How to make this handle slot?

[KevinLycett]

I need to replace this breadknife handle. But the blade is tapered from its spine to its cutting edge, and the slot is tapered likewise. The slot also doesn't go full width or full length of the handle. It stops short. How the heck do you do that? Can anyone suggest how to make a slot like this? Or a workaround? I'm stumped.
.

 

[baldkev]

Im not suggesting this would be easy, but multi tool? You can set the depth on the blade using tape, you can set a straigth edge by clamping the handle to an old box section level or similar.... its the taper thats difficult.... but maybe a strip of electrical tape at the bottom of the box section to slighty aim the blade? You'd have to then put the box on the other side of the cut line and go again to get the tapered slot.
Maybe practice on 2x1 batten first. In fact, youd be best doing the slot while the handle is still a blank, then put a packer in the taper, and cut your handle shape.

 

[Droogs]

band saw with the handle held at an angle to give the taper and then cleaned out with a 4mm mortice chisel. Or if you don't have a bandsaw then use a carcass/dovetail saw. Pretty basic hand tool angled bridle joint really.

 

[KevinLycett]

band saw with the handle held at an angle to give the taper and then cleaned out with a 4mm mortice chisel. Or if you don't have a bandsaw then use a carcass/dovetail saw. Pretty basic hand tool angled bridle joint really.

How can I use a bandsaw, or in fact any saw, when the slot doesn’t continue right through the wood in either direction? In other words it stops short in both depth and length.

 

[redhunter350]

Most knife handle scales are two pieces of wood then glued and riveted to the blade and shaped in situ. If done carefully the joint will not show. I woukk on d remove the old scales and look at the hilt you may find it’s not tapered?

 

[paulrbarnard]

You haven’t shown us a picture of the tang so I’m guessing but if it is tapered then cutting a straight slot with a saw at an angle is probably all you need to do. No need to taper the slot. You then hammer the tang into the new handle. The width ways taper pushes the wood out ensuring a tight fit.

 

[Ollie78]

Make the outer shape then cut it in half, make the rebate and glue it back together before riveting it back on.
Use a thin fine saw to separate it and it will be quite hard to see the join.

Ollie

 

[Jacob]

That'd be machine cut with a shaped for purpose small radius circ saw or spindle cutter.
The traditional hand tool for cutting a slot like that is the mortice chisel. There are a lot of them about down to about 1/8" which means there must have been a lot of slots being cut - not quite sure where or why - I imagine metal moving parts in wooden cases, clocks, cameras etc.

 

[Rorschach]

Very difficult to do without the right tool for the job. So make it as a 3 piece handle, two sides and a piece of wood the same thickness as the blade to make up the gap around the tang. Done it many times myself and can be done almost invisibly if you are careful but personally I try and make it a feature and use a contrasting material/colour.

 

[KevinLycett]

Most knife handle scales are two pieces of wood then glued and riveted to the blade and shaped in situ. If done carefully the joint will not show. I woukk on d remove the old scales and look at the hilt you may find it’s not tapered?

This *is* tapered and is whole - not in two parts. That is why it is so difficult!

 

[KevinLycett]

Very difficult to do without the right tool for the job. So make it as a 3 piece handle, two sides and a piece of wood the same thickness as the blade to make up the gap around the tang. Done it many times myself and can be done almost invisibly if you are careful but personally I try and make it a feature and use a contrasting material/colour.

that’s interesting! It’ll still be very hard as the slot is tapered. But definitely looks easier than trying to carve the slot out. Thanks.

 

[KevinLycett]

You haven’t shown us a picture of the tang so I’m guessing but if it is tapered then cutting a straight slot with a saw at an angle is probably all you need to do. No need to taper the slot. You then hammer the tang into the new handle. The width ways taper pushes the wood out ensuring a tight fit.

Wouldn’t that split the wood at the end of the slot?

 

[KevinLycett]

That'd be machine cut with a shaped for purpose small radius circ saw or spindle cutter.
The traditional hand tool for cutting a slot like that is the mortice chisel. There are a lot of them about down to about 1/8" which means there must have been a lot of slots being cut - not quite sure where or why - I imagine metal moving parts in wooden cases, clocks, cameras etc.

The slot is very narrow but deep. It tapers from 2mm to 0mm and is 24mm deep. Is there any chisel that could cut that?

 

[KevinLycett]

Most knife handle scales are two pieces of wood then glued and riveted to the blade and shaped in situ. If done carefully the joint will not show. I woukk on d remove the old scales and look at the hilt you may find it’s not tapered?

Yes that’s a great point. I’ve been avoiding taking the old handle off until I’m sure I can replace it. So… deep breath!

 

[Rorschach]

that’s interesting! It’ll still be very hard as the slot is tapered. But definitely looks easier than trying to carve the slot out. Thanks.

That's why I suggested the 3 piece method. You taper your shim/fillet/filler piece to continue the shape of the tang and just have the side pieces perfectly flat. This way you only have a small piece to actually shape properly and if you mess it up you have only wasted a small sliver off wood and can try again. Once you have it right use plenty of epoxy and glue it all up and you will get a perfect fit.

 

[Jacob]

The slot is very narrow but deep. It tapers from 2mm to 0mm and is 24mm deep. Is there any chisel that could cut that?

No, I was talking about slots in general. Yours would be machine cut with a purpose designed cutter.
But if you were going to do it by hand something filed down to work like 2mm mortice chisel would start it, followed by saw cut. Or start with a saw cut and widen it?

 

[KevinLycett]

That's why I suggested the 3 piece method. You taper your shim/fillet/filler piece to continue the shape of the tang and just have the side pieces perfectly flat. This way you only have a small piece to actually shape properly and if you mess it up you have only wasted a small sliver off wood and can try again. Once you have it right use plenty of epoxy and glue it all up and you will get a perfect fit.

I’m also wondering about glue. Try though I might this knife often ends up in the dishwasher. Do you think epoxy would cope?

 

[Rorschach]

I’m also wondering about glue. Try though I might this knife often ends up in the dishwasher. Do you think epoxy would cope?

If anything will it will be epoxy. Obviously you will need to pin it as well.

 

[--Tom--]

Have done a few of these and each time wished I was using a slitting saw to make the groove. It’s doable with careful hand sawing and a thin chisel, but you’ll inevitably have a gap right at the end of the slot. Using a dark wood like ebony will make the filler less conspicuous as you can tint the glue black or use a black super glue.
The original will use cutlers rivets- these need accurate drilling to work well and also good measuring to ensure they close evenly- adds a bit of fun to the glue up if you go that route.

If it were me, I’d shun wood and cast homemade micarta around the tang. Will give no visible joint and a material that’s better able to stand up to dishwasher (ab)use.
You could do something similar with thin slices of wood - like pakkawood which is used often for handles and is similar to ply in construction but unidirectional.

Another option would be to reshape the tang to fit a hidden tang handle - but they are often economical with the steel and generous with the drilled holes so not enough to play with - but you may be lucky once you pry the old one off.

 

[--Tom--]

Edit to add a link to thread on how to go the casting route if you fancy that:

https://edgematters.uk/thread/35933-home-made-mycarta-knife-tutorial/?pageNo=1