Wednesday, July 16, 2008

In my (occasionally)continuing educational series

on making knives, here is the basic procedure I use to set a short tang into a grip.

For this I took a piece of curly maple, measured out a little longer than I thought the grip would end up, and a little wider(you will be cutting it down, and it's much better to have excess to remove than to have not enough); this piece is right at 1" thick which is more than enough for a small- and some medium- blades.

I first hold the tang against the piece in the position/angle I'll want it, and outline it. Then I use a square to draw lines marking the centerline of the wood, and two lines to mark the edges of the tang on the end I'll be drilling, visible on the block in the picture below*. These lines let me align the drill bit with the desired lines.

At the drill press I put the bit in, place the block in a vise, adjust the height so the big has just a touch of clearance above the wood. Then turn the bit down until the chuck almost touches the wood and line the bit up with one of the lines:I use a brad-point bit: it has a center point that makes it easy to get it on the line, and two cutting spurs on the edges that give a nice, clean hole. This is shot from the side, and you'll notice the block is tilted just a touch so the bit runs straight along the line. When it's adjusted, lock the block tightly so it can't shift, raise the chuck, then adjust the block so the center spur is exactly on the centerline you marked, and the outside of the hole will be along the tang line. Then turn the press on and drill; go in just a bit, back out to clear the chips, and repeat until you're all the way down.
Then repeat the process for the other side.

I usually put the bit as far into the chuck as I can and still get good depth to the hole; it helps keep the bit from flexing to the side. After drilling both sides, I
take the block out of the vise,
adjust the bit as far out as it will work, or a touch longer than the tang, whichever comes first,
and drill the two side holes to full depth. For this I usually turn the press on, and carefully slide the block up onto the bit, one hole and then the other. When both are drilled tap all the dust out, then put the block back in the vise. This time you carefully drill on the centerline to cut out as much of the wood between the holes as possible. When all you can do is done, I once again take it out of the vise and- very carefully- move the piece back and forth, using the bit to mill out what's left. When done, you should have a tapered hole just about right for the tang to fit into with little slop in the fit.
If the fit is a little too tight, two things you can do. The best is to get a coarse round file and grind flats on two sides; that'll give you a narrow file that will fit into a slot and allow you to widen it to either side. The other way I only use if the hole is a little too shallow and the bit won't reach far enough to deepen it:
clamp the blade in a padded vise with the tang sticking out, and use a torch to heat the very end to a nice red, then push the block on. Making very sure you push it on proper way. It'll burn the hole the needed bit deeper, with a fair amount of smoke and stink**.

A while back I shot a sequence showing fitting a brass guard to a blade. In this case I cut and fitted a piece of antler(pictures of that to come on the other blade and grip I've got to work on). In this case I mixed up some epoxy, put some on the blade/guard juncture so they'd be locked together and sealed(no moisture or whatever can get in that way), then epoxied the blade and guard to the grip.

Shaping the grip was mostly done on the belt sander. I used a pretty coarse belt for this as there was a lot to remove. You can do the same thing with rasp, coping saw and sandpaper, this is just faster. Be aware that 'faster' means you can take off a LOT more material than you may realize a LOT faster than you think. A sharp belt cuts both faster and cooler, and clogs less than a dull one.

I only have a couple of pictures, as trying to do this with one hand and shoot with the other is tricky. One of these days I'll get daughter or someone over to help shoot this. Basically, I cut the sides to a little over the desired thickness,
then shape the top & bottom
Then rough in the rounds all the way around
Once at this point I switched to a finer belt to smooth things, then went to emery cloth(comes in 1" wide rolls) to finish it. Clamp the blade in a vise, then use a shoeshine motion to round and smooth things. You can also, if need be, use files and regular sandpaper to finish it. I'll take a couple of more pictures of this piece when it's done.

*The picture I took of the block all by itself, markings visible, turned out badly(very), so you'll have to do with this for now.

**On fitting a grip to a long tang that goes all the way through, some makers drill and rough out the hole, then heat the tang and burn it in so they have a tight fit along the whole length.

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