Marko Posted March 14, 2015 Report Share Posted March 14, 2015 I am out of G-200, what can I substitute? This is for Bright Sky Blue recipe by John H. and Ron R. Mastering ^6 5000 g batch EPK 1000 Feldspar G-300 1000 Talc 575 Frit 3134 1000 Silica 325 925 Wallastonite 500 Cobalt Carb 50 Red Iron 25 Rutile 300 Link to comment Share on other sites More sharing options...
bciskepottery Posted March 14, 2015 Report Share Posted March 14, 2015 G-200 and its replacement, G-200HP, are no longer available. You can do a blend of Minspar 200 (soda spar) and Custer (potash spar). http://www.clayworkssupplies.com/tech-info/ti_file1234374884.pdf https://www.highwaterclays.com/index.cfm?fuseaction=feature.display&feature_ID=306 Link to comment Share on other sites More sharing options...
Marko Posted March 14, 2015 Author Report Share Posted March 14, 2015 G-200 and its replacement, G-200HP, are no longer available. You can do a blend of Minspar 200 (soda spar) and Custer (potash spar). http://www.clayworkssupplies.com/tech-info/ti_file1234374884.pdf https://www.highwaterclays.com/index.cfm?fuseaction=feature.display&feature_ID=306 Wow, thanks bciskepottery. I will try the custer. I do a test batch before I commit to my 5000g batch I have already waiting this final element. Thanks for the PDF's I'll keep them in my glaze records binder. Link to comment Share on other sites More sharing options...
bciskepottery Posted March 14, 2015 Report Share Posted March 14, 2015 John Hesselberth has posted reformulations of the MC6G recipes . . . due to discontinuance of G-200 and change in Talc. http://www.masteringglazes.com/mastering-cone-6-glazes/glaze-reformulations/ Bright Sky Blue is Glossy Base #1. One of my favorites. Link to comment Share on other sites More sharing options...
David Woodin Posted March 14, 2015 Report Share Posted March 14, 2015 This is the same formula using Custer: Ferro 3134 999 Custer 1048 EPK 1010 Talc 586 Wollastonite 510 Silica 848 Total 5001 grams David Link to comment Share on other sites More sharing options...
Dick White Posted March 14, 2015 Report Share Posted March 14, 2015 Well, actually, Marko, Bruce, and David, there is another wrinkle. The G200 mine ran out a long time ago. It was replaced by G200HP (higher in potash), but a comparable material could be created by blending 70% G200HP and 30% Minspar. But then the G200HP mine ran out last year. So cancel that idea. At the time, the old G200 was very close to Custer, so some people just used Custer instead. However, a few years ago, the Custer product changed significantly. Pacer (the producer of Custer) denies there was any change, but potters noticed their glazes were not working properly and independent lab tests revealed that any Custer in the last 2-3 years is lower in potash and higher in silica, thus causing glazes with significant proportions of Custer to underfire. Ron Roy has written about this, and John H. has reformulated some of the glazes in their book. Here is a link to the revised Glossy Base 1 recipe using the new, lower potash Custer: http://www.masteringglazes.com/mastering-cone-6-glazes/glaze-reformulations/chapter-6-glaze-reformulati/glossy-base-1-new-custer.html Link to comment Share on other sites More sharing options...
Mark C. Posted March 14, 2015 Report Share Posted March 14, 2015 Well, actually, Marko, Bruce, and David, there is another wrinkle. The G200 mine ran out a long time ago. It was replaced by G200HP (higher in potash), but a comparable material could be created by blending 70% G200HP and 30% Minspar. But then the G200HP mine ran out last year. So cancel that idea. At the time, the old G200 was very close to Custer, so some people just used Custer instead. However, a few years ago, the Custer product changed significantly. Pacer (the producer of Custer) denies there was any change, but potters noticed their glazes were not working properly and independent lab tests revealed that any Custer in the last 2-3 years is lower in potash and higher in silica, thus causing glazes with significant proportions of Custer to underfire. Ron Roy has written about this, and John H. has reformulated some of the glazes in their book. Here is a link to the revised Glossy Base 1 recipe using the new, lower potash Custer: http://www.masteringglazes.com/mastering-cone-6-glazes/glaze-reformulations/chapter-6-glaze-reformulati/glossy-base-1-new-custer.html Dick nailed it as custer did change a few years back. One way to fix these changes is buy a large quantity of whatever material you use -then these changes do not affect you.I'm still working with 3,000#s of Kingman potash feldspar I bought in 1981. Mark Link to comment Share on other sites More sharing options...
