFzXf_-7Vr8nI/s200/Level2.1.JPG" width="200" /></a></td></tr><tr><td valign=top>Third Layer</td><td><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjugK-xys0MLsWuDt7VBcVCdJt0ekRYrq-s477Gkzc-2vRTPfkKnpNTmZdO103CaPKIL-1rQQ8pBBYpthTCqkcuwGNik_Eiqe1nswJiQq3vNOZuf_9Ttlb_NrBqrexNhTvK6xkSsPsVP2U/s1600/Level3.1.JPG" imageanchor="1"><img border="0" height="150" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjugK-xys0MLsWuDt7VBcVCdJt0ekRYrq-s477Gkzc-2vRTPfkKnpNTmZdO103CaPKIL-1rQQ8pBBYpthTCqkcuwGNik_Eiqe1nswJiQq3vNOZuf_9Ttlb_NrBqrexNhTvK6xkSsPsVP2U/s200/Level3.1.JPG" width="200" /></a></td></tr><tr><td valign=top>Fourth and fifth layers</td><td><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjXLxpBjhr-DwwlbtJ1X7q5J8D5vGK1bfyyl67lmUTXp1n09gISDfxkHC2cwSXJtWnLW3W4I8GnUlKv4aexOuYNfhpjz6oyARTVdi0PlEkaAAPw0ql_xvFChMz4i9VH6pWy-Y8byV5nJAM/s1600/Finished1.JPG" imageanchor="1"><img border="0" height="150" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjXLxpBjhr-DwwlbtJ1X7q5J8D5vGK1bfyyl67lmUTXp1n09gISDfxkHC2cwSXJtWnLW3W4I8GnUlKv4aexOuYNfhpjz6oyARTVdi0PlEkaAAPw0ql_xvFChMz4i9VH6pWy-Y8byV5nJAM/s320/Finished1.JPG" /width="200"></a></td></tr><tr><td valign=top>Inside view, after smoothing</td><td><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgL4U_uh1cIJJ60fKlkLqeF9UjHabfQo3MXLskm75X5F6qzVEtZrNbcCNaNcK6cjHY5KaS8Z5yjVMRvBZusuabKztY3_w-nMsiquHQLfzISbBlH7pspEMN7qDXud6gLWP9dG41gBQztsnw/s1600/FinishedInside2.JPG" imageanchor="1"><img border="0" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgL4U_uh1cIJJ60fKlkLqeF9UjHabfQo3MXLskm75X5F6qzVEtZrNbcCNaNcK6cjHY5KaS8Z5yjVMRvBZusuabKztY3_w-nMsiquHQLfzISbBlH7pspEMN7qDXud6gLWP9dG41gBQztsnw/s320/FinishedInside2.JPG" /></a></td></td></tbody></table></div><br />Basically I started with a tight little horseshoe shape, built on that, then closed the tuyere at the top, and built it up a bit taller.<br /><br />When I was done, I realized that I had expanded the internal volume considerably beyond what I had originally intended, so I sliced (vertically) a couple of chunks out of the sides, dampened the edges, and stuck them back together firmly. While I fully expected this to result in faults during firing, this did not happen: apparently working the edges enough resulted in a good "weld". The removed clay I placed on top again, making the stack still taller.<br /><br />Finally I wet my hands a bit, and smoothed and compressed all the surfaces. Yes, smooth is a relative term, but I reasoned that reducing the surface area would increase heat reflection and decrease heat absorption. Likewise, the opportunity to compress the sides together would hopefully knead out any larger air pockets. This was by far the quickest part of the build.<br /><br />So now I have this... er... thing. I know it's got a lot of water content: I didn't add water to the clay out of the box, but it was still pliable, so its water content was not zero, and I did wet my hands for the smoothing effort, and the clay drank that water in.