[Delw]

what type of bait is it? is it a bigger bait that holds lots of plastic.?
whats happening is that the plastic stays hot longer( cause its bigger) and so the salt being heavier sinks too the bottom. you can try to lower the heat temp of the plastic and that may suspend the salt more. if not throw a pc fan on the bottom side of the mold so it will cool the plastic faster.

a stand up mold( 2 piece) will disipate heat faster thats why unless the plastic is extreamly hot it wont settle as fast.