SCM at cone 6. Glaze Issues, Firing Temp, and Chemistry Questions - Electric Mid&Hi Fired Ceramics2024-03-29T05:55:15Zhttps://cone6pots.ning.com/forum/topics/scm-at-cone-6-glaze-issues-firing-temp-and-chemistry-questions?groupUrl=sahillproject&commentId=2103784%3AComment%3A135185&groupId=2103784%3AGroup%3A2269&feed=yes&xn_auth=noThe underlying question is at…tag:cone6pots.ning.com,2016-07-25:2103784:Comment:1359632016-07-25T02:10:34.620ZNorm Stuarthttps://cone6pots.ning.com/profile/NormStuart
<p>The underlying question is at what Cone does strontium participate in the glaze, as carbonate or other form. This is prompted by the observation that Sctrontium Crystal Magic doesn't appear to do much to a glaze at an actual Cone 6. Many using SCM fire one or two cones hotter.<br></br> <br></br> <cite>Tom Anderson said:…</cite></p>
<p>The underlying question is at what Cone does strontium participate in the glaze, as carbonate or other form. This is prompted by the observation that Sctrontium Crystal Magic doesn't appear to do much to a glaze at an actual Cone 6. Many using SCM fire one or two cones hotter.<br/> <br/> <cite>Tom Anderson said:</cite></p>
<blockquote cite="http://cone6pots.ning.com/forum/topics/scm-at-cone-6-glaze-issues-firing-temp-and-chemistry-questions?groupUrl=sahillproject&commentId=2103784%3AComment%3A135956&xg_source=msg_com_gr_forum#2103784Comment135956"><div><p>Hi Joseph:</p>
<p>Have read through the posts regarding this topic. Looks like you are trying to alter the molecular structure of strontium through antistropic etching. I think in this particular case, KOH (potassium hydroxide) might be the better etchant, given the base molecule of silicon. Just happen to have a pound of silicon carbide and a few pounds of KOH out in the studio. I use this same technique on silica with good results. Give me a week or two to get results, and I will share them later. </p>
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<p>Tom</p>
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</blockquote> Hi Joseph:
Have read through…tag:cone6pots.ning.com,2016-07-24:2103784:Comment:1359562016-07-24T17:38:24.546ZTom Andersonhttps://cone6pots.ning.com/profile/TomAnderson
<p>Hi Joseph:</p>
<p>Have read through the posts regarding this topic. Looks like you are trying to alter the molecular structure of strontium through antistropic etching. I think in this particular case, KOH (potassium hydroxide) might be the better etchant, given the base molecule of silicon. Just happen to have a pound of silicon carbide and a few pounds of KOH out in the studio. I use this same technique on silica with good results. Give me a week or two to get results, and I will share…</p>
<p>Hi Joseph:</p>
<p>Have read through the posts regarding this topic. Looks like you are trying to alter the molecular structure of strontium through antistropic etching. I think in this particular case, KOH (potassium hydroxide) might be the better etchant, given the base molecule of silicon. Just happen to have a pound of silicon carbide and a few pounds of KOH out in the studio. I use this same technique on silica with good results. Give me a week or two to get results, and I will share them later. </p>
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<p>Tom</p> Also, does anyone have the co…tag:cone6pots.ning.com,2016-07-13:2103784:Comment:1351852016-07-13T00:58:16.047ZJoseph Firebornhttps://cone6pots.ning.com/profile/JosephRosenblatt
<p>Also, does anyone have the correct schedule for cone 6 SH firing schedule? I have read so many different ones online. Even the one in his video's from CAD are different from the ones in Britt's book. </p>
<p>Also, does anyone have the correct schedule for cone 6 SH firing schedule? I have read so many different ones online. Even the one in his video's from CAD are different from the ones in Britt's book. </p> Norm,
This explains a lot of…tag:cone6pots.ning.com,2016-07-13:2103784:Comment:1353592016-07-13T00:56:32.953ZJoseph Firebornhttps://cone6pots.ning.com/profile/JosephRosenblatt
<p>Norm, </p>
<p>This explains a lot of what I am experiencing. I have not had much success with SCM, almost always my surfaces have been super gritty and sandy feeling. So much so that I don't even enjoy touching the surfaces. I have tried thin layers of SCM as many have talked about, but then you don't get much out of it and the surface is very similar to the original glaze. </p>