<br /><br />Looking up drying times on the web, I get a variety of answers: from 36 hours in Arizona to ten days in Minnesota. Since I'm leaving on a trip in four days (on April 28) I decide to try for three days. Moving this (base + forge) off my patio and into the relative dry of my apartment was a big job, and bringing it out again was going to be another one. Happily, family and friends were understanding enough to help.Unknownnoreply@blogger.com0tag:blogger.com,1999:blog-4959692416650249872.post-80668729529886873812010-06-01T17:21:00.000-07:002013-04-23T09:57:07.769-07:00New platform for builds<div class="separator" style="clear: both; text-align: center;"></div>In the previous post, I wondered about building a forgelet inside my chiminea. After evaluating some of the dimensions involved, I thought this would be a problem, given the limiting size of the "mouth". <br /><br /><br />So I decided to take a different route. One sunny day in mid-April saw me on another building spree: No matter what I eventually designed, I was going to need to build it somewhere, and a platform of some sort would be needed. A standing garden firepit kit, sand, and firebricks formed the base. A full sized fire extinguisher bottle was also called for.<br /><br /><div class="separator" style="clear: both; text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgAR719VgXe4G6hKqz-aaOvU3vDVCWRTfOpVaGpMi7kWXgA-tA6idp8bfKwg6e0QFwJVY_2LtVgvKzumt1tY99hMqbeHl4X0yUuAMdWVm6ygAId8QMKrzfM9Es6tdmunog3eG098sgiNVE/s1600/Firepit+%282%29.JPG" imageanchor="1" style="margin-left: 1em; margin-right: 1em;"><img border="0" height="150" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgAR719VgXe4G6hKqz-aaOvU3vDVCWRTfOpVaGpMi7kWXgA-tA6idp8bfKwg6e0QFwJVY_2LtVgvKzumt1tY99hMqbeHl4X0yUuAMdWVm6ygAId8QMKrzfM9Es6tdmunog3eG098sgiNVE/s200/Firepit+%282%29.JPG" width="200" /></a></div><br /><table align="center"><tbody><tr><td width="30%"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhmc-Jfu-gaYU9XSrF042W3CIw_NWwlVF1X1rr2Zh2BZGi9OYnLvJCXTz4TqCBiuhpsbul2RSpOBclUvn6sCBvmjAFDo19ivCjXO0VEoVXrcTdO7XLllvp99JAcNaFtrqf3ivsE1gYrSsY/s1600/PlugHolesWithClay+%282%29.JPG" imageanchor="1"> <img border="0" height="200" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhmc-Jfu-gaYU9XSrF042W3CIw_NWwlVF1X1rr2Zh2BZGi9OYnLvJCXTz4TqCBiuhpsbul2RSpOBclUvn6sCBvmjAFDo19ivCjXO0VEoVXrcTdO7XLllvp99JAcNaFtrqf3ivsE1gYrSsY/s200/PlugHolesWithClay+%282%29.JPG" width="150" /></a><br /></td><td width="30%"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEiLx_Jzh1e7UjEAEx9VCLDU-B3MZoAEo_2k4macKWCg-yLzzhbCpAutBSlO4yskdVjJR3SulrRrNMaDBi2f2EQ6-Q15lr7WjJUTjLl9fHtpoJwgdDpcXKHaRcfd2GJ0Ro4eIxDfFluxOl0/s1600/FillWithSand+%283%29.JPG" imageanchor="1"> <img border="0" height="200" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEiLx_Jzh1e7UjEAEx9VCLDU-B3MZoAEo_2k4macKWCg-yLzzhbCpAutBSlO4yskdVjJR3SulrRrNMaDBi2f2EQ6-Q15lr7WjJUTjLl9fHtpoJwgdDpcXKHaRcfd2GJ0Ro4eIxDfFluxOl0/s200/FillWithSand+%283%29.JPG" width="150" /></a><br /></td><td width="30%"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjgfbjhdBFCFQHBldFSLYBP9MraeEDyBoJLBHrszTGkm_8W6VALpXuJYIvcVC27aIcS1_AqWOyO0PAqaaV9LIhkRjBI3LgW5e9yJk3DDc5gJ3N2dtlkjIgfdt8NsRqocFBVoIcagAbPLLI/s1600/LayFireBricks.JPG" imageanchor="1"> <img border="0" height="200" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjgfbjhdBFCFQHBldFSLYBP9MraeEDyBoJLBHrszTGkm_8W6VALpXuJYIvcVC27aIcS1_AqWOyO0PAqaaV9LIhkRjBI3LgW5e9yJk3DDc5gJ3N2dtlkjIgfdt8NsRqocFBVoIcagAbPLLI/s200/LayFireBricks.JPG" width="150" /></a></td></tr></tbody></table><br />Fireproof, sturdy, and good defense against high temperatures.