Can one predict the appearance of a glaze? (part I: The Si/Al ratio) - Electric Mid&Hi Fired Ceramics2024-03-28T13:37:08Zhttps://cone6pots.ning.com/forum/topics/can-one-predict-the-appearance-of-a-glaze-part-i-the-si-al-ratio?commentId=2103784%3AComment%3A137643&x=1&feed=yes&xn_auth=noOne thing I've realised recen…tag:cone6pots.ning.com,2016-10-19:2103784:Comment:1376432016-10-19T22:50:56.769ZTom Humphrieshttps://cone6pots.ning.com/profile/TomHumphries
One thing I've realised recently is the power of colourants. I made a base glaze recently that I had tailored the si/al ratio to produced my desired level of shine. Adding 5% copper oxide made a drastic difference on the gloss level.
One thing I've realised recently is the power of colourants. I made a base glaze recently that I had tailored the si/al ratio to produced my desired level of shine. Adding 5% copper oxide made a drastic difference on the gloss level. Obviously, it is better to us…tag:cone6pots.ning.com,2016-08-19:2103784:Comment:1368812016-08-19T07:37:31.961ZDaniel Spruythttps://cone6pots.ning.com/profile/DanielSpruyt
<p>Obviously, it is better to use high purity ingredients if the price doesn't matter. I can imagine that it is even more the case for crystalline glazes. The only high purity ingredient I have is a batch of 5 kg CaCO3 laboratory grade because I had the opportunity to get it for free. It also appears that some suppliers are not consistent in the quality they provide.</p>
<p>I have no experience for the compounds you mention, they are probably American. I operate in Belgium.</p>
<p>Obviously, it is better to use high purity ingredients if the price doesn't matter. I can imagine that it is even more the case for crystalline glazes. The only high purity ingredient I have is a batch of 5 kg CaCO3 laboratory grade because I had the opportunity to get it for free. It also appears that some suppliers are not consistent in the quality they provide.</p>
<p>I have no experience for the compounds you mention, they are probably American. I operate in Belgium.</p> Daniel:
Have you done any exp…tag:cone6pots.ning.com,2016-08-18:2103784:Comment:1369562016-08-18T21:38:14.306ZTom Andersonhttps://cone6pots.ning.com/profile/TomAnderson
<p>Daniel:</p>
<p>Have you done any experimenting with high purity ingredients? Case in point: Imsil A-25 silica, XL500 french process zinc, or Minex 400 Nep Sy? I do crystalline glazes mostly, anything and everything effects outcome. However, I do mostly c6 oxidation firings, and have noticed great improvements in melt, opacity, and color by using high purity recipes.</p>
<p>Tom Anderson</p>
<p>Daniel:</p>
<p>Have you done any experimenting with high purity ingredients? Case in point: Imsil A-25 silica, XL500 french process zinc, or Minex 400 Nep Sy? I do crystalline glazes mostly, anything and everything effects outcome. However, I do mostly c6 oxidation firings, and have noticed great improvements in melt, opacity, and color by using high purity recipes.</p>
<p>Tom Anderson</p> Hi Tom,
Indeed Si/Al ratios…tag:cone6pots.ning.com,2016-08-18:2103784:Comment:1368772016-08-18T07:40:41.739ZDaniel Spruythttps://cone6pots.ning.com/profile/DanielSpruyt
<p>Hi Tom,</p>
<p></p>
<p>Indeed Si/Al ratios are important. But, I think you can have enough parameters at reach when dealing with glazes. It is very complex and one parameter alone does not tell everything. For instance I keep track of Si/Al SiB/Al, Limits, thermal expansion... and still sometimes I have surprises.</p>
<p>Hi Tom,</p>
<p></p>
<p>Indeed Si/Al ratios are important. But, I think you can have enough parameters at reach when dealing with glazes. It is very complex and one parameter alone does not tell everything. For instance I keep track of Si/Al SiB/Al, Limits, thermal expansion... and still sometimes I have surprises.</p> HI Daniel, pleasure to meet y…tag:cone6pots.ning.com,2016-08-17:2103784:Comment:1368722016-08-17T22:28:57.640ZTom Andersonhttps://cone6pots.ning.com/profile/TomAnderson
