OK folks about 1/2 of the knives I forge the edge has a twist in it and is very difficult to straighten. It's usualy a propeller or S twist from the point to mid lengh of the blade.
I have heard of using a fork of sorts that slide into the hardy hole on the anvil. And situating the spine in the fork, then use an adjustable wrench and tweek the edge while the blade is hot.
Does that work? What other techniques work?
What say you?
Steve
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Potomac Forge
Is that a twist after hardening or right after forging. If the latter tap it out with the hammer using very light hits. Or use a hard wood mallet while still hot to tap them out.
If the former set up a thick flat piece of steel and some metal clamps. Clamp the blade to the steel with the outside bend of the warp clamped against the thick steel piece. while still hot from the quench apply enough pressure to take the blade to fully flat or with the ends pushed a bit away from the thick piece of steel and put the blade in your tempering oven. With a little practice the tempering and pressure straightens the blade.
I've had a few twists with real deep hollow grinds on quenching. I think it's because I tried to have a finished blade at quench. Not had any problems with flat grinds. Now I leave my hollow grinds a little thicker especial at the edge...Doc
Heat it up, stick it in a vise, and twist it with a crescent wrench.
I'm lucky enough that one of my mentors is a master blacksmith (and a damn fine bladesmith to boot) and his technique for fixing bends and twists in a forged blade is to heat up the spine with a torch to "robins egg blue" whatever that is ;-) and apply just enough tension to where you think your blade wants to end up, and then throw a wet towel (my idea) or pour water over the blade while holding it in that position. I definitely think its a feel thing, but I've done it on four blades now and three of the four came out perfect the first time and the fourth took two tries to be dead straight nuts. Cant argue with the results. The cool part is that you get to feel the blade "shudder" when you throw the wet rag on it (its pretty cool!!)
A friend of mine has kind of a cool setup-he took angle iron, heated it up and put it in his post vise. He hammered down the piece that went over the curved back of one jaw, the other part is pointing down, on the inside of the jaw. Then he took and welded a piece of metal to it and ground it flat. Did one of those for both jaws so the welded on pieces meet smooth and flat (is this making any sense?). When he needs to straighten stuff out, he just sticks it in that vise and tightens it up. Best part is, the angle iron pieces over the jaws just lift off and you can make different kinds (lined with hard rubber, leather, whatever...). Just my inexperienced $.02. Hope you find something that works for you.
Jeremy
Thanks for the responses guy's!
The twists are a result of forging the edge bevels, if mild some times I can frind them, most not.
I got the blade straight after some effort with my small finishing hammer.
Steve
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Potomac Forge