Thursday, January 10, 2013

A Knife for John

So we continue to catch up with our Christmas projects, which can now be revealed. I made a knife for John. It is a big step. I am going from hacksaw blades (or even a cut-up circualr saw blade) to an old file as raw material. As I found out, there are some bumps in the road, although the principles are exactly the same.

 I started out with a worn-out file. It was annealed overnight in the woodstove. In retrospect it was not enough! But OK, live and learn. I have, since I did this, gotten a book as a Christmas present. It is a book entitled Hardening, Tempering and Heat Tratment by one Tubal Cain, a pen name for the late T.D. Walshaw. You can google on it faster than than I can type in a long ISBN. Priceless. Anyway, I started with this semi-annealed file.
I then ground down the blade to what I thought was a nice shape. I also gave the thing a few touches with a file. This is a full-tang knife. So to handle it I will have to drill holes in the tang to accept the handle. The handle is a more or less straightforward piece of woodworking. I happen to have a few priceless pieces of applewood. I turned them inside out, pith outward, because it looks much prettier.

Now we have to attach the handle to the blade. For this kind of thing we want rivets. I happen to have a bunch of brass rods which are intended for welding (actually brazing) . But I use them for rivets. You cut them a bit longer than they need to be, say 1mm longer, and then whale the daylights out of them with a hammer. They will spread out and hold your handle firmly. Needless to say you have drilled matching holes in tang and handle. These brass rods may reappear again in another role. Stay tuned.

The rest of the knife is the business of honing.  I've been before there on this blog! Try the "sharpening" label. And we must, of course, apply linseed oil to the handle.

Main lesson learned from this project. As if I didn't know it theoretically. The bigger the mass the more heat it needs to work it.  Tempering this thing was a bear. From the book I cited above, I now see what I should have done. However, ignorance is bliss. I got away with it, and it is a very nice knife indeed.

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