Bench grinder wheels need occasional TLC to do a good job of sharpening. Learn how to "dress" a wheel to keep it clean, which type to use for which metal, and how to test for cracks.
Rest the dresser on the tool rest and start the grinder. Then turn it off and press the tool against the grinding wheel as it slows. Repeat several times until the wheel feels rough to the touch (wait until it stops, please!).
This "star wheel" dresser removes built-up grains of metal that clog the wheel grit.
Slide the wheel over your finger and tap the wheel in four places with a screwdriver handle. All taps should sound the same. If they don't, scrap the wheel. It's cracked.
Lots of DIYers own a bench grinder. But not everyone knows which wheel to use for which metal or how to care for the wheels. So we consulted the experts and came up with these nuggets to keep you in the grind.
First, use aluminum oxide wheels for ferrous metals and silicon carbide for all the others (brass, copper, aluminum).
Next, dress the wheels regularly to remove clogged grains. Use either a “star wheel” dresser or a diamond dresser available through our affiliation with amazon.com. The diamond style (not shown) “retrues” the wheel a bit. But don’t expect either tool to “resquare” your wheel—that kind of rig costs a bundle.
Theoretically you can keep using your wheels until they wear down to the label. But you should replace them when they’re too small to use with the tool rest. Before you install a new wheel or reinstall a used one, always “ring-test” it to make sure there are no cracks (Photo 2). Tighten the wheel only enough to prevent it from slipping. Overtightening can crack the wheel.