This set of chisels was the first good-quality set of tools I bought in the early 90s. At the time, they were an upgrade to my hardware-store and hand-me-down chisels that I had been using. Eventually I bought better chisels, and these ones were relegated to the second tier. As a result, they took some abuse and neglect over the years. I finally decided the set needed to be restored to return them to daily use.
The largest chisel was in the worst shape, so I set it aside for a later restoration project and went about dealing with the remainder of the chisels. Since all of the chisels had at least one issue, the best way to deal with them was to treat them all to the same level of detail. For efficiency, it was easiest to perform the same step on the entire set to ensure they all came up to the same level. Sharpening, in general, includes three key steps to achieve a sharp edge – lapping the back, grinding the primary bevel and honing the edge. Restoring an old set of chisels requires all three steps for each one of them.
Lapping the backs of the blades started with a fine stone to see just how flat the back was to start with. Since these were mid-level chisels that had never been properly lapped, all required major treatment. This meant going to a coarse stone, such as a 320-grit diamond stone or a 220-grit water stone, to start. It isn’t necessary to flatten the entire back of the blade, but I wanted it to be mostly flat. Once the backs started to look almost flat, I switched to a finer stone, such as a 600-grit diamond or 1,000-grit water or ceramic stone. Switching to a finer grit sooner starts removing the scratches from the previous grit while doing a final flattening, reducing the time needed. All the blades in the set were lapped on a 1,000-grit stone for now, as grinding would likely introduce a large burr that would need to be lapped off later.
On a coarse 320-grit diamond stone, the back gets its first phase of lapping to get it close to flat.
Chisels that require heavy stock removal for either lapping or grinding are often better done on a diamond stone that doesn’t wear down during use. Ceramic or water stones can be used; however, they may require flattening to ensure the blades do not develop rounded surfaces when being worked.
The lapping continues until all the marks are gone and then moves to a 1,000 stone to clean up the scratches.
With all the chisels lapped to 1,000 grit on the ceramic stone, it was time for some grinding. These blades had been abused over the years, so a couple required the removal of some nicks. I did this on the bench grinder, removing just enough material from the end while ensuring it stayed square. All of the chisels, except for the ¼” and 1/8” ones, were ground to 25°, with the smaller ones ground to 30° as is standard practice for bench chisels. Most of these chisels needed major work on the bevel, so I started with some 80-grit sandpaper stuck to my granite block with a very light spray of adhesive. The granite block provides a flat surface and the sandpaper is easily replaced when spent, making a very cost-effective grinding medium. This entire set used two sheets. It helps to vacuum off the filings as they accumulate to avoid clogging up the paper.
All the backs have been lapped flat to 1,000 grit. They will receive final lapping after the primary bevels are ground.
The rough grinding is complete when the entire bevel has been ground and you can feel the beginning of a burr on the back edge of the bevel. Because the 80 grit leaves pretty good scratches on the bevel, I ran all of them over 120-grit paper on the granite to finish the grinding and to establish a burr on the back edge of each blade. This also helps save time and wear on the stones later. The rough grinding of this entire set took about 30 minutes, including the 120 grit clean-up step, making this technique a very efficient way for regular grinding of edge-tool bevels. The less-damaged chisels could have been reground on a 120-grit paper only in order to save a step.
The 80-grit sandpaper mounted to a granite block is an effective way to remove the material necessary to grind these blades’ primary bevel to the required angles.
With all the primary bevels ground to 1,000 grit, the chisels are ready for their final lapping and honing.
I next switched to the stones for a proper honing. But before honing the bevel, I finished the lapping. Starting on a 1000-grit stone, I lapped the back to remove the burr from the rough grinding and continued lapping on the finer stones to finish the back. Lapping is a key step in the preparation of the blade, as the polished back provides one of the two surfaces necessary for a sharp edge. For this reason, the back should be lapped to the finest stone you plan on using for the bevel. These chisels weren’t particularly hard, so I took them to 8,000 grit on the water stones. Higher quality blades or harder steels benefit from 10,000 or even 13,000 grit to get the finest edge.
With the primary bevels ground, all the backs are lapped to remove the grinding burr and polished to 8,000 in preparation for the edge honing.
With the backs all lapped to 8,000 grit, it was time to do the honing on the primary bevels starting with the 1,000-grit stone to polish the primary bevel through the remaining grits. If you desire a secondary or micro-bevel, the primary bevel does not require honing on extra fine grits and 1,000 grit is plenty for the primary bevel. All of these chisels received a micro-bevel, so I stopped polishing the primary bevel at 3,000 grit on the stone, which is a point of personal choice. I like a shinier primary bevel on my chisels. I switched to the micro-bevel setting in the honing guide and made a few passes over the 8,000-grit stone until I felt a small burr on the back. It was then time to remove it from the guide. I quickly lapped the back on the same 8,000-grit stone to remove the burr and these blades were like new and ready to use.
With the honing guide set for the micro-bevel, all the edges get a few passes over the 8,000-grit stone to raise a small burr. The burr is lapped off on the same stone and a set of chisels is better than new.
Text and photos by Richard Wile
Richard Wile is a lifelong woodworker and author from Nova Scotia. He continues to experiment and explore on his lifelong sharpening journey seeking the perfect edge.
