no matter what you do it will crackle... it's excessively crackling because it's still wet, but you can't do anything about that either...

resin is mostly a tar substance(as with most anything else there are degrees of purity... the more pure, the more liquidy it will be...), therefore at heat it will liquify, and ofcourse with direct flame on it, it will boil/crackle/sizzle.. nothing to worry about...