While the handle is in the varnishing stage, I’ve been worrying about how to approach the sawplate for the new saw. Being the cheapskate that I am, I have been considering using the plate from this thing that I picked up for a song and a dance some time ago:
The basic shape is right, but of course, I’d cut the tip off to make it look halfway normal, mill off the teeth, and cut new ones, and do whatever else is necessary to get it fit on the handle.
The trick to all of this is the thickness of the plate. It’s kind of a tricky business, because all of the old saws were taper-ground, and you won’t find a cheap saw these days that is. So I’d be giving that up, but I don’t have any old saws that I can cannibalize anyway.
Furthermore, until now, I really didn’t know the thicknesses of any of the plates that I was working with; I was only able to sort of guess by looking at them. Well, that all changed when I finally got off my butt and bought a micrometer. Why I didn’t get one before, I’ll never know. It’s really taken a lot of the guesswork out of a lot of stuff.
I’d been wondering about this because I’ve got saws that turned out in certain unexpected ways due to this, and I really didn’t know about it before. For example, my crosscut carcase saw works wonderfully, but a rip version of it didn’t turn out the way I wanted it to. The plate on those two saws is .0263″, but you’d really want something more like the 0.020″ thickness found on most dovetail saws.
What’s .0063″ of difference? Well, one way to think about it is that it’s 31.5% thicker, which is pretty significant. In theory, you’re cutting 31.5% more wood, and so it’s 31.5% more work to do it. (This does not hold for a crosscut saw, where you are slicing fibers out instead of scooping shavings.) You can also look at it visually; take a look at the following image that I just cobbled together as a PostScript program:
The difference between .020 and .0263 looks pretty striking here. These thicknesses are at the cutting edge. I have the measurements for the tops of the saws that are taper ground, but I’m going to set that aside for the moment.
As you might have noticed, I put labels on this image. Of course, after I got my micrometer, I obsessively measured all of my saws. I don’t have a Kenyon saw, but it’s listed here as a representative for a big tenon saw (the Wenzloff versions have .025″ plates).
There are some surprises, such as that Stanley dovetail saw with the gents handle. This is a relatively new one that I picked out of a basement. I never bothered with it because I already had the Crown equivalent (.0205″), but you can see that it’s quite thin! This is the saw featured in Korn’s book, and it should be pretty obvious that if you’re willing to learn how to sharpen it, it will give you experience with a thinner plate and should work just fine. It’s no wonder he has no trouble recommending it.
So getting back to the question at hand, is the lovely “Kobalt” plate going to work? I think I’m going to give it a shot. It’s about 16% thicker on its cutting edge than the original that I’m working with, but that doesn’t seem that bad (and some of this thickness may be lacquer). The thickness of the original is a little unusual anyway; full-size saws are about 33% thicker. The only blade I have that’s close is my frame saw blade (0.029″), and, er, that’s not gonna work.
Then there’s the matter of taper-grinding. Should I try this? I’ve got sort of an idea of how I can do it without a power tool (although if I were sane, I’d ask to use someone’s belt sander). Would that warp the plate? Hmm.