Recently we have been having trouble with our paraffin blocks cracking. 
Sometimes they crack through the tissue, other times it cracks around
the tissue.  The worst cases will split along the crack when floated on
the water bath, and then separate.

We are using the same paraffin, but our embedding unit was worked on
and we do not know if the temperature of the cold plate was adjusted.

Could the cold plate be to cold, or are we leaving the blocks on the
cold plate to long?

Thanks in advance for any help you can give.

Tammy