There is a tremendous amount of friction built up in the shot
during each run with any magnetic tumbler. I know you’ve felt
how HOT that water is after just a short 30 minute run. When you
switch between bowls, are you letting the first (hot) bowl cool
down and then starting fresh with cold water? That is best.
If you’ve been doing that and still getting cracks, please let
me know - you can email here or direct (@ElaineEC) or call
me at 1-800-544-2043, ext. 287.
Thanks. Meanwhile I will contact the vendor and see what they
have to say and let you know. (They are in Korea so the answer
will be a couple days at least.)
GESSWEIN CO INC USA
Tech Support: 1-800-544-2043