porcelainbyAntoinette Posted April 18, 2017 Report Share Posted April 18, 2017 Hi Guys. What is the latest changes on G 200 and or the HP? I saw some Spanish Feldspar somewhere at $3 per lb, which is way over what I would like to spend. I know Custer and the soda spars that is available, but before I make the final changes to some porcelain clay recipes, I would like to look at all the possible options. Thanks for any information. Antoinette TeachinArt.com PorcelainbyAntoinette Link to comment Share on other sites More sharing options...
glazenerd Posted April 18, 2017 Report Share Posted April 18, 2017 Mavahir runs less than $1 a lb. Link to comment Share on other sites More sharing options...
porcelainbyAntoinette Posted April 19, 2017 Author Report Share Posted April 19, 2017 Thank you Glazenerd. That was quick. I see the biggest differences is in the Calcium and the Magnesium. I wonder how much I should worry about that or if I must find something in addition to fill the deficiency up. Whiting maybe in small percentages, or dolomite that contain both calcium and magnesium. http://teachinart.com/index.html http://www.porcelainbyantoinette.com/index.html Link to comment Share on other sites More sharing options...
glazenerd Posted April 19, 2017 Report Share Posted April 19, 2017 It all depends what your goal is in porcelain. I keep the elemental metal oxides on the very low side. Bar 3 at the top has magnesium causing a grey hue. Bar 5 has higher levels of titanium. Calcium does make a good floc for porcelain, but you need very little to do the job. All my porcelain recipes have a straight 1% whiting addition. To keep the body high white, then elemental oxides must be kept very low. You can blend your fluxes as well: 50/50 Nep Sy & Mahavir if you like to balance the KNaO. High levels of sodium will cause it to dry a bit quicker, and high levels of potassium will off-gas more so than sodium. Happy Formulating- Nerd Link to comment Share on other sites More sharing options...
porcelainbyAntoinette Posted April 19, 2017 Author Report Share Posted April 19, 2017 Thanks. Just have to shake the gray matter in my brain around again. Just finished with a series of tests with the 200HP. It is frustrating when materials change so fast. I try to stay away from natrium based materials. Neph Sye is one of them. I prefer shorter clay over thixotropic clay. Will let you know if something comes of it. http://teachinart.com/index.html PorcelainbyAntoinette Link to comment Share on other sites More sharing options...
bciskepottery Posted April 20, 2017 Report Share Posted April 20, 2017 http://www.lagunaclay.com/support/pdf/mfelpf01_Mahavir_Feldspar.pdf Link to comment Share on other sites More sharing options...
Guest JBaymore Posted April 20, 2017 Report Share Posted April 20, 2017 I prefer shorter clay over thixotropic clay. Thixotropy in clay is a total no-go for me. I'd rather work with wet beach sand. best, ..................john Link to comment Share on other sites More sharing options...
glazenerd Posted April 20, 2017 Report Share Posted April 20, 2017 Thixotropy used in conjunction with clay body makes me smile. Another one of those pottery world expressions that I have yet to comprehend its use. Link to comment Share on other sites More sharing options...
Guest JBaymore Posted April 20, 2017 Report Share Posted April 20, 2017 Thixotropy used in conjunction with clay body makes me smile. Another one of those pottery world expressions that I have yet to comprehend its use. Get some poorly formulated cone 6 porcelain.......... throw with it with some added water.... don't keep anything........ put the pots and the throwing slop in a container.........let it sit a while.... reclaim it... and try to use it again on the wheel. best, ....................john Link to comment Share on other sites More sharing options...
porcelainbyAntoinette Posted April 20, 2017 Author Report Share Posted April 20, 2017 Also hard to carve. As the solubles settle to gel, nothing works until the particles get heated again. When I was teaching in Europe in 2016, someone gave me a piece of Mont Blanc porcelain. I managed to throw a small piece, but when I tried to trim it, it broke the foot like hard toffee that dropped on the floor! Link to comment Share on other sites More sharing options...
glazenerd Posted April 20, 2017 Report Share Posted April 20, 2017 poorly formulated cone 6 porcelain the root cause.. Link to comment Share on other sites More sharing options...
Kaolinwasher Posted April 21, 2017 Report Share Posted April 21, 2017 Nothing wrong with Custer feldspar it has 72.47 silica 15.24% alumina and 10.87KN so you need less silica in the porcelain. and its cheep , I do use mahivar as well they must float out the siica because it has only 67% silica and 17.5 alumina and 14.5 KN but its expensive Link to comment Share on other sites More sharing options...
porcelainbyAntoinette Posted April 22, 2017 Author Report Share Posted April 22, 2017 Hmm, worth looking into the Custer too. Some years back it was said that the g 200 was more pure. I just compared the two and it seems that the Custer is even less complicated. Someone said it changed,; I wonder if I still have the old one.........bought mine about 10+ years ago. Thanks Kaolinwasher.......I will check and definitely consider testing that in a recipe or 2 Link to comment Share on other sites More sharing options...
anchorman Posted May 11, 2017 Report Share Posted May 11, 2017 I have heard that it changed from a lot of folks, but who has actually had it tested? Pacer claims that it is very consistent on their website:http://www.pacerminerals.com/wp-content/uploads/2014/02/Feldspar_Tech_Data_Clarification.pdfhttp://www.pacerminerals.com/wp-content/uploads/2016/10/FELDSPAR-200-325-Tech-Data.pdfalso see digitalfire materials database/plainsman clays: https://digitalfire.com/4sight/material/custer_feldspar_253.html Hmm, worth looking into the Custer too. Some years back it was said that the g 200 was more pure. I just compared the two and it seems that the Custer is even less complicated. Someone said it changed,; I wonder if I still have the old one.........bought mine about 10+ years ago. Thanks Kaolinwasher.......I will check and definitely consider testing that in a recipe or 2 Link to comment Share on other sites More sharing options...
anchorman Posted May 11, 2017 Report Share Posted May 11, 2017 http://community.ceramicartsdaily.org/topic/16013-custer-has-changed-chemical-analysis-is-in-for-march-2017/?hl=custerThanks Min for sharing the above link with me. test, test test! both the analysis, and how it actually behaves in one's working process. Link to comment Share on other sites More sharing options...
porcelainbyAntoinette Posted May 11, 2017 Author Report Share Posted May 11, 2017 Thanks guys. Just received a bag of each "current" custer and mahavir. Will start testing next week. I am interested in a very white translucent workable porcelain clay body, with as little bentones in it as possible. It seems like I ran into a gold pot of gurus! Will keep you posted. Link to comment Share on other sites More sharing options...
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