Using Your Belt Sander To Sharpen… A Knife ?
You’re probably pretty good at finishing smaller wood pieces or other components for bigger pieces using your belt sander, but did you know that these machines are built for more purposes than just smoothing wood?
With the same power and capacity, you can definitely use your own belt sander to sharpen metal tools; knives, to be precise. You may be surprised to know that professional knife craftsmen and restorers have belt sanders dedicated to the task of sharpening the edges of a blade.
You Will Need
- A Stationary Belt Sander
- Sanding belts of various grits (150, 240, and 400 grit; also, 9 and 20 micron)
- Leather strap (optional)
- Compound for honing (optional)
- 1. For an initial job, choose a lower grit (150) for knives that do not cut anymore. If the knife can cut, but has a hard time doing it, then you can step up to 240-grit sandpaper. Load whatever belt you choose onto the sander.
- 2. Switch the sander on, and take the knife to be sharpened.
- 3. Make sure the blade is pointing to the same direction that the paper is moving to and approach the sander with the knife positioned at an angle of around 20 degrees.
- 4. Proceed to move the blade across the moving belt, always making sure that the edge is always perpendicular to the belt, for an even sharpening. Now, though you are sharpening metal, a lot of it can be quickly eliminated, especially by rougher belts. Make sure that you avoid running the blade through the belt for more than 5 seconds. If you’re feeling that the blade is getting hot, then you are sharpening the edge too much.
- 5. Repeat step 4 on the other side of the knife.
- 6. Switch to finer belts for a smoother finish. For most cases, you only need to progress from 240 grit to 9 microns, but if you’re sharpening razors and scalpels, you may need to take an extra step of using leather and an appropriate honing compound.
- 7. Test the blade; sharpened knives should cut through the paper from edge to edge with ease. Razors should be able to cut through hair as easily. The blade should look as it was when first purchased.
- You should be able to purchase honing, or stopping compound wherever belts are sold.
- When you progress to finer grits, you may notice the formation of a burr or an edge of excess metal that tends to drag over material as you attempt to cut. Take precautions to sharpen, while avoiding a burr that would hinder any slicing jobs you will be doing.
- You can also use a belt sander to clear older knives that have a bit of rust on them. This is achieved by moving the entire blade of the knife across the belt.
- Always wear the proper protective gear when using a sander. Goggles or safety glasses are a must.
- Make sure that your work area is clean and free of dust, especially since sharpening metal produces sparks that could ignite any residue from previous wood sanding jobs.
- You can only sharpen a knife with a stationary belt sander; both hands need to be engaged when running the blade across the belt. Handheld belt sanders have other entirely different purposes.