That must be so annoying!
Keeping soft glass marbles in one piece without them going straight into a kiln is tricky. But you'd think that if you could make it work with a fiber blanket, you should be able to make it work with vermiculite.
One thing I can think of is that maybe the marbles touch each other in the crockpot? So one will have cooled down quite a bit, and then gets 'hit' by a really hot marble coming in.
Another thing I can think of is the tool you use to put the marble in the vermiculite. That is a step that you have probably changed from how you would put them into the blanket. Maybe your tool is too cold?
For my pieces that do not need to go straight in the kiln, I use Japanese annealing bubbles. They are not an actual alternative to annealing, but they are much nicer to work with than vermiculite in my opinion.
Good luck!
|