Posted for "Neal Garvin" <ngarvin@comcast.net>:

Ed,

For drilling fiberglass, plexiglass, plastic etc, you should be using
low-helix or "slow-spiral" type drills. They have a different tip angle that
won't try to screw its way through the fiberglass.

Available through most industrial supply. I get mine from McMaster-Carr
Supply.

Another way to do it is by starting with a smaller size drill then use a
hand tapered reamer to bring the hole out to size.

-Neal Garvin