<p>HI Daniel, pleasure to meet you sir.</p>
<p>When I seen the thread topic "Si/Al" ratios, I had to stop in for a look. Very much appreciate you posting testing information and data on this topic. I often catch heat from other potters because I preach Si/Al over seger unity. Not that I dismiss unity formulation, I just strongly believe Si/Al ratios are the heart of any glaze. Without this formula limit/s, you really do not have a glaze per se to begin with. IMO</p>
<p>Tom Anderson</p>
<p>HI Daniel, pleasure to meet you sir.</p>
<p>When I seen the thread topic "Si/Al" ratios, I had to stop in for a look. Very much appreciate you posting testing information and data on this topic. I often catch heat from other potters because I preach Si/Al over seger unity. Not that I dismiss unity formulation, I just strongly believe Si/Al ratios are the heart of any glaze. Without this formula limit/s, you really do not have a glaze per se to begin with. IMO</p>
<p>Tom Anderson</p> Thank you for the interest.…tag:cone6pots.ning.com,2014-05-11:2103784:Comment:1058472014-05-11T11:22:13.366ZDaniel Spruythttps://cone6pots.ning.com/profile/DanielSpruyt
<p>Thank you for the interest.<br/> <br/> <cite>Nadine Mercader said:</cite></p>
<blockquote cite="http://cone6pots.ning.com/forum/topics/can-one-predict-the-appearance-of-a-glaze-part-i-the-si-al-ratio?xg_source=activity#2103784Comment105327"><div><div class="xg_user_generated"><p>Thank you for taking the time to create this discussion, I will learn so much from you.</p>
<p></p>
</div>
</div>
</blockquote>
<p>Thank you for the interest.<br/> <br/> <cite>Nadine Mercader said:</cite></p>
<blockquote cite="http://cone6pots.ning.com/forum/topics/can-one-predict-the-appearance-of-a-glaze-part-i-the-si-al-ratio?xg_source=activity#2103784Comment105327"><div><div class="xg_user_generated"><p>Thank you for taking the time to create this discussion, I will learn so much from you.</p>
<p></p>
</div>
</div>
</blockquote> That is the range in which th…tag:cone6pots.ning.com,2014-05-11:2103784:Comment:1057502014-05-11T02:40:37.456ZDaniel Spruythttps://cone6pots.ning.com/profile/DanielSpruyt
<p>That is the range in which the glazes are glossy (best melt, close to eutectic)<br/> <br/> <cite>George Lewter said:</cite></p>
<blockquote cite="http://cone6pots.ning.com/forum/topics/can-one-predict-the-appearance-of-a-glaze-part-i-the-si-al-ratio?commentId=2103784%3AComment%3A105327&xg_source=msg_com_forum#2103784Comment105437"><div><div class="xg_user_generated"><p>Daniel, what is the long diagonal swath from lower left to middle right?</p>
</div>
</div>
</blockquote>
<p>That is the range in which the glazes are glossy (best melt, close to eutectic)<br/> <br/> <cite>George Lewter said:</cite></p>
<blockquote cite="http://cone6pots.ning.com/forum/topics/can-one-predict-the-appearance-of-a-glaze-part-i-the-si-al-ratio?commentId=2103784%3AComment%3A105327&xg_source=msg_com_forum#2103784Comment105437"><div><div class="xg_user_generated"><p>Daniel, what is the long diagonal swath from lower left to middle right?</p>
</div>
</div>
</blockquote> Daniel, what is the long diag…tag:cone6pots.ning.com,2014-05-10:2103784:Comment:1054372014-05-10T17:27:02.388ZGeorge Lewterhttps://cone6pots.ning.com/profile/GeorgeLewter
<p>Daniel, what is the long diagonal swath from lower left to middle right?</p>
<p>Daniel, what is the long diagonal swath from lower left to middle right?</p> Thank you for taking the time…tag:cone6pots.ning.com,2014-05-10:2103784:Comment:1053272014-05-10T15:49:42.129ZNadine Mercaderhttps://cone6pots.ning.com/profile/NadineMercader
<p>Thank you for taking the time to create this discussion, I will learn so much from you.</p>
<p></p>
<p>Thank you for taking the time to create this discussion, I will learn so much from you.</p>
<p></p>