<br /><br />Onwards!Unknownnoreply@blogger.com0tag:blogger.com,1999:blog-4959692416650249872.post-78809613681654635292010-04-18T14:11:00.000-07:002013-04-23T09:57:07.867-07:00Added a pageCheck out the "Cold Forge Resources" page.Unknownnoreply@blogger.com0tag:blogger.com,1999:blog-4959692416650249872.post-33031264170773826312010-04-15T19:37:00.000-07:002013-04-23T09:57:07.963-07:00Core problem: low temperatureThe news turned out to be bad-ish. After another trial where I severely limited the available oxygen, it appears the core forge temperature was only getting up to 1000-1050C: not *quite* enough to smelt the copper. I've got two ideas for dealing with this:<br /><br /><ol><li>Improve (radically) the airflow, and use more fuel. More combustion in less time == higher temp. Maybe a hair dryer or something to keep the air full-blast full-time.</li><li>Build a smaller, "forge" within the chiminea. Perhaps something more historically accurate will keep more heat in a smaller volume and raise the working temperature.</li></ol>Not sure which way I'll go yet. I think #2 would be more satisfying, but I can probably implement #1 in a single day.<br /><br />-JeffUnknownnoreply@blogger.com0tag:blogger.com,1999:blog-4959692416650249872.post-23692106176105817162010-04-11T01:10:00.000-07:002013-04-23T09:57:08.062-07:00Which way now?In diagnosing my previous problem, I know that an insufficiently reducing environment will yield copper oxides rather than copper metal. Unfortunately, insufficient heat will yield exactly the same thing, so that doesn't help. However, if the problem is low temperature, then it's going to be a real issue. Too much oxygen, on the other hand, is relatively easy to solve, so I'll start with that.<br /><div class="separator" style="clear: both; text-align: center;"></div><br />I took the copper oxides from smelts 1 & 2 and crushed them in a mortar and pestle. This yielded somewhat-fine oxide powder, which I put into the terracotta saucers<br /><div class="separator" style="clear: both; text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgiB6Ox15rkg-G1y7rd6gxsb8HYV4la8uhGdRjmtAkF_XJKFQkGmdKHPYVPZh5JCkUxzuOz1IooBc2A36mp8T-uXajJWe_s2UWBx94fibp1S7e4p_HkHgROost0Hvgr_q9BYAj4uJLFi34/s1600/Zark+034.JPG" imageanchor="1" style="clear: right; float: right; margin-bottom: 1em; margin-left: 1em;"><img border="0" height="200" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgiB6Ox15rkg-G1y7rd6gxsb8HYV4la8uhGdRjmtAkF_XJKFQkGmdKHPYVPZh5JCkUxzuOz1IooBc2A36mp8T-uXajJWe_s2UWBx94fibp1S7e4p_HkHgROost0Hvgr_q9BYAj4uJLFi34/s200/Zark+034.JPG" width="150" /></a><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEiy3kULAjq8kYelvWiUAEZ4Rk6pdpvMkjC97EG-vbwBYrvUO4LStyeKLfIfR-Tii0R1bxL841t3lhoaVYLc8ch2-GjeJbtTgsotUtPkymvyJMpVQB5qAu40EBObXemF4kiyvzH7W0T8bOc/s1600/Zark+032.JPG" imageanchor="1" style="clear: left; float: left; margin-bottom: 1em; margin-right: 1em;"><img border="0" height="200" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEiy3kULAjq8kYelvWiUAEZ4Rk6pdpvMkjC97EG-vbwBYrvUO4LStyeKLfIfR-Tii0R1bxL841t3lhoaVYLc8ch2-GjeJbtTgsotUtPkymvyJMpVQB5qAu40EBObXemF4kiyvzH7W0T8bOc/s200/Zark+032.JPG" width="150" /></a></div><br /><div class="separator" style="clear: both; text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjuRU3nQvt8pTEkR8Jv1KGcTAGg3FLBnimTT9EgXBHSL1opeXsmMiCl44F0C_4Y-rWw6Fwumx6YUAZKZ7OZfGhpkx5k6F2nnoIYaOioGoyZFncO3GBPNLrXsUjSJaTGK1EgSyO-Ld1QGS8/s1600/Zark+048.JPG" imageanchor="1" style="clear: