How to Use a Bench Grinder to Sharpen Tools: Complete Guide
Cleaning up old tools is not a problem. That is why you bought a bench grinder in the first place. You want to extend the life of your old tools and make them like new again. Bench grinders can easily handle just about any tool sharpening job you have
How to use a bench grinder to sharpen tools: One of the key steps you need to take is to keep safety first. You should wear eye goggles to protect your eyes and tight-fitting safety gloves to protect your hands. Also, you should use two hands when sharpening any tool to make sure you do not apply too much or too little pressure.
This is not the only way to sharpen tools. For more tool sharpening options simply continue to read. Our article is filled with the right information just to help you sharpen your tools on a bench grinder.
Using a Bench Grinder to Sharpen Tools 101
Using a Bench Grinder to Sharpen Tools
When you have a very dull or heavily damaged tools, skip the file and other hand tool sharpening options and head straight for your bench grinder. The bench grinder should handle any tool sharpening tasks with ease and save you a lot of time.
Here are some tips to help you sharpen your old tools on a bench grinder:
- Match the wheel to the metal being sharpened - it is the right tool for the job rule that always applies. For old tools, you may want to go with a 60 grit aluminum oxide wheel and medium hardness.
- Put the tools in your oven - not too hot just set your oven to 350 degrees and let the tools sit inside for 2 hours. This treatment will help prevent cracking when being sharpened.
- Mushroom ends are first - this will help you get the feel for sharpening. Use the edge of the grinding wheel to make short work of the mushroom look, then start on the tip.
- A little at a time - don’t try to get rid of all the metal at once. Take your time and do several passes. You need to be careful of any red hot pieces of metal that will come off as you grind away.
- Sharpen the tip - go slow, try to get a good edge and do not use a lot of pressure. Make sure you keep dipping it in cool water, oil or some other cool lubricant. Overheating the tool only works against you.
- Finally, use a wire brush - this will remove any rust that is on your old tools.
Bench Grinder for Sharpening Turning Tools
One tip that may help you when you go to sharpening your turning tools is that using a grinder is almost the same as using a lathe. The techniques are almost exactly alike. After that, you will find that sharpening your turning tools involve a lot of accessories and can get quite detailed.
Tools needed:
- 6 or 8” slow speed bench grinder.
- V tool rests.
- 80 grit grinding wheels.
- Diamond wheel dresser.
- Protractor.
- Permanent marker.
- It should be noted that different turning tools require slightly different techniques. This is due to the purpose of each tool. The following instructions are for the diamond parting tool.
- Use the protractor to help you set the tool rest’s angle to match the bevel to the wheel.
- Put your parting tool on the rest and line it up with the wheel.
- Mark straight lines with the permanent marker. This helps you keep the tool straight as you grind.
- Press the tool straight into the wheel.
- Continue till you get the angle of your edge just right.
The scraper:
- Adjust the tool rest to match the angle of the wheel.
- Use the permanent marker to color the edge of the scraper.
- Touch the scraper to the wheel. Adjust the tool rest till you get the wheel to the middle of the bevel.
- Keeping the scraper flat, gently push it into the wheel. Follow the shape of the edge.
- When the sparks begin to fly and land on top of the scraper and you can feel an edge, you are done.
The Skew Chisel:
- You want to have a flat bevel on both sides of the tool.
- Let the bottom of the tool hit the wheel first, then let the top side touch.
- Do this for both sides of the chisel.
- You want to end up with a 35 to 40-degree bevel on both sides.
- Pressure is not the key so be gentle as you move the chisel towards the grinding wheel.
- The Spindle Gouge.
- It takes practice but you want to roll the gouge up to the grinding wheel while at the same time sliding the wheel up along the grinding wheel.
- For best results, do not use the tool rest to help you steady the turning tool.
- You want to achieve a 25 to 30-degree bevel with a swept-back edge.
The Spindle roughing gouge:
- You are looking for a beveled edge between 40 to 55 degrees.
- To do this you set the rest so that the tool’s bevel rides against the grinding wheel.
- When the gouge just touches the wheel, use one hand to hold the tool and the other hand to spin it slowly.
- Once you have reached the other side, reverse your direction and do it again.
- Keep the end square to the wheel throughout this process.
- When sparks fly, you are done.
The Bowl Gouge:
- The goal here is to get a 75 to 80-degree bevel.
- You may need to use a jig to help you and once you have the tool inside the jig. make sure the end of the tool has a 2” inch overhang from the jig.
- Make adjustments to the legs of the jig according to the manufacturer’s recommendations.
- Place the legs in the V rest and turn the grinder on.
- Swing the jig into place next to the grinding wheel and gently apply the pressure.
