I use my pneumatic impact hammer for chipping back stucco and concrete, but I’ve been reluctant to use it on wood for lack of a proper cutting tip. Then I found a tip called a mufflercutting attachment, and I ground a chisel edge on it, as shown in the drawing. The chisel goes through dry Douglas-fir knots and end grain as if they were cheddar cheese. But because I can go full blast or just squeeze off one or two strokes, cutting action is safe and controlled (obviously, you should wear your goggles when using this rig).
The muffler-cutter steel is soft, so it won’t cut nails. But it sharpens easily with a file, and for this type of work, you don’t need to worry about microbevels.
One day, our crew’s door doctor came upon the ultimate door hassle: The subfloor at the back of a pocket door rose up too much to let the door open completely. So we welded up a 3-ft. version with an old chisel on one end, a length of 1/2-in. pipe in the middle and an adapter from another cutting tool on the other end. It took longer to clear away the chips than it did to cut down the floor.
Now I keep my impact hammer and the chisel attachments around for a variety of jobs — for when the header is an inch too low or when I need to carve a channel for a steel strap or when our plumber remembers the waste and overflow after the tub’s already in.
Gregg Roos, San Francisco, CA