right; float: right; margin-bottom: 1em; margin-left: 1em;"><img border="0" height="200" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjuRU3nQvt8pTEkR8Jv1KGcTAGg3FLBnimTT9EgXBHSL1opeXsmMiCl44F0C_4Y-rWw6Fwumx6YUAZKZ7OZfGhpkx5k6F2nnoIYaOioGoyZFncO3GBPNLrXsUjSJaTGK1EgSyO-Ld1QGS8/s200/Zark+048.JPG" width="150" /></a><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhrgFn9cYyX7yrKZq3frlo2EnLGfyHSXsSAi47flLBb7TXdVpPAd7qhNdCjeGH_SdRubAEv__1sZjoalYY7ShNTQMdlXNb0v5IOFqOpJhTI62aDrMDMrRxjx9bulrQWIi8nnIcQGsqqwII/s1600/Zark+046.JPG" imageanchor="1" style="clear: left; float: left; margin-bottom: 1em; margin-right: 1em;"><img border="0" height="200" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhrgFn9cYyX7yrKZq3frlo2EnLGfyHSXsSAi47flLBb7TXdVpPAd7qhNdCjeGH_SdRubAEv__1sZjoalYY7ShNTQMdlXNb0v5IOFqOpJhTI62aDrMDMrRxjx9bulrQWIi8nnIcQGsqqwII/s200/Zark+046.JPG" width="150" /></a></div><div class="separator" style="clear: both; text-align: center;"></div><br /><br />Now I plan to get a little extra clay, and seal the saucers together, top and bottom leaving a small hole for a little gaseous expansion, mix in a little charcoal dust to absorb any low-hanging fruit on the oxygen tree, and fire up the forge once again.<br /><br />Hopefully, these little saucers will be half-filled with circular copper ingots at the end of the process <br /><br />Wish me luck!Unknownnoreply@blogger.com0tag:blogger.com,1999:blog-4959692416650249872.post-20219571651143126082010-04-11T00:49:00.000-07:002013-04-23T09:57:08.160-07:00Past efforts: Smelt 2, partial successI wanted to compare the various containers, so I tried some open to the flame (cast iron servers, 1 terracotta cup) and some closed (2 clamshelled cups, 2 stacked ramekins)<br /><div class="separator" style="clear: both; text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhQfFQAfgR1HGwRaacyruoB0njEbxuF0AaqMGqwbkkADnVfCTGETB6W_JnCOt54y28O-ie2qy8fMUQrPh7O1yNFZNBBF-R369J2WOBy-PFGshr3cKPYojTxMRyLhksii4AmD0XnzqogmsY/s1600/SmeltingMalachite+016.JPG" imageanchor="1" style="margin-left: 1em; margin-right: 1em;"><img border="0" height="240" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhQfFQAfgR1HGwRaacyruoB0njEbxuF0AaqMGqwbkkADnVfCTGETB6W_JnCOt54y28O-ie2qy8fMUQrPh7O1yNFZNBBF-R369J2WOBy-PFGshr3cKPYojTxMRyLhksii4AmD0XnzqogmsY/s320/SmeltingMalachite+016.JPG" width="320" /></a></div><br /><div class="" style="clear: both; text-align: left;">I put them in the bottom of the forge, and piled in the charcoal.</div><div class="separator" style="clear: both; text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEiGgdCEuD_sg5bf-xbmoEcgALtuQz_JQ5j8d08IVjrwlj9V72k1M167hZjXuH7_XD8mtpz918vwXwKKqZURqRimkf6uN7E4hG0M_P91J5zMnw1OuMkbxbbSODFY4f8GWsKOWAPHdQ7zVoU/s1600/SmeltingMalachite+017.JPG" imageanchor="1" style="margin-left: 1em; margin-right: 1em;"><img border="0" height="240" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEiGgdCEuD_sg5bf-xbmoEcgALtuQz_JQ5j8d08IVjrwlj9V72k1M167hZjXuH7_XD8mtpz918vwXwKKqZURqRimkf6uN7E4hG0M_P91J5zMnw1OuMkbxbbSODFY4f8GWsKOWAPHdQ7zVoU/s320/SmeltingMalachite+017.JPG" width="320" /></a></div><div class="separator" style="clear: both; text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgnjcHEsEkflyt_nKNTu5UtG5qmF0w28EzjTWcwcPlsB1JQZt_JHjyQZLaisf7Xvc2jIu0tY_6Qg46Wo_M5I08bNegLBxJN-8YshIA3mz0bIER4gLZhIWjKp7kPJ6LHnz6EoMfPDAp85AQ/s1600/SmeltingMalachite+019.JPG" imageanchor="1" style="margin-left: 