Nother Heat Treat Question

L6steel

L6steel

Joined
Sep 23, 1999
Messages
5,855
I understand to cool air hardening steels you hold them in a stream of air. Whats best for the air supply? Will an air line from a compressor cool it too fast? Is a strong fan ok or would a small fan be better?? Thanks!!!

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Take care!! Michael
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Always think of your fellow knife makers as partners in the search for the perfect blade, not as people trying to compete with you and your work!

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Most HT experts say to quench air-hardening steel in *still* air, which is what I do. I have had no problems.

Don Cowles
 
Press quenching???

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Take care!! Michael
jesus.jpg


Always think of your fellow knife makers as partners in the search for the perfect blade, not as people trying to compete with you and your work!

My Web Site
Buzzards gotta eat, same as worms!!!
 
Press quenching:

Soon as your 440c or V blade comes out of the oven (in foil of course") set it down onto a solid block of aluminum with two pieces of stock laid on the sides of the block the same thickness of the blade. Quickly lay your blade into the middle of the two pieces of stock upon the block of aluminum. Then lay another block of aluminum on top of the whole thing like a sandwich and stand on it for 30 seconds. The two pieces on the side keep you from rolling the blade from side to side as you stand on it. After 30 seconds you can unwrap the blade with leather gloves..... 60 seconds later you can handle it with your bare hands. The aluminum you sandwiched it with absorbed all the heat from the stainless steel. Hence...... press quenching.

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www.burnknives.com
 
Burn, Do you put brown paper inside the foil to burn off oxygen while cooking? Does it matter how thick the aluminum plates are? So you leave the blade in the foil and press? How do you keep the pouches from plumping up when heating? Bruce B
 
Michael, I think rapid cooling of steel is important for hardening. The problem is avoiding warping with uneven cooling. I use a small 12" square box fan with blade edge straight into the breeze, a gale force isn't necessary. Some trial and error may be needed to fine tune your process, I have a new oven and needed to change my temp. a little. Thankfully, the steels are a little forgiving. The press quench is interesting, new to me also.

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ColoradoBoy
 
I've never yet used any paper inside with the blade personally but heard of others that do. I wrap mine up in foil so well that when I unwrap them the blades look the same color when they went in... sometimes maybe the tips or tangs turn light blue, but rarely. The paper will keep that from ever happening. I have an aluminim block I picked up at a scrap yard for $5 that is one inch thick and 3" wide and 6" long. I use it as my bottom and my top is only 1/4" thick...... I've also used brass on the top 1/4" and find it works just as good. I grind my blades with a 3/32" edge left only and have never had a warped one yet with this method because the blade can't move while the heat is being sucked out sandwiched like this. Leave the blade in the foil...... as soon as you pull it from your oven with your tongs place it right onto the block immediately. I have my blocks right underneath my oven. Count to 30 slowly and then step off them. I normally pick the blade up still in the foil with my tongs and set it on my bench while I'm placing another blade into the oven. By the time I reset everything I can unwrap the warm blade from the foil with my hands. Jim Ciska taught me this, its how he does most of his.

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www.burnknives.com
 
Wow, thanks for all the helpful info guys!!!! Would a 2 1/2" thick piece of d2 work for the bottom plate??

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Take care!! Michael
jesus.jpg


Always think of your fellow knife makers as partners in the search for the perfect blade, not as people trying to compete with you and your work!

My Web Site
Buzzards gotta eat, same as worms!!!
 
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