Post #600368 by Babalu on Mon, Aug 1, 2011 7:45 PM

Hey Swizzle, It's really cool to see you sticking with it! Clay is addicting!!

One reason that cracks like that can occur is if you pool too much of the glaze on the bottom inside of the mug. The shallower thickness of the glaze on the inside side walls transitioning to the thicker glaze on the bottom inside can cause tension as you mention as the glaze is curing after the firing is complete, resulting in a sharp crack like the one shown. Just try holding that mug upside down a little longer when your pouring out the glaze. Make sure that when you set the mug back down on the table, glaze isn't running down the side walls and pooling. Hope that helps some...even if for some reason, the above mentioned, isn't the problem here with your mug, it's still a good thing to know. :)