1em; margin-right: 1em;"><img border="0" height="400" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgnjcHEsEkflyt_nKNTu5UtG5qmF0w28EzjTWcwcPlsB1JQZt_JHjyQZLaisf7Xvc2jIu0tY_6Qg46Wo_M5I08bNegLBxJN-8YshIA3mz0bIER4gLZhIWjKp7kPJ6LHnz6EoMfPDAp85AQ/s400/SmeltingMalachite+019.JPG" width="300" /></a></div><div class="" style="clear: both; text-align: left;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgg6QRrh8lKybWOhEzMKWFz4F7eEE3K1LpzLyhHt70kAcQVUOK_oMiY1NHAohS6VsmUlq9-VhFAicwCGxa47Gv9GFJ_u7cxH3nfcWOBV_nAYHKj1TgS7dW4Wq3MS9BIk5Asqubc43ZkOCk/s1600/SmeltingMalachite+022.JPG" imageanchor="1" style="clear: right; float: right; margin-bottom: 1em; margin-left: 1em;"><img border="0" height="150" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgg6QRrh8lKybWOhEzMKWFz4F7eEE3K1LpzLyhHt70kAcQVUOK_oMiY1NHAohS6VsmUlq9-VhFAicwCGxa47Gv9GFJ_u7cxH3nfcWOBV_nAYHKj1TgS7dW4Wq3MS9BIk5Asqubc43ZkOCk/s200/SmeltingMalachite+022.JPG" width="200" /></a><br />Each container had a mix of large chunks of broken malachite and ground charcoal. I lit the fire and started a'blowin. I reloaded the fuel several times, eventually using the entire bag of charcoal. Once the entire thing had burned down to a bit of ash and a few glowing coals, I extracted the various containers. The cast iron server looked like this. (the circle on the right is the open terracotta saucer)</div><br /><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhmuenMDVEXHIKEEarJVt6wqf2jT3V75Bnjqr7mrEJnvS_VvKY98xcVtv3-LKLFnmhma9e5eYCXkHsIqRu3ZSlNy6ZgF0KdqjYe7dUaRoeV291DGsPpsMludlBAvnHC4BcBaarJjamXirA/s1600/SmeltingMalachite+023.JPG" imageanchor="1" style="clear: right; float: right; margin-bottom: 1em; margin-left: 1em;"><img border="0" height="150" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhmuenMDVEXHIKEEarJVt6wqf2jT3V75Bnjqr7mrEJnvS_VvKY98xcVtv3-LKLFnmhma9e5eYCXkHsIqRu3ZSlNy6ZgF0KdqjYe7dUaRoeV291DGsPpsMludlBAvnHC4BcBaarJjamXirA/s200/SmeltingMalachite+023.JPG" width="200" /></a>Safety tip: beware hidden coals... as I started to empty this (by hand, the cast iron was cool enough to touch) I found this guy hiding in the ash...<br /><br />Ipicked out the larger chunks more gingerly, and ended up with the same result: a lot of ash-looking stuff, and no pooled copper in the bottom of any of the containers. Then I started noticing a terracotta-colored brittle substance at the bottom of each of the containers. It was fragile and brittle, but not charcoal, and it was present in all the containers, so it wasn't shards of pottery.<br /><br />I decided that it must be partly red copper oxide (Cu<sub>2</sub>O) encased in black copper oxide (CuO), which looked a lot like little chunks of charcoal. This meant that I'd partially reduced the malachite, but didn't actually get to a liquid copper state.