[Next time, put that pipe in the freezer for a few hours. The wood will shrink, thats all you need to do most of the time.
Sorry about the pipe Seanz...]
That was my hint also. The plastic should shrink more than the wood. Heating the bit will cause it to expand and fit tighter so do not heat it. You could heat the wood and cool the bit. Then the shank would expand and the bit would shrink which is what you want to happen. 8O