[George Snyder]

Blackjack,
The hole saw will work. Just stack them . The new size on the mandrel first, followed by the old size. The inner one, old size will act as a big pilot bit and align the new one.

We use this method when one of the guys drills the wrong hole in a pipe for a mechanical tee.

Fibergless should be a piece of cake, but go slowly.

Bud