<br /><br /><div class="separator" style="clear: both; text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgqdX-TZM_S-_rAvc1GgATwu9A9Z2VSrWdhSUekKebYm-xe6nk77Gj4lzyXFOSsDpatvA-G2HYtRop89Zjtsx6aQIjLH_ANTHa8YlbUXzDnIgCYabyQ4qgKcsYOBmRQhlMUQPXt-lpDgo4/s1600/SmeltingMalachite+025.JPG" imageanchor="1" style="clear: right; float: right; margin-bottom: 1em; margin-left: 1em;"><img border="0" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgqdX-TZM_S-_rAvc1GgATwu9A9Z2VSrWdhSUekKebYm-xe6nk77Gj4lzyXFOSsDpatvA-G2HYtRop89Zjtsx6aQIjLH_ANTHa8YlbUXzDnIgCYabyQ4qgKcsYOBmRQhlMUQPXt-lpDgo4/s320/SmeltingMalachite+025.JPG" /></a></div>But now I was faced with a problem: I had copper oxide chunks and charcoal that both looked like small black brittle lumps. How could I separate them? After spending 5 minutes teasing them apart and sorting them visually (the charcoal always had striations in the surface) the "idea" light over my head started glowing weakly. Carbon floats, ash is partly soluble, and copper oxides are insoluble. Enter the sophisticated scientific apparatus known as "a glass of water":<br /><br /><br /><br /><br /><div class="separator" style="clear: both; text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhMRZYOPXE3mVkm2N0Q3bvykknFseut7RY-KV6HOO4ceTCD0xg1Kxr7RIM1o_TS3-Xy7pjS0BRjig3gXH1hYyVJMiorFb_qYCgStdukZqFBk3f7DBylKsNVTP5k4cWLH-_3zB2xxAMtnP8/s1600/SmeltingMalachite+028.JPG" imageanchor="1" style="clear: right; float: right; margin-bottom: 1em; margin-left: 1em;"><img border="0" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhMRZYOPXE3mVkm2N0Q3bvykknFseut7RY-KV6HOO4ceTCD0xg1Kxr7RIM1o_TS3-Xy7pjS0BRjig3gXH1hYyVJMiorFb_qYCgStdukZqFBk3f7DBylKsNVTP5k4cWLH-_3zB2xxAMtnP8/s320/SmeltingMalachite+028.JPG" /></a></div>After fishing out the charcoal lumps from the froth, and draining and refilling the glass several times (being careful not to tip out any copper from the bottom) I ended up with the copper oxide "lode" at the bottom of the glass. The black lumps are <i>not</i> charcoal nibs, they're black-jacketed copper oxide.<br /><br />Remembering my leftover "ash" from smelt #1, I emptied that into the glass as well. Presto, more copper. I hadn't made it vanish after all.<br /><br /><br /><br /><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjSrTXVArAxnx4vUFzEeNptdjO7l24TQXov_SQvsWYsHROl_AyWiCwZgg9MsexxU_WpPFaJ1EV0js4p0qz9HcujT5Y8Y-y2t7OYXgiOx8907QhvDl9PBCzC52zc0g3W5zG8LKRB_513OuA/s1600/SmeltingMalachite+033.JPG" imageanchor="1" style="clear: right; float: right; margin-bottom: 1em; margin-left: 1em;"><img border="0" height="150" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjSrTXVArAxnx4vUFzEeNptdjO7l24TQXov_SQvsWYsHROl_AyWiCwZgg9MsexxU_WpPFaJ1EV0js4p0qz9HcujT5Y8Y-y2t7OYXgiOx8907QhvDl9PBCzC52zc0g3W5zG8LKRB_513OuA/s200/SmeltingMalachite+033.JPG" width="200" /></a><br /><br />I emptied them onto a paper grocery bag to dry:<br /><br /><br />After examining them for a bit, and comping to the conclusion that the problem had been a overabundance of oxygen, I decided the next step was to put the oxides back into the forge, heat it up, and do my best to make sure that the fire was hot enough to reduce the oxide, and make sure that there was a dearth of oxygen in the containers.<br /><br />Side note: The Revol ceramics unsurprisingly didn't hold up. Apparently it was too hot for them: the glaze on one cracked, and the other actually broke in the fire, presumably from exceeding its design parameters by 800-900 degrees. :) <br /><br /><br />Onward to smelt #3!<br /><div class="separator" style="clear: both; text-align: center;"></div><div class="separator" style="clear: both; text-align: center;"></div>Unknownnoreply@blogger.com0tag:blogger.com,1999:blog-4959692416650249872.post-61523866676179240622010-04-11T00:46:00.000-07:002013-04-23T09:57:08.258-07:00Past efforts: Crucible neededWhen I got no obvious copper from the first smelt, I decided it would be a good idea to get something more stable in which to hold the ore while it was in the coals. Obviously, this would be a high-temperature reactive environment, so regular glass or metal cooking stuff might not cut it.