[Michael C Henry]

I used the standard hole saws that I had or Home Depot sells. I allready have several different arbors.I also use a rotary file to open some holes and smooth and enlarge holes in fiberglass. Not too much speed = heat or they will fill up with resen. Some times you can use an old finish carpenters trick and not go all the way through and restart the hole saw from other side using the existijng pilot hole so not to tear out bryond the actual hole when going through.