Non plastic CLAY - Electric Mid&Hi Fired Ceramics2024-03-29T11:10:53Zhttps://cone6pots.ning.com/forum/topics/non-plastic-clay?commentId=2103784%3AComment%3A136861&feed=yes&xn_auth=noI use a 50/50 mix of kyanite…tag:cone6pots.ning.com,2016-08-16:2103784:Comment:1367682016-08-16T07:04:42.572ZNorm Stuarthttps://cone6pots.ning.com/profile/NormStuart
<p>I use a 50/50 mix of kyanite and wollastonite as the dry component of our studio's "Bisque-Fix", then adding a little sodium silicate and water just before use.</p>
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<p>Digitalfire says pyrophyllite promotes the formation of mullite. I personally have no idea what might promote the formation of kyanite. As Kyanite is a mined product rather than manufactured it probably can't be made inexpensively. Digitalfire refers to a decomposed mullite form of kyanite which is volume stable upon…</p>
<p>I use a 50/50 mix of kyanite and wollastonite as the dry component of our studio's "Bisque-Fix", then adding a little sodium silicate and water just before use.</p>
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<p>Digitalfire says pyrophyllite promotes the formation of mullite. I personally have no idea what might promote the formation of kyanite. As Kyanite is a mined product rather than manufactured it probably can't be made inexpensively. Digitalfire refers to a decomposed mullite form of kyanite which is volume stable upon heating - as well as "raw kyanite" which expands upon heating as with pyrophyllite. Perhaps Ron Roy could explain what the difference is.</p>
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<p><a rel="nofollow" href="https://digitalfire.com/4sight/material/kyanite_951.html" target="_blank">https://digitalfire.com/4sight/material/kyanite_951.html</a></p>
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<p>It certainly makes sense to me to use Kyanite in place of the Fireclay in each of the above recipes as Kyanite is a refractory, but one which actually makes the clay body more plastic as well as adding body and tooth like the fireclay does.</p>
<p></p> Norm:
Has anyone considered u…tag:cone6pots.ning.com,2016-08-16:2103784:Comment:1366582016-08-16T02:41:58.327ZTom Andersonhttps://cone6pots.ning.com/profile/TomAnderson
<p>Norm:</p>
<p>Has anyone considered using kyanite in flameware? Likewise it produces elongated strands of mullite. Ron Roy and I have had a lengthy converstion about the benefits of kyanite verses grog (mullite). Would like to hear your insights on this.</p>
<p>Tom Anderson</p>
<p>Norm:</p>
<p>Has anyone considered using kyanite in flameware? Likewise it produces elongated strands of mullite. Ron Roy and I have had a lengthy converstion about the benefits of kyanite verses grog (mullite). Would like to hear your insights on this.</p>
<p>Tom Anderson</p> Flameware, pots which can be…tag:cone6pots.ning.com,2016-08-15:2103784:Comment:1366572016-08-15T21:17:57.156ZNorm Stuarthttps://cone6pots.ning.com/profile/NormStuart
<p>Flameware, pots which can be used over an open fire, requires a clay body with extremely low heat-expansion, which is difficult to achieve, and will shiver off any conventional glaze.</p>
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<p>Both the cay body and the glaze/engobe need to consist of low-epansion lithium flux without any high expansion fluxes like sodium. This lack of sodium is so important that the clay has to be hydrated with distilled water.</p>
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<p>Lithium based clays use at least 30% spodumene with just…</p>
<p>Flameware, pots which can be used over an open fire, requires a clay body with extremely low heat-expansion, which is difficult to achieve, and will shiver off any conventional glaze.</p>
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<p>Both the cay body and the glaze/engobe need to consist of low-epansion lithium flux without any high expansion fluxes like sodium. This lack of sodium is so important that the clay has to be hydrated with distilled water.</p>