Wyndham Posted March 14, 2015 Report Share Posted March 14, 2015 The new g200 eu comes from Spain, I believe. In my cone 10 r Temmoku and other glazes, I need a a bit more flux, still trying to dial it in. Wyndham Link to comment Share on other sites More sharing options...
Marko Posted March 14, 2015 Author Report Share Posted March 14, 2015 Holly Molly guys, this is more an answer than I expected, but I am so grateful. I am really green when it comes to glaze mixing. I wouldn't have know these things if you good people didn't help me. It's a lot to look at but It's what I want if I ever expect to really understand ^6 glazes. Hell, pottery for that matter. I join DigitalFire, but I can't understand it enough to make good practical use of it. I guess I should query Tony or you folk on some questions about it. I'm sure I can learn it, I just need to commit more time to it. I do have custer, but no minspar. My supplier, www.clayworld.com does not seems to have it. Is there a substitute for this also, or is it under a different name? My supplier has G200HP, so I got a 50# bag. In this recipe I show, I have already put everything in the 5gal bucket before I realized I did not have any G200. Can I just add the G200HP. I don't want to throw out all the chemical I already added. I guess I should have checked that I did indeed have enough. What can I say, just a newby. Link to comment Share on other sites More sharing options...
David Woodin Posted March 15, 2015 Report Share Posted March 15, 2015 Hi Mark, All you need to do is add 990 grams of G200 HP to the batch and 10 grams more of EPK.. The new 5K batch is as follows: Ferro 3134 1000 G 200 HP 990 EPK 1010 Talc 575 Wollastonite 500 Silica 925 David Link to comment Share on other sites More sharing options...
Marko Posted March 15, 2015 Author Report Share Posted March 15, 2015 Hi Mark, All you need to do is add 990 grams of G200 HP to the batch and 10 grams more of EPK.. The new 5K batch is as follows: Ferro 3134 1000 G 200 HP 990 EPK 1010 Talc 575 Wollastonite 500 Silica 925 David Thank you David, you are my hero. I really appreciate it. I do not know how you figure these things out, but I'm glad you are so kind and generous. I'm also glad I waited for an answer. And I promise I will try and learn this stuff better and make sure I test and have enough to make a bucket. Thanks again David. I will sleep better tonight and get this done tomorrow. Link to comment Share on other sites More sharing options...
Marko Posted March 15, 2015 Author Report Share Posted March 15, 2015 This is the same formula using Custer: Ferro 3134 999 Custer 1048 EPK 1010 Talc 586 Wollastonite 510 Silica 848 Total 5001 grams David Thanks for this one. I will keep it since, as I understand, G200HP might run out. Thumbs up! Link to comment Share on other sites More sharing options...
Marko Posted March 15, 2015 Author Report Share Posted March 15, 2015 I just want to thank you all for your help. I hope someday someone will ask me for help and I will know what to say. Thumbs up to everyone. Link to comment Share on other sites More sharing options...
David Woodin Posted March 15, 2015 Report Share Posted March 15, 2015 Hi Mark, Because of changes in Custer the following should be considered but I would test with 100 gram batches first. Ron Roy average Custer Insight Custer G200HP Ferro 3134 1000 1000 1000 Custer Ave 1235 1050 G200HP 990 EPK 990 1010 1010 Talc 575 575 575 Wollastonite 510 510 500 Silica 690 855 925 Good luck David Link to comment Share on other sites More sharing options...
Marko Posted March 16, 2015 Author Report Share Posted March 16, 2015 Hi Mark, Because of changes in Custer the following should be considered but I would test with 100 gram batches first. Ron Roy average Custer Insight Custer G200HP Ferro 3134 1000 1000 1000 Custer Ave 1235 1050 G200HP 990 EPK 990 1010 1010 Talc 575 575 575 Wollastonite 510 510 500 Silica 690 855 925 Good luck David Thanks for all your help, David. Now I hope I get it right. LOL Link to comment Share on other sites More sharing options...
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