Let’s make a saw…part 1

A few months ago I found an elderly lady down the street having a yard sale with a bunch of old saws. In addition to some good users, I got a turn of the century Disston #12 with the blade all but used up….so much that the plate was coming to a point. So, I basically bought it for the remarkablly nice handle, which was in near perfect shape…

These old #12 handles from the golden age of Disston are such gorgeous works of art themselves I hate to see them retired just ’cause the saws used up, so I decided to make a project out of it….and these projects are the most fun…turning old saw parts into new saws!

If you’ve never undertaken making a new saw plate don’t sweat it…its very simple and straight forward when you use a donor plate from another old saw. I always haunt yard sales and flea markets for saws and donor parts of saws, and keep a little cache of saw stuff on my parts shelf. For the new saw, I’m thinking this handle will go nice with a 22 inch plate with 8ppi. I want it to be a traditional pattern with straight back and nib, but I have no donor paltes like that, so we’ll have to cut and file one from a bigger plate.

When identifying a donor plate, there are a few things to look for in quality. Because this is the handle from a #12, which was the top of the Disston regular production line, I want a nice plate for it…preferably taper ground and well smithed. So, the $64,000 question is, how do you find a quality saw plate from the jumble of rusted crap at the flea market? If the saw has a nib, or is a skew back pattern, it can be a mark of quality as these required extra manufacturing steps and added cost to the saw. But even without these obvious characteristics, you can perform two tests to any saw to gauge its potential quality. Now, while these little “tests” as I called them are not fool proof, or gaurantees of quality, taken together they can be a good start.

So, the first thing we look for in a good saw plate (whether or no you want to use it as a donor, or just want to know if its a good quality saw) is a taper grinding. Taper grinding allows the saw to work without binding in the saw kerf and is a hallmark of well made saws. It was standard on all quality saws of yesterday and it added quite an expense to the manufacturing process. To test for it, we use the callipers to take thickness measurments at the toe along the back, at the back next to the handle, and at the heel along the tooth line. The plate should be thickest along the tooth line at the heel (under the handle), and should be its thinest at the toe along the back (at the point). It should be of a median gauge along the back. Here’s a pic of me measuring along the back…

You will indeed need a set of dial callipers accurate to 0.001 to perform the test (don’t worry, thanks to those industrious Chinese, you can get them cheap…mine were about $15 at Harbor Freight) This plate measures 0.040 inches at its thickest, tapering to 0.036 along the back and 0.034 at the toe….a nice tapering indeed.

So, now we know its tapered, how about smithing? What the heck is smithing? Well, its the hammer work that goes into a saw plate to make it tensioned and true and you can perform a neat little trick to hear if a saws been well smithed. Yes, I said, “hear” because when well smithed, a saw makes a pleasant tone if struck a certain way…kind of like a tuning fork. Remember those from music class? (I do….another recurring nightmare from junior high) This trick is a little harder to show and write about…you really need to see someone do it in person…my friend Josh Clark taught me how to do it…thanks Josh! Basically, you grasp the saw in your hands with one hand on the toe and the other at the heel and simultaneously tap the plate with your thumb while you bend the plate into tension. It looks like this…

When you do this, the best saws sing a crystal clear note that sounds like angels on high (well, at least that’s what they sound like to me, but I sleep with my saws so I’m weird) Anyone can learn how to do this trick…you just need to see it done (I’d be happy to oblige, but I would require at least a pint of Ben N Jerry’s in return) And this saw has a nice, clear, sweet tone so we’re in luck!

So now we know we have a donor plate worthy of our nice #12 handle. The next step is to rough out our new plate and grind the new pattern.

We’ll get to that shortly….stay tuned….

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Published in: on October 28, 2010 at 5:48 pm  Leave a Comment  

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