Raw glaze recipe - Electric Mid&Hi Fired Ceramics2024-03-29T14:10:34Zhttps://cone6pots.ning.com/forum/topics/raw-glaze-recipe?commentId=2103784%3AComment%3A148503&feed=yes&xn_auth=noTom:
Look at the glaze this w…tag:cone6pots.ning.com,2018-03-18:2103784:Comment:1485532018-03-18T00:43:50.087ZTom Andersonhttps://cone6pots.ning.com/profile/TomAnderson
<p>Tom:</p>
<p>Look at the glaze this way: a standard porcelain clay body is 50% kaolin, 25% silica! and 25% feldspar. Your glaze recipe has 32% clay content; the most I have seen prior to is 20%. If cone 6 glazes average 50% spar, I would guesstimate 40% minimum at cone 8. With that amount of clay content, it will need some added flux to melt it. 32% clay content will require more flux and heat! and will tolerate more flux and heat.</p>
<p>i looked up some info on Potclay's site in the UK.…</p>
<p>Tom:</p>
<p>Look at the glaze this way: a standard porcelain clay body is 50% kaolin, 25% silica! and 25% feldspar. Your glaze recipe has 32% clay content; the most I have seen prior to is 20%. If cone 6 glazes average 50% spar, I would guesstimate 40% minimum at cone 8. With that amount of clay content, it will need some added flux to melt it. 32% clay content will require more flux and heat! and will tolerate more flux and heat.</p>
<p>i looked up some info on Potclay's site in the UK. hVA/R 3408 has 27% alumina, 0.90% iron! and zero carbon content. You have pay closer attention to carbon content when using clay in a glaze. Carbon plays a role in pin- holing and bloating: so 0% carbon is well suited for a glaze recipe.</p>
<p>Tom</p> Thanks Tom, my local UK suppl…tag:cone6pots.ning.com,2018-03-17:2103784:Comment:1485522018-03-17T23:29:31.351ZTom Humphrieshttps://cone6pots.ning.com/profile/TomHumphries
<p>Thanks Tom, my local UK supplier only sells hp71 ball clay so I'm stuck with that for now. I guess I could reduce the quartz if alumina is too low? But I suppose that will result in Matt glaze. When your say right on border you mean only just melting and ^8 ? </p>
<p>Thanks Tom, my local UK supplier only sells hp71 ball clay so I'm stuck with that for now. I guess I could reduce the quartz if alumina is too low? But I suppose that will result in Matt glaze. When your say right on border you mean only just melting and ^8 ? </p> By the way, with that much ba…tag:cone6pots.ning.com,2018-03-17:2103784:Comment:1485032018-03-17T14:26:40.056ZTom Andersonhttps://cone6pots.ning.com/profile/TomAnderson
<p>By the way, with that much ball clay, bentonite for suspension should not be required.</p>
<p>By the way, with that much ball clay, bentonite for suspension should not be required.</p> Tom:
HP71 has 0.80% iron with…tag:cone6pots.ning.com,2018-03-17:2103784:Comment:1485462018-03-17T14:25:46.966ZTom Andersonhttps://cone6pots.ning.com/profile/TomAnderson
<p>Tom:</p>
<p>HP71 has 0.80% iron with 19% alumina. Old Hickory #5 has 0.88% iron! but nearly 30% alumina. Just as alumina gives glaze strength, it likewise does the same for clay. In short, #5 will make your glaze stronger and more resistant to cutlery marks. At cone 8, the 32% soda spar is probably right on the border for a melt; most cone 6 recipes typically have 50%. </p>
<p>Tom</p>
<p>Tom:</p>
<p>HP71 has 0.80% iron with 19% alumina. Old Hickory #5 has 0.88% iron! but nearly 30% alumina. Just as alumina gives glaze strength, it likewise does the same for clay. In short, #5 will make your glaze stronger and more resistant to cutlery marks. At cone 8, the 32% soda spar is probably right on the border for a melt; most cone 6 recipes typically have 50%. </p>
<p>Tom</p> I have some bentonite I could…tag:cone6pots.ning.com,2018-03-16:2103784:Comment:1483362018-03-16T22:40:58.159ZTom Humphrieshttps://cone6pots.ning.com/profile/TomHumphries
<p>I have some bentonite I could add if needed after a bit of testing</p>
<p>I have some bentonite I could add if needed after a bit of testing</p>