Thread: Knifemaking photo-essay (6) Fitting the handle slabs

The previous post in this series was: https://www.nzhuntingandshooting.co....-guard-105186/

Preparing the handle slabs.

I often use Wenge (millettia laurentii) for knife handles. This timber is hard, dense, has good dimensional stability, has a pleasing appearance, and it glues well with epoxy.

1) Cutting an 8.5 mm thick slice from a 250 mm long slab of Wenge.

2) I make my knives with a slightly forward-angled guard. Here, I’m measuring the angle (which was 3 degrees).

Using the drop saw, I make a 3 degree cut at each end of the Wenge slice, then cut it (more or less) in half.

3) The blank and its two handle slabs. Note the top slab has a circled “L” – this slab is for the left hand side.

4) I set up the slabs so the grain will be angled as shown here (the top of the image is the top of the knife). Thus, it’s important to keep track of which slab is for which side!

1) Flattening the side of the slab that will be glued to the tang. To do this job, a disc sander is better than a belt sander.

2) Angling the front of the slab. The dovetail cutter cuts an 11 degree internal angle into the guard, and add one degree for the taper. I set the work rest to an angle of 12 degrees, and grind the front of the slab. Then I place the slab on the tang with the front butted up against the guard, and look to see if any light passes between the slab and the guard. If I can see light, I alter the angle of the work rest as required, re-grind the slab angle, and check the fit again. I continue this trial-and-error fitting until I can’t see any light between the slab and the guard.

3) Butt the angled slab firmly against the guard, and clamp it onto the tang. The small vice-grip clamp with swivelling pads is invaluable for this job.

4) I made this jig to ensure the holes for the knifemaking bolts will be perpendicular to the flat of the blade. The blade is clamped in the jig, with the butt end of the clamped-together slab and tang supported by the cylindrical brass screw (indicated by the pink arrow). I then drill two 1/8” holes though the slab.

1) With the handle slab still clamped to the tang, unclamp the blade, turn it over, and again clamp it in the jig. The handle slab is now facing up. Turn the cylindrical brass screw until it supports the butt. I now counterbore* the 1/8” holes using a 5/16” piloted counterbore (indicated by the pink arrow). I’ve set up the drill press so that the thickness of the timber between the bottom of the counterbored hole and the tang is about 2.5 mm.

* a counterbore bit produces a flat bottomed hole.

2) A top view of the jig showing the clamped blade and the handle slab with counterbored holes.

I make my own knifemaking bolts.

3) Cutting 5/16” diameter round brass rod into sections 7-8 mm long.

4) Centre drilling a section of 5/16” rod. I also break off the edge with a file.

1) Drilling a 7/64” (2.78 mm) hole in a section of 5/16” rod.

2) Tapping the hole M3.

3) All the parts are ready. Note that I’ve cut away some of the excess timber of the handle slabs. The screws are M3, stainless steel, with a Phillips head.

4) Trial fit. Assemble the parts, ensure the Wenge slabs are butted up firmly against the guard, and check everywhere for correct fit. Then I sand the ends of the handle slabs so they are flush and the same length (the reason for doing this will become apparent shortly ... ).

The parts are nearly ready to be glued together. I wash the knife blank with hot soapy water, rinse it with hot water, and dry it with a towel. I also ensure my hands are clean.

I dry-sand both sides of the tang half a dozen times with 80 grit abrasive cloth, followed by cleaning with a meths-soaked tissue. I then wait until the meths has evaporated.

From now on I make a point of not touching the tang with my hands.

I used to glue up my knives with Araldite epoxy, but the large packs seem to have disappeared from my local Bunnings. So now I use a 4:1 mix summer-cure laminating epoxy mixed with glue powder. I’ve been using it for years, and it seems to work fine.

Smear glue over a handle slab, and leave it for a couple of minutes so the glue can soak into the wood. Also smear glue over the corresponding side of the tang, making sure it’s fully “wetted”. Don’t forget to put glue on the angled front of the slab. Also, ensure the guard’s internal angle is smeared with glue.

Place the tang on the glue-covered slab.

1) The image shows the tang sitting on the glue-covered right hand slab, the left-hand side of the tang smeared with glue, and the tang’s lightening holes filled with glue. Note – I probably added a bit too much glue powder to this batch of epoxy!

2) The glue-smeared left hand slab is placed on the tang. Remember to put glue in the counterbore holes. Note that glue is oozing out of the guard-slab joint (as it should).

3) Fit the knifemaking bolts and gently tighten them. I now place the assembly into a home-made clamp that’s designed to push the slabs firmly up against the guard. This is why I sanded the ends of the slabs flush – so the clamp can exert even pressure on both slabs. Moderately tighten the clamp, then tighten the knifemakers bolts. You can see I also lightly clamped the butt end with the blue clamp.

4) The glued up knife. I allow at least 24 hours for the epoxy to set; I gave this knife 48 hours.