You Need Sharp Chisels and Planes
Sharpening chisels and planes is an important part of woodworking because a dull blade will lead to frustrating experience every time you use it. A sharp one that will take off an easy curl of hardwood is really a joy to work with.
Sharpening blades is an essential skill if you’re working with chisels and planes, and truthfully it’s not difficult to master. To start, you’ll need the following:
- A honing guide to hold the blade at the correct angle
- One or more sharpening stones (I use a medium and fine diamond stone)
- Some honing oil or mineral spirits, or water if you’re using a wet stone
- Something to sharpen
Steps for Sharpening Chisels and Planes
The key to getting a great edge on a plane or chisel blade is getting the correct angles when sharpening. The blade will have a “micro-bevel,” which means that the main edge of the blade is sharpened at one angle, then the very tip is at a different angle. This creates the micro-bevel. With some minor differences of opinion, the two key angles are 30 degrees and 25 degrees, respectively. Some specialized chisels such as pairing chisels may need different angles.
Flatten the Back of the Chisel
The first step to sharpening is flattening the back of the chisel. For this you won’t use the honing guide. The goal is to ensure that the back of the blade is completely flat at the end of the blade closest to the cutting edge. This is something that you typically will only need to do once. While holding the chisel flat against the coarsest stone you have, move the chisel back and forth. When you flip the chisel over you’ll be able to see how out of flat your chisel is. If you’re removing material unevenly, meaning your back is not flat, you may want to step up to a more coarse grit if it seems like there’s a lot of material to remove. You could also step up to using sandpaper glued down to a sheet of glass if you need something more coarse than what’s available in stones.
Step up through different grits to make the back of the chisel clean and flat.
Move to the Cutting Edge
Once the back is cleaned up, you can begin applying the bevel to the cutting edge. See your honing guide for instructions on measurement of the exposed blade from the end of the guide. In my case, for a chisel it should extend 40mm past the end of the honing guide to achieve a 25-degree bevel. Measure this out with a carpenters’ square and ensure that the chisel is mounted squarely in the honing guide.
Once everything is measured and setup, apply some honing oil to a medium stone and begin moving the blade and honing guide in a back-and-forth motion across the stone. Try to use a circular back-and-forth motion to ensure you wear the stone evenly. In this case I’ve chosen diamond stones because they hold their flatness better than wet stones.
After applying the 25-degree bevel on the coarse stone, it’s time to step up to the fine stone to give the bevel a finish. Typically less time is required on the finer stone.
Now repeat the steps, adjusting the honing guide to reflect the measurement for a 30-degree bevel. In my case this is a 30mm measurement from the end of the honing guide. Once the honing guide has been adjusted and you’ve re-checked square, it’s time to apply the micro bevel using a fine stone and honing oil. After the micro bevel has been applied, check your chisel to ensure that the micro bevel is visible and even – then check for sharpness.
Depending on your stones and desired level of sharpness, you may need to spend additional time on the micro bevel to get it to the level you desire. You’ll notice that after a single sharpening any re-sharpening will require much less effort.
While this may seem tedious at first, once you get in the habit of sharpening your tools you’ll realize that there’s no replacement for a sharp chisel (or plane) and the sharpening process will become quite natural. While there are many power sharpening options available, I still prefer to sharpen by hand.