Search the Community
Showing results for tags 'glaze problems'.
Found 3 results
I am perplexed why I get this crawling in about 1 in 10 mugs. The mugs are poured in an old hand built mold, from large batches of slip. At leatherhard cleaned up and sanded when dry. I rinse them all well with a clean sponge after bisquing and allow to dry 24 hours before glazing. The glaze is a large batch I’ve been using for a year. I’ve never seen this on anything but these mugs.
Can anyone tell me why I am getting blistering at the bottom (only) of the piece when using this homemade glaze? Its called Westcountry Water and is: Silica 36 Potclays/BPS High Alkaline Frit 30.5 Devon China Clay 20 Gillespie Borate 12 Whiting 1.5 Total Base Recipe 100 Zircopax 4 Bentonite 3 Copper Carbonate 2 Total 109 Otherwise, a very satisfactory glaze.
Please help!! I have been using all commercial bisque and commercial underglazes (duncan and mayco) with duncan pure brilliance dipping glaze for several months now with mostly good success. This latest piece is troubling and I am not experienced enough to know what the problem is or how to fix it. Please see the attached photos. The black lettering is not "attached" to the body of the piece in a few areas and there seems to be tiny clear bubbles laying on the surface of only the black lettering. Also, the colored glaze is cracked in places, but only near the lettering... A few other side notes that may be helpful to know. #1--I attached a picture of the pyrometric cones used during this firing. The curved tip indicates that the kiln fired hotter than cone 06, correct? Is this what caused the problem? If so, how do I correct it? #2--The Pure Brilliance Dipping glaze is supposed to have a viscosity of 19-24. I was getting a 16-17. I'm pretty sure I accidentally introduced water to the glaze when wiping down the sides of the container with a sponge. I will try to siphon some of the water out, but could this lower viscosity level be the problem. #3--I had several other pieces firing at the same time and all of them turned out okay. Could the problem have been the thickness of the black underglaze applied? I am truly hoping one of you can help me, but I am also interested in other resources for troubleshooting, so I don't have to bother people. I would welcome recommendations of all kinds--books, websites, etc...