Tales from the saw shop: jointing saws, changing tooth profiles, and snaggletooth..


Vern Burke, SwiftWater Edge Tool Works

Today was a day of challenges in the saw shop.

The first thing brought to me today by a local cabinet maker was a small vintage Disston dovetail backsaw. Other than being phenomenally dirty (hey, look, there’s a nice Disston etch under all that crud!) and wrong handle screws (nope, a vintage Disston backsaw handle should not have a medallion, much less an HK Porter era “Disson USA” steel medallion.), the little backsaw’s biggest problem was a severe case of snaggletooth.

Snaggletooth on a handsaw is usually the result of bad amateur filing attempts. The teeth come out far from even and the tooth heights are up and down all over the place. Not the thing for the smooth cut a cabinet maker is looking for!

The cure for snaggletooth is file, joint, and then refile. The first filing is a fairly aggressive filing that starts to clean up the tooth shapes and gives as much definition to the teeth as possible so they don’t disappear when jointed.

After the first filing, the teeth are jointed using a saw jointer and a flat file to knock the teeth down to the same height. On a handsaw with this much snaggletooth, I don’t try to get the teeth all perfectly even the first time. This would cost major filing time and waste irreplaceable steel from the blade. Get the teeth jointed to where the saw will work and then improve it more the next time it needs sharpening. The final step is another filing to get the tooth profiles tuned up and sharp and set the teeth. The end result is a sweet little saw that even a finicky cabinet maker could love :).

The second saw, from the same cabinet maker, was a German made straight handle dovetail saw, filed in a repulsive “combination” pattern. Combination saw teeth stand the points straight up with no rake. This pattern is intended to both rip and crosscut but is inferior (in my opinion) to a real rip filed or crosscut saw.

The request for this saw was to file it true rip, not a particularly difficult request, since the blade filed fairly easy. Since I was reshaping the teeth anyways and since I knew the customer also used Japanese saws (which cut on the pull stroke), I gave him the option of filing this one to cut on pull as well. I filed an excellent true rip pattern raked toward the handle and the saw cut my test yellow birch just fine.

I have no idea if I managed to beat the fancy pants Japanese saws, but this was a great way to save a couple of nice old saws and give the customer exactly what he needed.

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