Hey Y’all, 

Apologies if this isn’t the right thread for this post but I have what may be a silly question. I’m trying to find a small saw to use to hollow out handles for through tang knives. Any idea on the name of this? I tried searching keyhole saw but that’s mostly for drywall. If you know anything let me know!

You might try looking at mortising cutters.  Though most are for "thicker" cuts than a tang, there are some finer sizes available when you dig a bit.

Or grind your own from a power hacksaw blade---might make 2 a cut on pull which can be very thin or a cut on push which needs a bit more heft.

They are called a tang broach. I made this one from a reciprocating saw blade, easy to do.

That’s exactly what I need! Thanks y’all!

Echo that, IFC! I'm making a couple of these tomorrow! Thanks for lighting the spark!

Does this mean I don't have to mess with the coping say anymore?  Tang broach it is. Thanks again. 

Frosty The Lucky.

The broach works really well for hidden tangs too.

Excellent. For hidden tangs, it should beat heck out of the flame/smoke/fire/stink/char & burn method, which I never liked, and the broach will still allow carving a "slotted" tang hole. I have never trusted epoxy to properly bond to charred wood, although haven't had any failures (yet).

To get the epoxy to bond better to a burned in tang,would roughing up the tang  a bit with a file and gently sanding away the char in the handle material taking care not to remove too much material help?  I don't trust epoxy on its own either. I feel much better using epoxy and a mechanical fastener. I haven't tried making pins from the same material as the handle in a hidden tang to disguise the pins. I might have to give it a try. Example making little pins from walnut for a walnut handle. Hmmmm.

Pnut

Edited October 13, 20196 yr by pnut

Heat softens the ligum in wood, if you stay below the char point once it cools the ligum sets back up. For tools a square or rectangular tang with a hammer finish will be nearly impossible to separate.

That's what I was thinking with roughing up the tang surface. I thought it would have a slightly irregular surface to bind to. I didn't consider a hammer finish doing the same thing. Thanks.

Pnut

Charles is right about this.  Ideally you have a tang hole slightly undersized and black heat the tang so that it MELTS (not chars) it’s way in.  Then the heated and compressed wood fibers cool to form a very strong socket for the tang while the resins in the wood (which are a natural form of ferrule cement) glue the tang into place.  Done this way, the hidden tang is at least the equal of a through tang for security.  I generally make a tapered square tang and melt it into a step drilled round socket.  For tools that will see rough use, I’ll carefully fill the slight gaps along the flats of my tangs with a thin glue filler (usually some version of cyanoacrylate).  If you use the burn in method, IMO, it’s best to use an undersized model of your tang and then follow up with a tang broach or drill/mill bits to create an overly tight tang socket that will melt to a perfect fit during the hot fitting process.  This requires a bit of experience to judge as softwoods will compress a lot more than hardwoods while being hot fitted.  Each wood species reacts a bit differently.  A little practice will get you there though... and the results will be well worth your efforts!

Once again, thanks for the further details. I haven't made a lot of tools with tangs but when I do I will put this info to good use. I've only seen it done by literally burning the tang into the material. The hidden tang awl I made I drilled out and filed to fit. I left it at someone's house and it disappeared. I need to make another one so I can finish my apron. I may try to handle it in the way you described Bfn.  Thanks again.

Pnut