Many homes have hollow-core interior doors. The thin plywood veneer of the door is supported by a wood frame and a corrugated cardboard web. Because the plywood is thin, it's easy to accidently knock a hole in it. This usually means you have to replace the door, cover up the hole or — repair it. That's right, rather than throw out a damaged hollow-core door, it's easy to "fix it" (or simply dress it up) by adding recessed panels.

To remove the veneer skins you need to use a jig saw to cut out the opening for the recessed panels. But a standard jig saw blade can cause excessive chipout.

So to solve this problem, I replace the standard blade with a reverse-cutting blade. Unlike a standard blade, the teeth on a reverse-cutting blade point down. So it produces less chipout.

Another problem may be the distance covered by the stroke of the blade. If it's too long, it will cut through the bottom skin of the door. Although you can't change the stroke of the jig saw, you can shorten the blade to keep it from cutting all the way through.

To do this, first set the base of the saw on the edge of the door, see the drawing at right. With the blade extended as far down as it will go, mark it just above the bottom skin. Next remove the blade and score it at this mark with a file. Then secure it in a vise and cut it to length with a hacksaw. Now you're ready to safely cut clean openings in a hollow-core door.