- Sharpening turning tools is going to take a little practice to get it right. You are going to need patience and a steady hand to make the tools sharp again. The key is to make sure you get your angles correct and keep making adjustments to your tool rest.
- If you need to double-check to see if your tools are sharp enough, just run them across your thumbnail. If you take some of the nails off your tools are ready for action.
How to Sharpen Garden Tools With a Bench Grinder
There are smaller gardening tools that you need to keep sharp if you want your garden looking its best. The smaller tools are easy to handle and a bench grinder is a perfect tool for the job.
It certainly beats using a file and a vise. Here are 4 tips to help you sharpen your smaller garden tools:
- Don’t place the smaller tools in a vise - a vise may be good when you are hand sharpening any tool but not when you are using a bench grinder. A vise holds tools in place and does not allow for the natural sharpening motion needed when using a bench grinder.
- Do not place the blade flat against the grinding wheel - doing this will make the tool’s edge look nice and shiny but it will do nothing to sharpen it. You want to use a 45-degree angle to get the proper edge on your smaller gardening tools.
- Use a natural movement - Do not fight the grinding wheel but follow its lead as it starts to naturally pull a curved tool. Also, keep the tool moving. Holding it in place can ruin the tool and you will have more work cut out for you. Stay in control of the blade and your movements.
- Let the bench grinder do the work - while you still make movements and stay in control, it is the bench grinder doing the sharpening. You just direct where and how much the wheel does its job.
How to Large Sharpen Garden Tools With a Bench Grinder
You can sharpen larger garden tools on a bench grinder. Hand sharpening is always an option but if you do not have the time or the patience, a bench grinder does the trick as well.
1. Garden shears
- Unscrew the center nut and bolt and separate the two halves.
- Take one half and start up your bench grinder.
- Do not try to sharpen the inside flat edge. This will weaken the blade.
- Sharpen the outside bevel edge like you would any garden tool.
2. Lawnmower blades
- Unplug the mower or remove its spark plug first.
- Then turn the mower over and remove the blades. Make a note of which side is up. This is important as you do not want to re-install the blades the wrong way. Use a permanent marker to mark the up side.
- Turn your bench grinder on and once it gets up to speed, use a 45-degree angle to sharpen the blade.
- Keep the blade moving until done and then reassemble your lawnmower.
- Only one side of the mower blade needs to be sharpened.
More about lawnmower blades on our How to Use a Bench Grinder to Sharpen Lawn Mower Blades guide.
3. Curved garden shovel
- Clean the edge so you can see what you are doing.
- Start the bench grinder and wait until it gets to full speed.
- Move the edge of the shovel back and forth over the grinder until you have sharpened its edge.
- The shovel does not have to be too sharp.
How to Sharpen an Axe With a Grinder
The axe or hatchet will be sharpened in the same manner. It is not too difficult to do, the only trick you may have is how to hold the handle as you grind. The technique to sharpening an axe or a hatchet is similar to the one used to sharpen a lawnmower blade.
- Start the grinder and wait till the wheels are spinning at top speed.
- Gently press the axe or hatchet head against the grinding wheel. Remember, too much pressure can damage the wheel. Too little pressure will not get the axe or hatchet sharp.
- Slowly keep the blade moving. Do not stay in one place for too long.
- Use a 45-degree angle to get the right edge for your axe or hatchet.
- Do this for both sides of the axe hatchet head until you get the edge you need.
Some Safety Tips and Tricks to Use
When sharpening tools on a bench grinder, there are always safety tips and tricks you can do to make sure you do not hurt yourself, those nearby or your equipment. Here are a few of those safety tricks:
- Watch the sparks - when the sparks go down, that is when the tool is dull and you are starting your sharpening process. When the sparks go over your tool, then your tool is sharper than it was before and you are done.
- Get enough space - you can’t sharpen a tool properly, no matter its length if you do not have the right amount of space. You need to move freely. If you are bumped, you can damage the tool and you will have to start all over again.
- Get rid of the debris and flammable particles - to keep yourself, your workplace and friends safe, make sure you clean your grinding area. Sparks can start fires and damage the area around you.
- Earplugs are good - bench grinders can be noisy so it is a good move to insert some earplugs into your ears and cut the noise down. We have talked about protecting your hands, eyes, and face, now you should protect your ears as well.
Some Final Comments
Using a bench grinder to sharpen your tools is a smart move to make. It will help save you money and the bench grinder moves a lot quicker than hand sharpening. The main attitude to have is patience.
It will require several passes to get the right edge to your tools so take your time. There is no rush. If you get the tool sharpening task right, then you can get your other tasks done correctly and probably a lot faster.
Also, you would want to use a slow speed grinder. This gives you better control, and it is safer to use.