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<p>Lithium based clays use at least 30% spodumene with just enough calcium or magnesium bentonite, about 3%, to provide plasticity. Even with this level of bentonite, flameware clay lacks plasticity as enough bentonite increases the COE of the clay too much.</p>
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<p>It's my belief that the primary reason for the addition of 10% Pyrophyllite is this promotes the formation of kaolin into mullite, used in chemistry crucibles. Mullite has a structure of long interlocking needles which helps prevent thermal cracking.</p>
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<p><a rel="nofollow" href="https://digitalfire.com/4sight/material/pyrophyllite_1167.html" target="_blank">https://digitalfire.com/4sight/material/pyrophyllite_1167.html</a></p>
<p><a rel="nofollow" href="https://digitalfire.com/4sight/material/mullite_1054.html" target="_blank">https://digitalfire.com/4sight/material/mullite_1054.html</a></p>
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<p>Most potters successfully making flameware have their own recipe which they <strong>don't share</strong>. The key to developing your own flameware body is sending out fired samples to a lab or potter who has a dilatometer which can measure the COE of each of your attempts at making a flameware clay.</p>
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<p>My own attempts to make a Cone 6 flameware relied heavily on the addition of lithium carbonate to flux these Cone 9 formulas down and the use of VeeGum bentonite which also acts as a powerful flux in addition to being a plasticizer.</p>
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<p>These are two sample flameware clays which have been shared publicly. Small differences in ingredients can make huge changes in the fired COE of the clay body.</p>
<table border="0" cellspacing="0" width="508">
<colgroup><col width="78"></col><col width="75"></col><col width="355"></col></colgroup><tbody><tr><td class="xl67" colspan="3" height="25" width="508"></td>
</tr>
<tr><td class="xl72" align="right" height="25">500.0</td>
<td class="xl70" align="right">103.0% </td>
<td class="xl68"><strong>Ron Propst's ^9 Flameware Formula</strong></td>
</tr>
<tr><td class="xl69" align="right" height="25">150</td>
<td class="xl70" align="right">30.0%</td>
<td class="xl71"> Spodumene (200 mesh)</td>
</tr>
<tr><td class="xl69" align="right" height="25">50</td>
<td class="xl70" align="right">10.0%</td>
<td class="xl71"> Pyrophyllite (200 mesh)</td>
</tr>
<tr><td class="xl69" align="right" height="25">50</td>
<td class="xl70" align="right">10.0%</td>
<td class="xl71"> Feldspar Custer Potash</td>
</tr>
<tr><td class="xl69" align="right" height="25">100</td>
<td class="xl70" align="right">20.0%</td>
<td class="xl71"> Ball Clay OM4</td>
</tr>
<tr><td class="xl69" align="right" height="25">150</td>
<td class="xl70" align="right">30.0%</td>
<td class="xl71"> A.P. Green Fireclay</td>
</tr>
<tr><td class="xl69" align="right" height="25">10</td>
<td class="xl70" align="right">2.0%</td>
<td class="xl71"> Bentonite</td>
</tr>
<tr><td class="xl69" align="right" height="25">5</td>
<td class="xl70" align="right">1.0%</td>
<td class="xl71"> Macaloid</td>
</tr>
<tr><td height="25"></td>
<td></td>
<td></td>
</tr>
<tr><td class="xl67" colspan="3" height="25"><a rel="nofollow" href="http://ceramicartsdaily.org/ceramic-art-and-artists/functional-pottery/cooking-with-clay-for-slow-food-and-a-healthy-world/" target="_blank">http://ceramicartsdaily.org/ceramic-art-and-artists/functional-pott...</a></td>
</tr>
<tr><td class="xl72" align="right" height="25">500.0</td>
<td class="xl70" align="right">105.0%</td>
<td class="xl68"> <strong>Robbie Lobell's ^9 Flameware Formula</strong></td>
</tr>
<tr><td class="xl69" align="right" height="25">150</td>
<td class="xl70" align="right">30.0%</td>
<td class="xl71"> Spodumene (200 mesh)</td>
</tr>
<tr><td class="xl69" align="right" height="25">50</td>
<td class="xl70" align="right">10.0%</td>
