Thread: Straightening warped tang

Originally Posted by Deckard

Yes, have thought it over. It's a custom I heat treated today, I had to improvise as tongs are broken. This could work but feel heat is the least risky option. Charlie Lewis has used something called la co heat bloc and a blow torch. Not readily available in the uk.

Joe

Lately I have been doing the process without the heat block paste. I have been using a big vise for a heat sink and am careful where I point the torch. I am heating the tang to dull red then bend. I have had good luck as long as I am mindful of where the torch is pointing.

Try it on a scrap razor, you can see by the colors where the heat is going and where the vise will stop the heat. As soon as it is bent I grab it with pliers and cool it off in water.

I think if you try it without the heat block on a scrap razor you will be surprised how well you can control the heat.

Charlie

I agree with Charley here. The large metal mass will give you enough heat sink to get the job done and careful where you point the torch.

I'm not sure what it is called in the UK, but heat stop is just refractory mortar. It doesn't actually stop the rest of the blade from heating up, it just doesn't crumble into dust at high temperature.

I would try the three pin pressure method in a vise first - even if it is heat treated. If that doesn't work then go to the torch with the tang clamped vertically in the vice.

Originally Posted by spazola

Lately I have been doing the process without the heat block paste. I have been using a big vise for a heat sink and am careful where I point the torch. I am heating the tang to dull red then bend. I have had good luck as long as I am mindful of where the torch is pointing.

Try it on a scrap razor, you can see by the colors where the heat is going and where the vise will stop the heat. As soon as it is bent I grab it with pliers and cool it off in water.

I think if you try it without the heat block on a scrap razor you will be surprised how well you can control the heat.

Charlie

Thanks Charlie,

Tried this today and it worked a treat, I just went for it.
I found it's also feasible to make a water jacket for the blade portion out of doubled up tin foil though I didn't try it.

Joe

I've heard of people using a potato as a heat sink! Haven't tried it myself though.

I'm with Charlie on this one. I 'd try the vise and sandwiching the blade between two fairly healthy pieces of aluminum or copper as either will absorb heat faster than steel.

I used to pull the surface case hardening on Springfield rifle receivers for drilling scope mount holes for the screws by heating a piece of copper tubing that was pressed against the surface of the receiver rings. I'd heat the copper red hot with a torch and it would pull the case hardening in an area the size of the copper tubing. Made it a LOT easier to drill.

You could probably by a foot or so of 3/4" copper tubing, cut it into 1" lengths and then smash them flat with a hammer. I'd think a couple on either side of the tang and then tightened down in the vice would give you a good heat sink provided you didn't get crazy and heat the whole tang red for any length of time. Might think about wrapping a wet cloth around the blade as well and watch for steam. The wet cloth will also act as a heat sink and help protect the blade.