Ask five people how to sharpen hollow chisels and you'll get five different answers. Here's one way that works well for me. Buy a small cone-shaped grinding wheel and check that the tip matches the hollow chisel. To get a picture of the interior geometry, press the end of the chisel into modeling clay (or Play-Doh*).
To sharpen the chisel, reduce the speed of the drill press to near 500 rpm, and put the grinding wheel in the chuck. Holding the hollow chisel vertically, press the business end up against the stone, using only moderate pressure. Dip the chisel
To sharpen a hollow rhi*el, hold the end up against a cone-shaped stone until you feel a burr on thr outside* edges.
in water at the first sign of overheating. Continue sharpening until you feel a distinct burr on all four sides. (A lathe works equally well for this operation.)
You'll sec that a small area is untouched by the grinding wheel. Clean up these areas with a small triangular file. Lay the chisel on an oil stone or water stone-about 1.200-grii—and gently hone each of the four flat surfaces until the bun-has gone. This will work for any hollow chisel from \\ in. up to V* in.
You can also get a cutter designed specifically for sharpening hollow chisels (available from Record Tools, North America, 1915 Clements Rd., Pickering, Ontario, Canada UW 3VI, 800-267-8367). It looks like a metal countersink with an attached pilot. You put the hollow chisel in a vise, insert the cutter in the chuck of a brace, and rotate it, using only moderate pressure. Clean up the inside corners of the chisel and hone as described previously.
The bit inside the chisel must also be kept sharp. If dull, it will clog up and wear more rapidly. The only way to sharpen these bits is with a small triangular file. If a bit has been damaged when pulled up into the hollow chisel, replacing it is about your only option.— S. W.
for $ 1,2(K). a heavy-duty router mount-ing carriage that travels on an adjustable radial arm. This converts the router into a precise joint-cutting and shaping system.
Horizontal boring machines are ideal for cutting mortises. When equipped with a sliding tabic, clamps, and stops, these machines still produce the fastest, most accurate mortises, although ilie resulting mortises have rounded ends.
Horizontal boring machines are often incorporated into combination machines such as the Shopsmith, Robland, Kity, Felder, and Total Shop. For clean, accurate cutting, the choice of bit is crucial. A quality end-mill cutter would be my firsi choice.
If you have the floor space—and don't mind a bit of tinkering—there-are two other options worth considering. You could look around for a vintage drill press and dedicate it only to mortising. Ii might require a general tune-up as well as some modifications such as longer handles, for example.
The other possibility is to hunt up an industrial mortising machine. ITicse are massive, cast-iron affairs widely used in production shops years ago. Composite materials and new fastening methods are making them obsolete, so sometimes you can get one for a reasonable price. Industrial floor models have either a hand-operated or foot-
operated chisel. The work is clamped to a cast-iron sliding table equipped with adjustable stops.
Before making a final choice, don't forget to explore the second-hand market. Finns that handle used woodworking machinery arc listed in the yellow pages. A
Was this article helpful?
Is your home bursting at the seams with stuff? Is every closet crammed so full that any one of them is a death trap waiting to be opened? Has it been years since the last time you parked the car in the garage? Never fear, help is on the way. You need to get rid of some of that stuff. Dont you dare call it junk. Remember, one man or womans trash is another ones treasure!