Chantay Posted June 8, 2015 Report Share Posted June 8, 2015 I have several pieces from my last firing, both red and white stone ware, cone 6. Also, two different glazes had the same problem, with spots where the glaze came out extremely thin, just a touch of color. Its like the glaze slid off the piece. Attached is an example on the white stone ware. Any ideas what happened? Link to comment Share on other sites More sharing options...
neilestrick Posted June 8, 2015 Report Share Posted June 8, 2015 That's crawling. Lots of possible reasons. There's been a fair amount of talk about it here lately. Do a search and you should be able to find lots of info. Link to comment Share on other sites More sharing options...
Joseph Fireborn Posted June 8, 2015 Report Share Posted June 8, 2015 When I fire my test tiles. If I put on too thick of application on the third dip, I always get crawling on that corner. It looks just like that. Link to comment Share on other sites More sharing options...
Chantay Posted June 8, 2015 Author Report Share Posted June 8, 2015 OK, crawling make since. I had just never seen spots this large. I had a lot of trouble with the last batch of glazes I mixed up. One was gelling and thick. But when I added water it just became runny and prolonged the drying. I am thinking it was over flocculated. Link to comment Share on other sites More sharing options...
neilestrick Posted June 9, 2015 Report Share Posted June 9, 2015 OK, crawling make since. I had just never seen spots this large. I had a lot of trouble with the last batch of glazes I mixed up. One was gelling and thick. But when I added water it just became runny and prolonged the drying. I am thinking it was over flocculated. That's very possible. And when the water content is too high the clay can become over saturated and lead to crawling. Link to comment Share on other sites More sharing options...
GiselleNo5 Posted June 9, 2015 Report Share Posted June 9, 2015 So far anything I've had that has crawled has been because the glaze was on too thick, but I know that's not the only possibility. My dad just had six pieces in his last kiln load that he dipped in the same glaze and every single one crawled beyond belief all around the rims because of too-thick glaze application. Looked very much like your photo. Before that I'd seen it mostly on the center of plates. Link to comment Share on other sites More sharing options...
Chantay Posted June 9, 2015 Author Report Share Posted June 9, 2015 Giselle, Im sure that was the problem. I had added water to these two glazes that crawled, but they were over flocculated, so the addition of the water didn't help. I will add some epson salt and dip test tiles before I use the glaze again. Maybe I used to much bentonite when mixing. Link to comment Share on other sites More sharing options...
RobS Posted June 9, 2015 Report Share Posted June 9, 2015 Epsom salt is a strong flocculant, adding that to an already overflocculated glaze will result in pudding. Try some Darvan 7 or sodium silicate. In the past, Calgon was also used as a deflocculant (it contained soduim polyphosphate) but I think they changed the formula and I don't know if the new stuff works as a defloc agent. Someone here probably has tried it and can verify. Good luck. Link to comment Share on other sites More sharing options...
GiselleNo5 Posted June 11, 2015 Report Share Posted June 11, 2015 Is it an option to let it settle and pour off some water, or would that take too long? (Please forgive me if that's a silly question. I've never used dipped glazes.) Link to comment Share on other sites More sharing options...
Callie Beller Diesel Posted October 5, 2015 Report Share Posted October 5, 2015 Is it an option to let it settle and pour off some water, or would that take too long? (Please forgive me if that's a silly question. I've never used dipped glazes.)It's not a dumb question. If you leave it overnight, it *ought* to settle out somewhat, especially if there's too much water. Skim as much as you can out and reserve. Mix your glaze back up and check your specific gravity with a clear plastic drinking cup that you calibrate to 100 mL on your scale. (100 g of water = 100mL) Add the reserved water back in as needed. When you get it to the right application consistency, record this number for future use. It seems like cone six must be rather prone to this kind of consistency problem. Link to comment Share on other sites More sharing options...
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