<br /><br /><div class="separator" style="clear: both; text-align: center;"></div>My first stop was at Doit Center, where I found some very small terracotta flower pot saucers about 3" across and 1/2" deep. For 89 cents, they'd be my first try. Then I went <i>far</i> upscale, a specialty store called Sur La Table, which has all kinds of interesting kitchenware, including small cast-iron serving dishes and a kind of ceramicware called Revol which claims on its website to have a silica glaze and be fired in the 1300C range. I bought two of the cast-iron servers, and two small ramekins from Revol. There was also a marble mortar-and-pestle that was calling to me from the corner of the store, begging to be brought home. What was I supposed to do, ignore it?<br /><br />Here's the jazz I got:<br /><br /><br /><div class="separator" style="clear: both; text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjPxxuYCQ5pc5J2v1ss6MhutGlxL__5XBwMXf2pkr3pfE0Bb16B1vPCvbc_ptshkuzN6Qr3wfaW6TcSc0W6iyNev4T18WdjksuiRaivOBL0If_gTa6nQ38-4I3h8sJCBMjTHLGFmnKlx3g/s1600/SmeltingMalachite+006.JPG" imageanchor="1" style="margin-left: 1em; margin-right: 1em;"><img border="0" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjPxxuYCQ5pc5J2v1ss6MhutGlxL__5XBwMXf2pkr3pfE0Bb16B1vPCvbc_ptshkuzN6Qr3wfaW6TcSc0W6iyNev4T18WdjksuiRaivOBL0If_gTa6nQ38-4I3h8sJCBMjTHLGFmnKlx3g/s320/SmeltingMalachite+006.JPG" /></a><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEiY07ag4KlbjdOTDVXUYg-cXZg4XkBIeBdbi1q4GpQCALJpn9t455LV-_tdd0BIGyxcjV3umxUCmADcJXjG1RV4Jo_htUkZupziCxWyuc7CZ_n2yBCQ8uHyYVs2TrRwYYOqn6QfbbfjUiA/s1600/SmeltingMalachite+007.JPG" imageanchor="1" style="margin-left: 1em; margin-right: 1em;"><img border="0" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEiY07ag4KlbjdOTDVXUYg-cXZg4XkBIeBdbi1q4GpQCALJpn9t455LV-_tdd0BIGyxcjV3umxUCmADcJXjG1RV4Jo_htUkZupziCxWyuc7CZ_n2yBCQ8uHyYVs2TrRwYYOqn6QfbbfjUiA/s320/SmeltingMalachite+007.JPG" /></a><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEg6FZQ1MsCq8W7pZuKJqCWVd6omWGew3nlGDRhqv9iIzKOoS7DA9NzLGqJ6yhDkzd0c4B8lM3FdVIJ-qhsugVFDdC04J1KF4mGUmuV61zxjySSdMOhRLd-dno8FLKsUIHACvQggYGcWruo/s1600/SmeltingMalachite+008.JPG" imageanchor="1" style="margin-left: 1em; margin-right: 1em;"><img border="0" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEg6FZQ1MsCq8W7pZuKJqCWVd6omWGew3nlGDRhqv9iIzKOoS7DA9NzLGqJ6yhDkzd0c4B8lM3FdVIJ-qhsugVFDdC04J1KF4mGUmuV61zxjySSdMOhRLd-dno8FLKsUIHACvQggYGcWruo/s320/SmeltingMalachite+008.JPG" /></a><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjjLf1r7se4YHS8IvsnXG622ctoygrDgCoqJp53K39hy_LGdpNd8oqqPitPcthb4LD557ECXzIiIwLGVmtjB2xfOQvHs_LzDrl4Q9kC_WZ2H08LOhDs9PjnusXtXLduPIldRk8ikkHqNw0/s1600/SmeltingMalachite+009.JPG" imageanchor="1" style="margin-left: 1em; margin-right: 1em;"><img border="0" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjjLf1r7se4YHS8IvsnXG622ctoygrDgCoqJp53K39hy_LGdpNd8oqqPitPcthb4LD557ECXzIiIwLGVmtjB2xfOQvHs_LzDrl4Q9kC_WZ2H08LOhDs9PjnusXtXLduPIldRk8ikkHqNw0/s320/SmeltingMalachite+009.JPG" /></a></div>Unknownnoreply@blogger.com0