<td class="xl71"> Pyrophyllite (200 mesh)</td>
</tr>
<tr><td class="xl69" align="right" height="25">50</td>
<td class="xl70" align="right">10.0%</td>
<td class="xl71"> Feldspar Custer Potash</td>
</tr>
<tr><td class="xl69" align="right" height="25">125</td>
<td class="xl70" align="right">25.0%</td>
<td class="xl71"> Ball Clay OM4</td>
</tr>
<tr><td class="xl69" align="right" height="25">125</td>
<td class="xl70" align="right">25.0%</td>
<td class="xl71"> A.P. Green Fireclay</td>
</tr>
<tr><td class="xl69" align="right" height="25">25</td>
<td class="xl70" align="right">5.0%</td>
<td class="xl71"> Grog 48 mesh</td>
</tr>
</tbody>
</table> It's me replying very late th…tag:cone6pots.ning.com,2016-08-15:2103784:Comment:1368612016-08-15T18:26:33.022ZMarithou dupouxhttps://cone6pots.ning.com/profile/Marithoudupoux
It's me replying very late the bentonite worked well thanks,<br/>
As I need more help,now I would like to use that clay for flameware do I put talc and pyrophylite in it to have it @ cone 6 ,?<br />
my kiln doesn't go farther than cone 6 this clay does Raku very well as I mixed it up with basaltic sand.<br/>
Thanks for the help
It's me replying very late the bentonite worked well thanks,<br/>
As I need more help,now I would like to use that clay for flameware do I put talc and pyrophylite in it to have it @ cone 6 ,?<br />
my kiln doesn't go farther than cone 6 this clay does Raku very well as I mixed it up with basaltic sand.<br/>
Thanks for the help Thank for the suggestion I wi…tag:cone6pots.ning.com,2013-08-03:2103784:Comment:871762013-08-03T00:58:12.217ZMarithou dupouxhttps://cone6pots.ning.com/profile/Marithoudupoux
Thank for the suggestion I will try it as soon as possible,and will keep you posted
Thank for the suggestion I will try it as soon as possible,and will keep you posted Add 5% Bentonite, by weight,…tag:cone6pots.ning.com,2013-08-02:2103784:Comment:872632013-08-02T20:06:01.906ZNorm Stuarthttps://cone6pots.ning.com/profile/NormStuart
<p>Add 5% Bentonite, by weight, to your dry non-plastic clay. Bentonite is the most plastic clay.</p>
<p><a href="http://www.axner.com/bentonite-325mesh.aspx" target="_blank">http://www.axner.com/bentonite-325mesh.aspx</a></p>
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<p>Bentonite is added to non-plastic English Grolleg Kaolin to make it into a workable clay body.</p>
<p><a href="http://www.axner.com/bentonite-325mesh.aspx" target="_blank">http://digitalfire.com/4sight/material/grolleg_kaolin_831.html</a></p>
<p></p>
<p>This is…</p>
<p>Add 5% Bentonite, by weight, to your dry non-plastic clay. Bentonite is the most plastic clay.</p>
<p><a href="http://www.axner.com/bentonite-325mesh.aspx" target="_blank">http://www.axner.com/bentonite-325mesh.aspx</a></p>
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<p>Bentonite is added to non-plastic English Grolleg Kaolin to make it into a workable clay body.</p>
<p><a href="http://www.axner.com/bentonite-325mesh.aspx" target="_blank">http://digitalfire.com/4sight/material/grolleg_kaolin_831.html</a></p>
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<p>This is a more costly white bentonite.</p>
<p><a href="http://www.axner.com/bentonite-vee-gum-t.aspx" target="_blank">http://www.axner.com/bentonite-vee-gum-t.aspx</a></p>
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<p>You may find Linda Arbuckle's paper on clay bodies helpful.</p>
<p><a href="http://lindaarbuckle.com/handouts/clays-and-clay-bodies.pdf" target="_blank">http://lindaarbuckle.com/handouts/clays-and-clay-bodies.pdf</a></p>
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<p>Let me know how bentonite works for you. You may need to add less than 5% or even more than 5%.</p>
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<p>Marithou - I love your acrylic paintings, especially "at night".</p>
<p><a href="http://www.absolutearts.com/cgi-bin/portfolio/art/your-art.cgi?login=maritou&title=at_night-1193799834t.jpg" target="_blank">http://www.absolutearts.com/cgi-bin/portfolio/art/your-art.cgi?logi...</a></p>