Jump to content


  • Content Count

  • Joined

  • Last visited

  1. anchorman wow I didn't know that. Thank you for info. I'll try to avoid washing it off in a sink and utilize in some jar until figure out what to do with it.
  2. RonSa I'll check if it's possible to buy any of that, thank you. The main problem is companies sell these products in tons and roughly milled for major manufactors of ceramic tiles and such. But what the hell, I'll directly ask them. Thank you for pushing me to solving this. For now I buy from sellers that supply ceramic artists and it's not common here to make glazes instead of buying commercial ones. So I can't even ask for advice from locals. -__- glazenerd that clay has a firing range up to 6 cone, the higher it gets the more fragile. Also my kiln is not suitable for going that hot. I made that kiln specially for 1200-1230 range. I didn't have money to buy branded kiln, but I wanted to start so badly that was agree to anything, haha I hope to long for a few years until I make a better kiln for a higher temperature. I've found fine nepheline syenite (norwegian). For the moment I bought materials it was not available, but it is now. I'll buy next month. Min thank you for understanding my situation. I'll get another materials in next month. I'll post my progress and recipes here. Thank you all guys I realized my problem.
  3. Guys, thank you for trying to help, but I don't have any materials like gerstlay borate or spodumene or lithium or any other fancy stuff. I have very little of choice and I need to work with what I have. Min The reason I use borax is this is my source of Na besides Feldspar. I didn't yet find any other source of borax, but i'll search for it. Thanks! High Bridge Pottery thank you! The feldspar that I have now is very roughly milled. I was unlucky to buy it in large amount. The layer I get with it is quite thick and grainy and the glaze itself settles very fast and uneven. Here we're talking about thin layers, right? I've just found another seller with finer feldspar and neph. sienyte and I'll check those in some time. For now I need to stop working on clear glaze, maybe?
  4. oldlady thank you, I have barium and I'm totally okay using it in glossy well-melted glazes. for whatever reasons found in the internet recipes of barium matte didn't work out (overburn and I'm too lazy now to correct the recipes) and I'd like to use barium since I have it. Bryan Johnson I don't have a frit, they are quite expensive. I wrote list of materials I have in the first post and wollastonite didn't help. I believe my kaoline is already calcined, but I'd like to try. can you give me more info about it please? I haven't calcined anything before. Also, I'll try to decrease kaoline, thank you! BTW here's the recipe I use now and it looks promising to work on. Borax 31.91 Wollastonite 31.91 Calcined Kaolin 21.28 Silica 14.89 I reduced Sio2 as High Bridge Pottery adviced and it layes thin and has less bubbles than the others.
  5. High Bridge Pottery not this time, but I've checked previous tests and saw reducing silica gives unpleasant surface. The more silica, the better!
  6. glazenerd I've done tests and unfortunately it didn't help. I bisque fired to 1020 and then second fired slowly. My kiln does not heat up fast, it's a handmade thing, so it took around 3 hours to reach 1220 from 1100. I hold 20 min at top temp and let it cool as it goes itself. Probably I need to hold an hour maybe? Bubbles are still there, the same size, the same places. Thanks to bisque firing to higher temperature than usual glaze layed thinner, but I can still see bubbles in there and it's pretty obvious in spots I put colorant on.
  7. glazenerd your point is - it's definately the body and definately not the glaze? I would love that outcome, because I like my raw materials and changing contents would be troublesome. I'll try firing bisque at 1020C right away and check glazes No, there's no greens in glazes, it's a little yellow in some of them, if the layer is thick some clear are more yellow than another, but in daylight I can't tell without specific close up watching. I didn't put any colorants, maybe iron in some materials?
  8. Diesel Clay thanks, that's something I can work on too! I'll try different applications. glazenerd I never told it's a porcelain! I wrote semi-porcelain, a term probably not used anywhere else and I don't know to explain it in english. It's pretty cheap and easy to handle so I chose it for my ceramic start. I find greyish color beautiful and I don't want to use white porcelain so far. If you are curious about it: SiO2 67,0 Al2O3 21,8 Fe2O3 0,47 TiO2 0,5 CaO 0,45 MgO 0,3 K2O 1,7 Na2O 0,9 I'd like to have stoneware body in future but all I do now is dozens of glaze samples and fit recipes to temp around cone 6 so it doesn't matter to me. And what do you mean that it's not functional if the piece is covered in glaze? I gave a reply up there that bubbles do not appear with commercial glaze and I think the body is not the problem.
  9. Here are some recipes: FFF feldspar - 34 Silica - 18 wollast - 17 borax - 17 Kaolin - 10 dolomite - 5 FFF feldspar - 51 Silica - 28 whiting - 18 ZnO - 3 Kaolin - 11 Silica - 30 whiting- 10 borax - 15 Kaolin - 15 dolomite - 8 Talc - 3 These recipes may seem weird. I mix whatever I have and see what's going on. Reducing silica is a brand new idea for me. I thought the more the better! Without silica it's not glossy and tends to matte. I'll think what I can do, thank you! I've tried to reduce the surface tension with borax but it gives white clouds. It's a pretty effect actually, lovely white streaks when runny But not what I want in this case.
  10. Thank you all for answering! I use semi-porcelain, the color is greyish white, which I guess is similar to stoneware. Announced that it has around 6% porosity. Firing range from 1180C to 1220C. I fire to 1220 it's about 6 cone, but I don't really use cones. The reason why I think its kaolin because I 've read digitalfire article displaying small bubbles from kaolin. Of course they may be from anything else, but I'm pretty sure it's not the clay. I've had samples of commercial glaze and used it in the same conditions on the same clay and it came out absolutely perfect glossy bubble-free transparent and thick in application. I attached 2 pics, hope the quality is enough. Bubbles tend to move up to surface and I have needle size holes. I understand there's a moment where I need to hold temp so they move out, but I couldn't guess when exactly. -__-
  11. Hi guys. I've started my aquaitance with ceramics and glazes half a year ago. I still have a very basic understanding of chemistry and I have several problems I'd like to ask about. First is clear transparent glaze. I made around 10 of them taking different recipes, but all of them contain bubbles. I've tried bisque firing in various temps, from 600 to 950C and second firing slow cooling, dropping and slow cooling, but bubbles are there and their quantity is similar in all conditions. I know commercial glazes don't have such problems. Please help me to figure out what is going on. My thought is that my raw materials are the problem. I have very few materials for glazes, those are: feldspar, whiting, borax, dolomite, talc, silica and kaolin. Substituting whiting with wollastonite didn't help. The runnier the glaze the less bubbles it has, but running is provided with whiting and borax and I have white clouds coming along with bubbles. Less flux - no clouds, but still bubbles. I imagine it is kaolin that gives a lot of small bubbles. Any chances to fix that? I have stains and wish to use them in underglaze painting, so I need to make a decent covering glaze. For underglazes I bought a few frits, I don't know their formula, seller keeps it in secret, only mentioning temp range. I have 1 lead flux frit melting on 710C and other leadless on 1100C. I need to fire on 1220C, so I guess some kaolin may help to lift temp of frits melting so the stains won't burn out, but more bubbles again? If you have info how to win the fight with bubbles please share. Sorry if made any mistakes.
  • Create New...

Important Information

By using this site, you agree to our Terms of Use.