I have had several people ask me how I "cup out" my popper mouths, so yesterday I took a couple pics while I was working on some.
The bit I use is called a "round rasp bit" or a "ball rasp bit" it is approx. 3/4 inch in diameter I think (I will check that). You must take the plug carefully and using both hands place it up against the bit and apply a little pressure to get the bit started. Once it has a good bite into the plug, I roll the plug in a circular motion to deepen and widen the hole. Now since the bit is only 3/4 inch and I need to make a cup hole about twice that sixe I then work the bit slowly and carefully around the rim of the mouth to shape it out a bit. I stress slowly and carefully because if you should slip or the plug should slip, you will either A. Chew the hell out of the plug thus ruining it or B. Chew the heck out of your finger so please be careful and take your time.
