Not entirely sure what happened to this mug! I had adjusted this glaze - Magic White - with the addition of a small amount of silica, because it was inclined to crawl, and a bit of CMC gum, because it was very fragile in the dry state. Only this mug and one other exhibited this very weird curling and flaking, though I used the glaze on many pots in this load, which is scheduled to fire on Monday. The other possible contributing factor is that this bisque got a little hotter than usual - probably ^04 - 03, where I prefer not to bisque above 05, because the ware gets too vitrified to accept glaze well. I guess that could account for it: the body is not absorbing moisture, so the glaze is only drying from one direction.
That doesn't explain why it only happened on two pieces. Not that I'm complaining! Just a weird vagary of the ceramic process, I guess; or the action of one of those five demons I was telling you about.
No matter! I'll wash it and glaze it again - in something else, thankyouverymuch.
now it's a piece of sculpture
ReplyDeleteoh I recently decreased my bisque to 05 instead of 04 and it did help with the glaze adhering much better.
ReplyDeleteLinda - yes, that makes sense. Just too vitrified at 04 and above. I'll be interested (interested: that's one word for it!) to see how this glaze behaves on the pots it did adhere to! I'm worried of course but not so worried that I feel like washing them ALL off and ditching the bucket of glaze.
ReplyDeleteI've had issues with glaze peeling and flaking prior to firing, but not to the extreme that you're experiencing. I think mine was due to too much water in the glaze mixture which caused major shrinkage.
ReplyDeleteIt does look pretty cool though ;)