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Guest MPerks89

Drawing out and Edgework

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Guest MPerks89

Hi,

 

I've just forged my first two knives, and they came out very roughly shapen and too thick. How do you draw out the steel correctly?

 

I've been forging at a bright orange heat (that's as hot as my forge gets) and as much as I hit the steel, it doesn't seem to do anything. I had to pound on a leaf spring with an 8lb sledge hammer for 3 hours before I got a flat leaf spring. And now I can barely move my arm.

 

I've read "New Edge of the Anvil" and all of Donn's website (as well as numerous others), but it doesn't really address my issue. Any tips for a beginner?

 

Thanks,

Marc

 

---------------------------------------------------------

 

As a sub-topic, can edges be forged, or must they be ground?

Edited by MPerks89

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Use a hammer with a smaller diameter head. An 8 pound sledge is good for welding billets, breaking down barstock, and gentlly straightening blades before heat treatment, - not shaping. Use a 2lb drilling sledge or a 32 oz ball peen hammer for shaping blades. The lesser diameter head is more effective because the force of impact is concentrated in a smaller area; and your arm won't get as tired. As your skills improve, forging edges will save you a lot of time grinding. Just don't get the edges too thin (less than 1/16th) or you may get some cracking during heat treatment.

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Guest MPerks89

Excellent, I have one of those as well.

 

But as they say in Switzerland: I'm working way too hard.

Edited by MPerks89

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That's really odd. Just out of curiosity, what thickness leaf spring are you using? Normally, at an even orange heat, I straighten out 1/4" thick stock with about a half-dozen or so smacks with a 3lb hammer.

In response to your other question, edges indeed can be forged. However, some grinding will be needed to finish.

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Guest MPerks89

The leaf spring is about as thick as my index finger (I don't have calipers).

 

I figured I was working harder than necessary; it took me about four hours to flatten it out, during which span I probably heated it at least thirty times.

 

I've now tried using a 2lb cross peen hammer. It's slightly easier, but not much.

 

Perhaps this is because I'm using a cast iron anvil? I'm a full time high school student so I don't have any chance to produce income.... that anvil was the best I could afford.

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Guest MPerks89

I just found this chart online.... turns out I was using the wrong term. I was forging at "light cherry" heat, not "orange" per se. It looked orangish to me, but I guess you bladesmiths have your own lingo worked out....

 

The question now becomes, how do I get my forge hotter?

 

And what is minimum forging heat?

post-1435-1111961339_thumb.jpg

Edited by MPerks89

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I don't think well in degrees C, so here is the same chart in degrees F

 

Faint Red

9500 - 10500F

 

Dark Red

11500 - 12500F

 

Dark Cherry

11750 -12750F

 

Cherry Red

13000 - 14000F

 

Bright Cherry

14750 - 15750F

 

Dark Orange

16500 - 17500F

 

Orange

17500 - 18500F

 

Yellow

18000 - 19000F

 

Yellow/White

OVER 20000F

 

1) I think you are forging at too low a temperature, you should be in the Dark Orange to low Yellow range, reducing your temp as you get closer to your final heats.

 

2) "The leaf spring is about as thick as my index finger ". I don't know about your fingers, but on mine that close to 1/2 an inch, say 12-13 millimeters. That is a lot of stock to be moving around. I like using stock closer to the size I want the finished piece to be. 1/4 inch (5-6 mm) is good, as your technique improves 3/16's works. Unless you are doing some kind of integral bolster, 1/2 inch is too thick.

 

3) What kind of forge setup are you using. Venturi, forced air, gas, coal, charcoal, laser induction plasma? Whoops, not supposed to talk about that last one :D

 

In a gas forge there 4 important factors, fuel flow, air flow, interior size and insulation. You want to match the fuel, air and size, and get the best insulation you can get. With Kaowool you get a big increase in efficiency by using ITC100 or Satanite. If you box is too big, or not well insulated or has too much thermal mass, then it can take a long time to get up to heat, or perhaps never get there.

 

Ron Reil has everything you need to know about Venturi burners on his site, my mod of Don's burners works good with enough fan behind them.

 

These days I forge with a 4lb cross pien, mostly in 1/4 stock, fairly close to shape. You still have to grind, but the closer you get, the less grinding you have to do.

 

Any of that usefull?

 

Geoff in the Great North Wet

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Guest MPerks89

Very useful. Thanks.

 

My forge is made from an old oxygen tank of some kind, with two venturi burners. It's lined with 1 inch of 2300-degree Kaowool and runs on a 20lb propane tank.

 

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By the way, that's not MY forge, it's a picture of the forge I bought. My forge doesn't get that hot.

post-1435-1111966046_thumb.jpg

Edited by MPerks89

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I use a 4lb sledge for most of my rough work, several peens to do other shaping techniques and if it just doesnt want to do what i need there is the 8lb sledge but i dont get that puppy out very often.

your anvil does sound like it poses a problem as well but if your temp isn't up then it wont matter what anvil your smackin steel on.

 

as far as running the forge your venturi burners will be a bit picky about how they are set up. I have a valve on mine to adjust the fuel rate but it's basically a way to cover my screw up in the build.

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I would guess that you are trying to forge at too low a temp. and that your forge needs a bit more insulation. Try Ron Reil's site, he makes the point (speaking about forced air burners) that it is possible to push too much cold air and fuel into the chamber of a forge and actually lower the temperature in there. One other thing to consider is that while the outside of the metal may look up to temperature that does not guarantee that the inside is. Try bring it up to a temperature lower than forging and leave it there five to ten minutes before bumping it up to forging temp. and soaking for another five minutes. When it is at the proper temperature even such a thick piece should move easily for you. I have a four pound club hammer (head looks like large diameter square rod) that I favor for breaking stock down rapidly. I can tip the head and hit the steel with the edge of the face, fullering it in effect, and than hit it flat on to smooth it out. I cannot swing that hammer too long before I start to loose control of the head, which is how I figured out the edge works as a fuller! I too have a soft anvil but, we all make do one way or another.

 

Hope this helps,

Bruce

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Guest MPerks89

If I add burner flares, will that make a difference?

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i'm also a pretty new guy

 

i bought a peddinghaus, 1000 gram, swedish-style blacksmith hammer from centaur forge

 

the pein end works very well for drawing out . it's a little more rounded than the regular 3lb pien hammer i've also tried. the regular hammer does little more than dent the metal, while the peddinghaus really moves it.

 

hope this helps

 

sp

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MPERKS: What size regulator do you have. If you have one of the regs. from a grill, it is too small. If you have a bigger reg.? Screw it all the way in and open up the gas, control it with the valve. A forge like the one in the pic. should work fine if you have enough pressure and don't shut th air off to it. After you have it roaring like a jet airplane, start cutting the gas and air back to suit you. You will find a place where your forge works the best. Good luck. :)

 

Chuck Bennett

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