15 Things All DIYers Should Know About Bench Grinders
A bench grinder is probably not a tool you’ll use every day. However, if it’s available and set up correctly, you’ll be surprised how often it comes in handy for everything from sharpening tools to rounding over thread ends on a cutoff bolt. We’ve assembled these tips to help you get the most out of your grinder.
Keep a Container of Water Handy
Check out how to sharpen a lawn mower blade.
Make Tool Sharpening Guides
Here’s a better way to hold tools securely while you’re grinding them—and take the guesswork out of creating the right bevel angle. It’s a short piece of 2×4 with an angled end and a 1-1/4-in. hole for a clamp. I made one for chisels and plane blades, and a few more with different angles for wood-turning tools. Large labels with the tool’s name tell you which blocks are for which tools. For a Delta grinder with a 6-in.-diameter wheel, a 5-1/2-in.-long piece of 2×4 aligns the tool to the wheel just right. For other bench grinders, you may need to adjust this length. Note: The angle you cut on the block is not the same as the tool’s bevel angle. But let’s skip the math. To determine the block angle, turn off the grinder and hold the tool’s bevel flush against the wheel. The angle of the tool shaft to the workbench is the angle to cut on the 2×4. Our thanks to Ray Caputo for this sharp accessory.
Consider a Low-Speed Grinder for Sharpening
Dress Wheels Frequently
To use a dressing tool like this, start the bench grinder and wait for it to reach full speed. Then press the diamond wheel dresser against the spinning wheel, holding it perpendicular to the face of the wheel. Be sure to wear a good-quality dust mask. The fine aluminum oxide dust is very bad for your lungs. Draw a pencil line on the wheel before you start to help you gauge when you’ve removed enough material from the wheel. Dress the wheel just until the pencil line disappears.
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Watch for the Sparks to Come Over the Top
See more on how to sharpen a chisel.
Make an Angle Gauge
1. MARK THE ANGLE ON CARDBOARD
Align the center mark on the protractor with the top edge of the cardboard. Then turn the protractor until the desired angle is also aligned with the top edge. Draw a line along the protractor to mark the angle. Don’t forget to label the angle. Cut along the line to create the gauge.
2. ADJUST THE TOOL REST
Set the cardboard on the tool rest and adjust the angle of the tool rest until the wheel contacts the center of the angled portion of the cardboard gauge.
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Upgrade the Tool Rest
There are several variations, some made for specific tasks like sharpening lathe turning tools. This Veritas model has two adjustments for positioning and aligning the tool rest, and levers for easy tightening. You can also buy an attachment that holds chisels or plane irons.
See more on how to get the best out of your tools.
Make Your Grinder Portable
The stand is built from two 12 x 16-in. pieces of 3/4-in. plywood separated by two 4 x 12-in. uprights. We used two 5/16-in. bolts with washers and nuts to attach the grinder, leaving enough space in front of the grinder to mount a stand-alone tool rest.
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Easy-to-Clamp Mobile Base
Shazam! Fasten your bench-top tools to your workbench in seconds. Bolt 3/4-in. plywood bases on the tools and then glue and screw a wood strip along the front edge to fit into a woodworking vise. Crank this strip into a vise to lock the tool into place. If you don’t have a vise, drill a couple of clearance holes along the face of the wood strip on the base and drive screws through the strip into the edge of your workbench. Then just unscrew to remove the tool.
Set Up a Polishing Station
To use the polishing wheel, hold the stick against the buffing wheel as it spins to transfer some polishing compound to the wheel. Then hold the object lightly against the wheel and let the compound polish the surface.
Click here on how to sharpen garden tools.
Sharpen Your Lawn Mower Blade
Grind the tapered cutting edges with a grinder only if you see nicks in the blade. Follow the factory angle of the cutting edge. The grinder will remove nicks in the blade much faster than you can file them. Get the step-by-step info for this project here.
- Wear safety glasses with side shields, goggles or a face shield when grinding.
- Turn the grinder on and stand aside until the wheels come to full speed. If there’s a problem, you won’t be in the path of flying debris.
- Inspect grinder wheels for cracks or damage. Before you install a new wheel, suspend it by a screwdriver through the center hole. Tap the wheel lightly with the plastic handle of another screwdriver. The wheel should ring. If you hear a dull thud instead, the wheel is probably cracked and should not be used.
- When you install a wheel, don’t overtighten the nut. Just snug it up. Overtightening could crack the wheel.
- Keep the shrouds and spark shields in place. And maintain a 1/8-in. or less gap between the tool rest and the grinding wheel.
Check out these other tool safety tips.
Not All Grinding Wheels are the Same
You can use two kinds of aluminum-oxide wheels to sharpen your chisels; one is blue-gray and the other white. We used the darker-color wheel, which is harder and will keep its shape longer. The drawback, however, is that it grinds hotter than the softer, white wheel. Too much heat will weaken the steel. The soft wheel will need more frequent shaping with a dressing tool, but you’ll be less likely to burn the edge of your chisel while grinding. For best results, use a 100-grit wheel to shape your chisel blades. Learn how to sharpen your chisels like a pro here.
Know When to Replace a Wheel
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. Check out 30 more handy hints for your home workshop.