Thread: Any fix for a broken tang?

How about micro-welding? Check out the samples here Micro Weld America - Laser Welding Samples

On the farm we had the drain plug on the transmission housing of a truck get broke off when the truck was run over a hidden stump. I can't for the life of me remember the name of the epoxy we used, only that it is a high-heat tolerant automotive epoxy. We glued the spout back on, and it held up until we got rid of the truck 2-3 years later. There are some seriously seriously seriously strong epoxies out there if you are willing to sacrifice a little bit of aesthetics.

I have never used this stuff: Epoxy by the Leading Epoxy Manufacturer | WEST SYSTEM Epoxy but I would imagine marine-grade epoxy has got to be able to take a serious beating.

What I would do if this happened to me is a little JB Weld magic. If you drill matching holes lengthwise into the tang on either side of the break (as in, drill a hole into the broken surface), a small bit of metal rod can be glued in to help hold the two sides together, and add sufficient strength and stability.

I would try some kind of glue suitable for metals. No big forces are involved, so I don't see why it shouldn't work. If you do it right, I won't come apart ever.

I had this happen to me today.
as a quick & easy fix, I have bought some loctite 435 (stronger, faster, and cleaner than JB-weld)

tested it by knocking the tang of the razor against my desk while holding the spine in my hand.. it held.

it was roughly 30 euro ex VAT for a small bottle, but it WORKS! (also works for scale materials like G10 if you ever want to experiment with a pinless design for the wedge) -- I have a bit of a GAD too :P figured this was an excuse to go all-out.

I think i'm still going to put some small TIG welds on the blade just because.
this should be precise enough to let me spot weld the top & bottom of the tang while the blade is submerged in a cup of water without losing any of the important temper, or the stamp.

then file the notches back in & good as new, visually there's a hairline crack, but mechanically it's good again for years of use to come

the fun thing about tangs breaking, just like with nicks, it's a very clean break so the parts fit back together nice & snug.

Bingo!!! Red is right. A guy who is good with a laser welder can fix that and never get it hot enough to hurt the temper (Never get it too hot to hold).

I have a friend who has pulled my bacon out of the fire a couple times on projects where things needed repaired on a gun or knife. When he was don you could never tell anything had been done. Yes a good laser welder can weld it all the way through.

Ray

+1 on the laser welder.
Those things are used to seal pacemakers.
The laser hits only the seam of the lid, which instantly melts, seals and sets.
All without so much as raising the temperature of the rest of the piece.

sadly though, I don't imagine laser welds to be cheap.. :/
nor very easy to locate :P

To be honest, the only reason I would be able to get it done if I really, really needed it is because I know a guy who writes software for interfacing with those lasers.
And he could do this after hours if I asked him.

If I had to find a commercial avenue for doing this (arguably custom and 1 off) it would likely be prohibitively expensive.

I recently fixed one with duct tape.
If you don't look really close, it blends right in and you can barely even tell it's there.