Bradleyfett
Active Hunter
Have you tried pre-drying it in a hot box for a day? You can make a hot box out of plywood, with a plain light bulb in the bottom as a heater.
I've tried several things, including something like you mentioned, but I still end up with a batch of plastic that works maybe 1 out of every 4 sheets. I just decided to stick with Kydex when I need something like ABS- its more expensive, but much more reliable.
Mark