Chris Schwarz's Blog

Tweaking an Over-set Coping Saw

When cutting dovetails, I’ve always cleared out most of the waste with a coping saw. Why? I learned it that way in 1993 and am faster with the coping saw than I am with a chisel.

Even though I’ve been dovetailing for almost 20 years, I’m always looking for small things to improve my speed and tighten my fit. This morning while cutting the endless dovetails for this Campaign Secretary I had a thought.

This can be good at times, or a waste of a good time.

One of the annoying things about coping saw blades is that they have too much set. My much-beloved Olson blades are .015” thick but cut a kerf of .025” – that’s .005” of set to each side.

As a result of this extraneous set, it can be hard to drop the coping saw blade into the kerf left by my dovetail saw, which is .020”. The tips of the teeth stop me from dropping the blade to the bottom of the kerf and making an abrupt left turn to saw the waste. As a result, I have to saw out the waste in two sweeps, one left and one right.

This morning I filed back the set on my coping saw blade. I took about five swipes on each side of the blade with a fine mill file. After I finished, the thickness of the blade plus its teeth equaled .017”.

Then I went to work. The blade dropped to the bottom of my existing kerf and I was able to clear the waste of my pin board with only one sweep.

Doesn’t the saw jam without the set? Perhaps it would if I were cutting wet softwood, but in dry hardwood – mahogany in this case – the blade sailed right through without a squeak.

This got me thinking that perhaps I could try to bend out the set in a blade using a metalworking vise like Mike Wenzloff shows in this video I shot.

— Christopher Schwarz

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9 thoughts on “Tweaking an Over-set Coping Saw

  1. Seenya

    I use a jeweler’s saw. It uses scroll saw blades. It has about 3″ of depth but that’s plenty for dovetails. I have stoned a few dovetail saws, though.

  2. hobomonk

    My grandfather used a similar technique to flatten the set on fine toothed saws, like coping saw blades. He would stone the blades. No, not with an heirloom Arkansas whetstone, but with a stone from the Licking River. Under magnification, a stoned, or draw filed, saw blade’s teeth kind of look like a Japanese-style saw’s teeth.
    Just sayin…

  3. zephyrblevins

    I’m a total novice, so please forgive me a potentially stupid question about marking out dovetails. Has anyone ever tried this – let’s say you cut tails first. Make the vertical cuts for the tails, but before sawing or chopping out the waste, use the cut lines to guide your marking gauge to mark out the pins on the pin board. The marking gauge would have to be thin enough to fit in the kerf (maybe an XActo knife) and also tall enough (longer than the width of the tail board), but is there any reason this is a bad approach?

  4. TomS4449

    I just switched to using a fret saw myself. In part due to financial obligations. A new Titanium Knew Concepts fret saw with an Elkhead Tools cocobolo handle. It works swimmingly and I look good doing it !!!
    TomS

  5. mlingenfelter

    That’s one of my biggest gripes with Coping Saws! I’ve been trying to move from a Fret Saw to a Coping Saw, but those wide teeth have been a pain. I’ll give this a try and maybe I can make the move now.

    Mike

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