Post #411609 by MadDogMike on Sat, Oct 4, 2008 8:00 AM

The crack started in the greenware, no I don't have any pictures. It wasn't bone dry when it developed so I tried brushing slip into the crack by that didn't work. I even tried digging the crack out and backfilling it with thick slip like Mishima. I hear adding vinegar and/or baking soda to the slip helps?

I think I know of 2 reasons why it cracked;
1 - it's handbuilt and much thicker than the slipcast pieced I've made. I think I tried to dry it too fast, still trying to learn patience :)
2 - it isn't footed, just a big flat bottom. I covered it over with plastic to dry slowly but the bottom was just sitting on the formica tabletop. The part in contact with the table dried more slowly than the inside of the mug that was exposed to some air. Plus the bottom probably grabbed the table and couldn't move as it dried, stressing the clay. From now on I'll dry on several layers of newspaper.

Good thing I low fire glazed it or it probably would have been a disaster! Drying more slowly is gonna kill me! I want to fire NOW! I'm working on a decorated peep hole plug that will be somewhat thick, I guess I'll have to try the "turn the bag insideout everyday" technique. At least this is a mold, if I screw up it's easier to start again.

CRACKS SUCK!!! If I liked crack I would have been a plumber :lol:

EDIT: I don't have a pre-glaze pic but I guess I can post a post-glaze pic. It doesn't seem to leak, but since it's low fired and not vitrified, it isn't safe for food consumption as is.

There are those few who learn from observation. The rest of us need to piss on the electric fence and find out for ourselves.

[ Edited by: MadDogMike 2008-10-04 08:29 ]