Block blowout without a backer board

First, mark and drill a small pilot hole in the desired location. Don’t worry about backside blowout, here. It will vanish when you drill the larger hole.

Q:

I have to drill a large access hole in a cabinet. Unfortunately, my clamps won’t reach to secure a backer board. How do I prevent the plywood from blowing out?
—David Wise, Fresno, Calif.

A:

If you can’t clamp on a backer board, David, instead create two clean fronts by drilling from both directions using a starter hole to guide you, as shown above.