<p>Has anyone ever ran a currie grid test on SCM? I think I am going to do that soon. I have some grids drying…</p>
<p>Norm, </p>
<p>This explains a lot of what I am experiencing. I have not had much success with SCM, almost always my surfaces have been super gritty and sandy feeling. So much so that I don't even enjoy touching the surfaces. I have tried thin layers of SCM as many have talked about, but then you don't get much out of it and the surface is very similar to the original glaze. </p>
<p>Has anyone ever ran a currie grid test on SCM? I think I am going to do that soon. I have some grids drying that I will put under a fan tomorrow before I bisque them. I will run this SCM currie test and post results. I bet in the lower left corners of the grid I will find a better version with more melt, because of a much higher flux content. I imagine a lot of the tiles will be very dry. </p>
<p></p> Theresa - I'm glad to get som…tag:cone6pots.ning.com,2016-07-12:2103784:Comment:1351032016-07-12T23:25:30.527ZNorm Stuarthttps://cone6pots.ning.com/profile/NormStuart
<p><a href="http://cone6pots.ning.com/xn/detail/u_027h5unajk1ti" target="_self">Theresa</a> - I'm glad to get some validation on these points regarding SCM and other allegedly Cone 6 glazes. I wasted a lot of hours five years ago trying to make some of these recipes work at Cone 6.</p>
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<p><em>I am finding that SCM and a few other glazes do not melt at the lower temp. My glazes don't look the same. I am going back to the beginning and will be testing some alterations. One thing I…</em></p>
<p><a href="http://cone6pots.ning.com/xn/detail/u_027h5unajk1ti" target="_self">Theresa</a> - I'm glad to get some validation on these points regarding SCM and other allegedly Cone 6 glazes. I wasted a lot of hours five years ago trying to make some of these recipes work at Cone 6.</p>
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<p><em>I am finding that SCM and a few other glazes do not melt at the lower temp. My glazes don't look the same. I am going back to the beginning and will be testing some alterations. One thing I wonder is, since Custer Feldspar changed a couple years ago whether it may be altering the glaze. - <a href="http://cone6pots.ning.com/xn/detail/2103784:Comment:135182?xg_source=activity" target="_blank">http://cone6pots.ning.com/xn/detail/2103784:Comment:135182?xg_sourc...</a></em></p>
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<p>Custer Feldspar by itself doesn't melt at Cone 6, even when it had more potassium years ago. I doubt anyone could notice a change in the degree of melt based on a change in feldspar, only a change in the final COE or gloss.</p>
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<p>This is what feldspars look like after being fired to <strong>Cone 11</strong>, about 130 degrees hotter than Cone 6. Only the high soda spar (Na - natrium) is showing any flow.</p>
<p><em>courtesy of Plainsman Clay via Digitalfire</em>.</p>
<p><a target="_self" href="http://storage.ning.com/topology/rest/1.0/file/get/3127174035?profile=original"><img width="721" class="align-left" src="http://storage.ning.com/topology/rest/1.0/file/get/3127174035?profile=RESIZE_1024x1024" width="721"/></a></p>
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<p>At Cone 6 feldspars are little more than clay, which do contribute salts equal to 10 to 14% of their weight, to the final melt.</p>
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<p>But without adding Frit, or a low temperature flux like a boron item like gerstley borate, zinc, lead or bismuth the feldspar won't melt at all.</p>
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<p><strong>Even with 10% frit, feldspars are only just starting to act like a glaze at Cone 8. </strong></p>
<p><a target="_self" href="http://storage.ning.com/topology/rest/1.0/file/get/3127175110?profile=original"><img width="721" class="align-left" src="http://storage.ning.com/topology/rest/1.0/file/get/3127175110?profile=RESIZE_1024x1024" width="721"/></a></p>
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<p>To make this mixture act like <strong>a Cone 6 glaze you'd need to increase the percentage of Frit to 20% to 26%</strong>.</p>
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