My way of doing bolsters on Wa handles.

billyO

Well-Known Member
I was going to post this as a response to this, (https://knifedogs.com/threads/mcleish-kith-2020.51714/post-413121) but thought it would be better to start a new thread.

I typically use 1/4"-1/2" thick ebony as bolsters on my knives, but anything would work. On my latest knife, the spine was 0.070" at the heel, tapering to 0.060" toward the edge (full face flat grind), and the tang thickness was 0.055".
Mark the centerline of the bolster
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and drill 0.050" holes at either end of where the tang would be on the center line.
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Use an X-Acto knife to scribe lines connetcing the outer border of where the line of holes will go (this helps to keep the tiny dril bit in line). I will actually carve out a little notch here to remove a sliver like making a mortise in wood.
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Drill a line of holes for the tang. It's hard to overlap here but don/t worry too much about the spacing, because you can always use the X-Acto blade to remove webs as needed. Just make sure they are inside of the scribed lines
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Flip the piece over and use a larger drill bit to remove material on the handle side. Set your drill press stop so that you don't drill all the way through, I leave at least ~3/32" of material. Make sure the holes are small enough not to grind into them when finishing the handle dimensions.
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Use a needle file or something else (I use manicure/pedicure nail files for this. The ones I have are about 0.050" thick) to clean out the hole. Take care that you don't make the slot wider than the ricasso of the blade, then fit up the rest of the handle and glue up.
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The above picture can represent either side or top view of the tang.

** It's important to do all finish sanding and polishing of the face (top) of the bolster before glue up.**
This way allows you to not have to worry about how close the fit-up is for the hidden tang. You do have to pay attention when gluing up that everything is kept square and true to the blade while the epoxy is curing.
I hope that's clear and helpful for some. Feel free to ask questions.
 
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As a side note. Today, I decided to drill the backside out after drilling the 2 end holes but before drilling the rest of the slot with the small drill bit and this worked pretty good. I'm not sure if it made any practical difference, but doing so allowed the smaller bit to not have to drill through as much material, so I'm thinking it helped prevent any wandering of the bit.
 
Great Billy thanks for putting this together. I have some thin damascus blades I cut into hidden tang knives before I realized what I was doing. I was going to just buy some milled guards but I'll give your method a shot. These blades I have are all at about .100 thick. Me and the grandson of a family I was visiting rolled out the billet too thin when the boss (grandpa) wasn't looking. They've still got deep scale, too, so not sure what I'm going to end up with.

I like the idea of cutting both sides of the line with an exacto knife. Seems like it'd keep the wood from chipping out, too. An exacto knife would also still give a deep groove to follow in a soft metal.

This way allows you to not have to worry about how close the fit-up is for the hidden tang.
What do you mean here?
Do you press fit the wood at all? It seems like there'd be some give.

Also, do you use just a regular drill bit?
 
What do you mean here?
I was mainly referring to how the grinding/filing of the tang narrower than the ricassos to make a shoulder goes a long way to making sure there's no visible gaps at the ricasso/bolster junction after glue-up
Do you press fit the wood at all? It seems like there'd be some give.
I try to remove as little material as possible to approach a 'press fit' but don't necessarily shoot for that. I found that with wood, doing (what I would refer to as) a 'true' press fit can cause some wood fibers to get dragged down into the slot as the tang is forced in, and this doesn't leave as clean/crisp fit up. As long as the width of the slot is no larger than any part of the tang, there should be no gap visible.
Everything gets set in place with epoxy at glue-up, which is why I mentioned that you have to pay a little more attention while clamping to make sure everything is true and square.

Also, do you use just a regular drill bit?
Yes, for the most part. I do have some wood bits that I think are called 'brad-point' or 'spear point' (or something like that) that have a sharp guide point for wood that help keep the bits from wandering. I use these for drilling the relief slot from the back side. The point goes into the tiny pilot hole, and I just set the drill stop to where the point touches the table to make sure I don't make the holes/slot any bigger.


One last thing that I do sometimes (not all the time, for whatever reason), is to drill/grind out a bit of the mating surfaces of each piece to make a seamless glue-up easier. Kinda like folks do with scales and full tangs, just make a slight hollow/depression in the middle of the pieces, making sure to avoiding the edges. Then all you have to do is flatten the perimeter or the piece to get a flat plane. I try to leave at least ~1/8" material around the perimeter.
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