Crazing and crawling

Nothing really came out well from this kiln batch,except for the pieces with only a single glaze applied. The pieces that were slipped and/or slipped and carved, then glazed after the bisque stage all have problems. The main one is crawling--patches where the glaze didn't adhere and bits of the clay are exposed. I realized only after looking at the photos on my laptop that my golden brown byzantine bowl has crazed like mad. I'm not sure the full reason for either problem--I know in theory what causes crazing and crawling, but why it happened in these cases I don't know. I do suspect thermal shock on the crazed bowl, though. As I was carrying things to the car I heard the tell tale 'ping ping' of cracking glass (or in this case, glaze). The crawling is more worrisome, but I'm working on a slipped pitcher right now and will be particularly mindful when I glaze it to make sure there's no dirt or oil on either my hands or the pot! Oh, and I chipped the rim of my little yellow Byzantine cup. Very sad, all the way around. Back to the studio tomorrow, of course!