Rita Mattson Posted October 19, 2020 Report Share Posted October 19, 2020 I made this glaze using a recipe from the 33 Tried and True Glaze Recipes published by Ceramics daily.org, but have had problems with it flaking off of bisque ware. I tried adding an epsom salt solution to the second glaze pic, but it still flakes off. What can I add to this already made glaze to prevent this? Thank you, Rita Wright’s Water Blue GlazeCone 1-6 OxidationGlaze MaterialPercentage Lithium Carbonate 3% Strontium Carbonate 9 Frit 3110 59 Edgar Plastic Kaolin 12 Flint17 Total100% Add:Bentonite2% Copper Carbonate5% Link to comment Share on other sites More sharing options...
liambesaw Posted October 19, 2020 Report Share Posted October 19, 2020 I'd try taking a small amount and deflocculating it with sodium silicate and see how that works. It looks like it's shrinking too much and flaking off. Link to comment Share on other sites More sharing options...
Bill Kielb Posted October 19, 2020 Report Share Posted October 19, 2020 33 minutes ago, Rita Mattson said: Cone 1-6 OxidationGlaze MaterialPercentage Hmm, big range there. Seeing what I am seeing I would likely give up on it and make something easier to work with. Link to comment Share on other sites More sharing options...
Min Posted October 19, 2020 Report Share Posted October 19, 2020 @Rita Mattson, are you brushing this glaze on also? Like was mentioned by Liam in your other post about issues with a clear glaze, a dipping glaze doesn't work well by brushing if it is only mixed with water. It needs to be made with either a commercial brushing medium or you need to make your own CMC gum solution and use that as part of the water content of the glaze. I think your cracking issue could be from too thick a layer of glaze. To make your own CMC brushing medium sprinkle 35 grams of CMC powder into 1 litre (or quart) of very hot water. Mix it up a bit, it will clump but don't worry about that for now. Leave it sit overnight then blend it with an immersion (stick) blender. There is no one magic amount of this you will need but for a start try using 1/3 brushing medium and 2/3 water when you mix up your glaze. Since this glaze has a large amount of copper in it you won't need to add any to stop the CMC from rotting. For glaze recipes like your clear from the other thread add about 1/8 tsp of copper carbonate with the CMC, it acts as a preservative and the tiny amount won't effect the colour of the glaze. BTW this glaze will more than likely craze heavily on any pretty much any claybody. Link to comment Share on other sites More sharing options...
Rita Mattson Posted October 19, 2020 Author Report Share Posted October 19, 2020 thanks so much for the advice. I will try making my own CMC brushing medium. -Rita Link to comment Share on other sites More sharing options...
neilestrick Posted October 20, 2020 Report Share Posted October 20, 2020 @Rita Mattson Are you sieving your glaze when you mix it? I see a lot of chunks in it. Link to comment Share on other sites More sharing options...
Babs Posted October 20, 2020 Report Share Posted October 20, 2020 This is a problematic glaze for most people. Why it is included in tried and true is beyond me. Hates being applied thickly. It has been reworked on this forum and on Glazy Top end C 6 it blisters, Clean damp wiped smooth pots, thin glaze app. I added silica, some have added zirco. There are other clear turquoises with less problems for sure. No room for tissying with glaze. Leave any drips alone as where thicker app. It flakes. I move glazedlazed pots by putting my hand into them and opening hand to get leverage. Don't touch rims etc. Sprayinga little water on cracks can help if only one or two. Fussy Link to comment Share on other sites More sharing options...
Roberta12 Posted October 20, 2020 Report Share Posted October 20, 2020 15 hours ago, Min said: @Rita Mattson, are you brushing this glaze on also? Like was mentioned by Liam in your other post about issues with a clear glaze, a dipping glaze doesn't work well by brushing if it is only mixed with water. It needs to be made with either a commercial brushing medium or you need to make your own CMC gum solution and use that as part of the water content of the glaze. I think your cracking issue could be from too thick a layer of glaze. To make your own CMC brushing medium sprinkle 35 grams of CMC powder into 1 litre (or quart) of very hot water. Mix it up a bit, it will clump but don't worry about that for now. Leave it sit overnight then blend it with an immersion (stick) blender. There is no one magic amount of this you will need but for a start try using 1/3 brushing medium and 2/3 water when you mix up your glaze. Since this glaze has a large amount of copper in it you won't need to add any to stop the CMC from rotting. For glaze recipes like your clear from the other thread add about 1/8 tsp of copper carbonate with the CMC, it acts as a preservative and the tiny amount won't effect the colour of the glaze. BTW this glaze will more than likely craze heavily on any pretty much any claybody. I used this glaze in the past. It crazed badly on any clay I used it on. I do not remember having the extreme flaking as I was glazing, but I do remember it was a very problematic glaze after firing. What temp was your bisque fired to? Link to comment Share on other sites More sharing options...
Rita Mattson Posted October 22, 2020 Author Report Share Posted October 22, 2020 I fired my bisque to cone 06. Glad to hear that I'm not the only one having difficulty with this glaze. Thanks so much for your response. -Rita Link to comment Share on other sites More sharing options...
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