icherem Posted September 6 Report Share Posted September 6 Hello! I tried to replicate a version of a recipe I found on Mastering Cone 6 Glazes, and although I got a result that I'm happy with, I was wondering if anyone has any advice on how to get it closer to the original. I've added pictures of my test tile (Laguna B mix fired to cone 6) as well as the intended result from the book. Thank you in advance for any advice! The recipe is this: Minspar 200 -- 23% Frit-Ferro3134 -- 20% Wollastonite -- 15.5% Kaolin-EPK -- 18.5% Talc -- 6% Silica --17% ----- Cobalt carbonate -- 1% Copper carbonate -- .75% Red iron oxide -- 3% Rutile -- 6% Quote Link to comment Share on other sites More sharing options...
PeterH Posted September 6 Report Share Posted September 6 You might find this page of interest. http://masteringglazes.com/mastering-cone-6-glazes/frequently-asked-questions.html It examines the effect of cooling one of the mastering cone 6 glazes at different speeds. http://masteringglazes.com/_Media/slowcoolingseries_med.jpeg Rae Reich 1 Quote Link to comment Share on other sites More sharing options...
icherem Posted September 6 Author Report Share Posted September 6 31 minutes ago, PeterH said: You might find this page of interest. http://masteringglazes.com/mastering-cone-6-glazes/frequently-asked-questions.html It examines the effect of cooling one of the mastering cone 6 glazes at different speeds. http://masteringglazes.com/_Media/slowcoolingseries_med.jpeg Thank you for the response that's very useful! The difference is so dramatic. Quote Link to comment Share on other sites More sharing options...
PeterH Posted September 7 Report Share Posted September 7 A couple more references on slow-cooling (which only has an effect if there is crystal growth during cooling). https://ceramicartsnetwork.org/daily/article/Super-Cool-Slow-Cooling-in-an-Electric-Kiln https://cone6pots.ning.com/forum/topics/slow-cooling icherem 1 Quote Link to comment Share on other sites More sharing options...
Dick White Posted September 7 Report Share Posted September 7 Several things to note here: The picture of the porcelain sake jar is from page 94 of the book, showing Glossy Base 1 with colorants, named Variegated Blue. Page 32 in the book shows a tan stoneware mug with the same glaze, and the outcome is similar to your test tile. The clay body can have a significant effect of the color of the glaze. The several recipes in the published book which use a feldspar all use either G200 or Custer, both of which are potash feldspars (and both of which are no longer available in the market). Subsequent to the book's publication, there were some significant changes to the availability and content of G200, Custer, and talc. In response to these materials changes, John and Ron developed modifications and alterations to several of the base recipes that were intended to be similar to originals, and published them on the masteringglazes website. The base recipe revisions were not tested with colorants. You have the altered Glossy Base 1 using Minspar, a soda feldspar, instead of the original G200. When comparing the UMF of the original recipe with the altered recipe, the alumina, silica, and boron levels are very close, but the flip to Minspar and the changed amounts of wollastonite and talc in the new recipe result in a different flux calculation. How much of an effect that has on the color response is unknown without side by side comparison testing with both the original and altered recipes. PeterH, Rae Reich, icherem and 1 other 4 Quote Link to comment Share on other sites More sharing options...
Hulk Posted September 7 Report Share Posted September 7 Curious, anyone getting the masteringglazes pages to load? I'm getting "404" error Quote Link to comment Share on other sites More sharing options...
PeterH Posted September 7 Report Share Posted September 7 14 minutes ago, Hulk said: Curious, anyone getting the masteringglazes pages to load? I'm getting "404" error Interesting, I tried reloading and it still works for me. http://masteringglazes.com/mastering-cone-6-glazes/frequently-asked-questions.html PS Happy to send you the pdf if you pm me your email address. Quote Link to comment Share on other sites More sharing options...
Hulk Posted September 7 Report Share Posted September 7 (edited) Thanks Peter! Another Forum regular messaged that the link is not secure, aha! ...and so I'm able to load the page(s) by removing the "s" in https:// I hadn't noticed the browser is inserting the S! Edited September 7 by Hulk actual issue, inserted "secure" letter https:// Rae Reich and PeterH 2 Quote Link to comment Share on other sites More sharing options...
icherem Posted September 7 Author Report Share Posted September 7 Thanks for the response Dick! Yes, I had to use a different base to be able to substitute for the G200, and I suspect that must have had some impact on the final result. I'm going to keep experimenting to hopefully be able to achieve that beautiful light green. Rae Reich 1 Quote Link to comment Share on other sites More sharing options...
Dick White Posted September 10 Report Share Posted September 10 On 9/7/2024 at 12:56 PM, icherem said: I'm going to keep experimenting to hopefully be able to achieve that beautiful light green. Cobalt, which is normally blue, shifts to green when in the presence of a fair amount of titanium and alumina. The rutile is providing the titanium, and the porcelain instead of stoneware may allow alumina a bit more freedom to shift the cobalt towards green. Quote Link to comment Share on other sites More sharing options...
icherem Posted Wednesday at 07:40 PM Author Report Share Posted Wednesday at 07:40 PM On 9/10/2024 at 5:26 PM, Dick White said: The rutile is providing the titanium, and the porcelain instead of stoneware may allow alumina a bit more freedom to shift the cobalt towards green. That's very interesting. Would you recommend maybe addding alumina to the recipe when done on stoneware? Thanks again for your help Quote Link to comment Share on other sites More sharing options...
Dick White Posted Wednesday at 09:15 PM Report Share Posted Wednesday at 09:15 PM I would not recommend adding plain alumina (typically available as alumina hydrate, but also can be obtained as alumina oxide) as it will change the melting behavior of the glaze. A better source of alumina is clay, but now you need to be facile with glaze calculation software. The amount of EPK in the recipe is approaching the max that one would want before it begins to crawl. The solution to crawling from excessive EPK is substituting calcined EPK for a portion of the initial amount of EPK, but that's not a 1:1 direct substitution. Again, glaze calculation software is your friend. However, all that said, you will only know after testing. Bill Kielb 1 Quote Link to comment Share on other sites More sharing options...
Babs Posted Wednesday at 10:13 PM Report Share Posted Wednesday at 10:13 PM Maybe dipping e test tile at leatherhard stage into a dwfloc porcelainous slip could give an idea what the glaze does on porcelain instead of stoneware? Quote Link to comment Share on other sites More sharing options...
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