Well, if you are considering to make some bowls or similar castings out of it, I suggest you cut it at suitable lengths and to make sure there is no moisture inside it, put it in the oven for 24 hours at the lowest temperature setting, 60° celsius is OK.
If you use Polyester resin, you need to consider the normal problems (cracking) on large pours so, you need to reduce the % of the catalyst at about 1/4 of the recommended amount, this will force the curing time to extend considerably and therefore, preventing the extreme heat that regular catalyst %'s would create in large pours, it may take a few days to cure but is safer that way...!
The brittleness often found with Polyester castings, particularly when the amount of catalyst recommended is exceeded (happens to those in a hurry...!) is prevented on these type of slow curing, after cured the resin is hard but is a lot softer to cut/work with, similar to Epoxy resins and Alumilite...!
Good luck...!
Cheers
George