Lucy GReen Posted January 2, 2021 Report Share Posted January 2, 2021 Hi, I'm a ceramic degree student and I'm currently working with Egyptian paste which is a form of self-glazing clay body. My question is; I really want to make it foamy and cratourous like a volcanic glaze but I'm unsure what ingredients specifically cause this reaction to happen. Does anyone know? Many thanks!!! Link to comment Share on other sites More sharing options...
liambesaw Posted January 2, 2021 Report Share Posted January 2, 2021 Silicon carbide. The larger the particle size, the more violent the off gassing is. Link to comment Share on other sites More sharing options...
liambesaw Posted January 2, 2021 Report Share Posted January 2, 2021 And just to add, since I know just a slight bit about egyptian paste, it uses copper as a colorant which will not play nicely with SiC. The SiC will reduce it locally into red and/or black mottles. I also think it may not volcano at all since egyptian paste never forms a melt, it simply relies on a crust of salt to form on the surface which then has a very localized fluxing. But certainly try it out and report back. For starting amounts of SiC, look up some lava glazes on glazy.org and copy the amount for a recipe you like the look of. Link to comment Share on other sites More sharing options...
Sorcery Posted January 2, 2021 Report Share Posted January 2, 2021 Nice. I've been getting "good" gassing up at cone 6 with dirty yard clay. I reckon you'll quickly find something to add at Egyptian Paste Temps to gas you off. Try things that melt/boil/volatilize around peak temps. Sorce Link to comment Share on other sites More sharing options...
Lucy GReen Posted January 2, 2021 Author Report Share Posted January 2, 2021 3 hours ago, liambesaw said: And just to add, since I know just a slight bit about egyptian paste, it uses copper as a colorant which will not play nicely with SiC. The SiC will reduce it locally into red and/or black mottles. I also think it may not volcano at all since egyptian paste never forms a melt, it simply relies on a crust of salt to form on the surface which then has a very localized fluxing. But certainly try it out and report back. For starting amounts of SiC, look up some lava glazes on glazy.org and copy the amount for a recipe you like the look of. Thank you so much for your reply! I also use manganese and chromium to colour my Egyptian paste as well as copper. Would either of them be a better option as appose to the copper do you think? Link to comment Share on other sites More sharing options...
liambesaw Posted January 2, 2021 Report Share Posted January 2, 2021 2 hours ago, Lucy GReen said: Thank you so much for your reply! I also use manganese and chromium to colour my Egyptian paste as well as copper. Would either of them be a better option as appose to the copper do you think? Manganese will probably work just fine Link to comment Share on other sites More sharing options...
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