How to Cryogenic Quench in the small shop?

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Eric Shaw

Joined
Feb 6, 2001
Messages
38
Is this something that we can do ourselves?
How complicated is it? Can we start a tutorial on it? Maybe Paul Bos could give some advice? Anyone with the know how feel free to jump in. Now that would be REALLY COOL!
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A real cut up one blade at a time!

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One Riot, One Ranger
www.shawcustomknives.com
 
Eric, Cryo treatment is easy enough to do at home. I started doing my own blades this year. I had paul Bos do them for years and have never had a problem, in fact my knives sold well because I had Paul Bos do all my heat-treat. I was forced to do my own after he quit treating high-carbon tool steels (thanks to EPA)which benefit also from the freeze treatment. He still does the stainless and air-hardening steels. I bought an Even-Heat oven with the rampmaster 2 control and 100 feet of stainless tool wrap. I also bought a 6 liter dewer off Ebay. It takes some practice and a rockwell tester to assure the final hardness is within the acceptable range. I use the community college tester. Its fun to test the annealed steel and then test it after hardening and freezing and tempering. Check with your local welding supply house for prices of the dewer and filling with liquid nitrogen. They will likely only fill a genuine dewer but they are not much different than a big thermos bottle. My 6 liter costs $22.00 to fill and will last for about 4-5 days if I keep the lid on. I am still learning the process and write down everything you guys say about times and temps. for different steels. Maybe Paul will chime in and give us some answers on the subject. Bruce B
 
Bruce, what do you use to put the blade in the liquid nitrogen and then take it out again?? Looks like tongs would snap off when you appied pressure.

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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!
http://www.nebsnow.com/L6steel
Buzzards gotta eat, same as worms!!!
 
Bruce,

Thanks so much for the info Bruce. It's a pleasure to read your posts because you're very knowledgeable and not afraid to share. This sounds VERY interesting to me, since all or most steels benefit from Cryo-quenching. I'll bet alot of other makers will possibly enjoy the knowledge of knowing that they can do it if they wish. Let's see if anyone else has anything to add.
Thanks again,
Eric
 
I used to be able to get my LN in a big Igloo water cooler. It worked fine other than making a little noise. Did it for a couple of years. THEN one day the local supplier got religion or something. He would only fill approved containers. DAMN...I hate the goverment and insurance companies...and soccer moms and...oh well you get the idea.
 
Michael, I just use a wire on each blade and slowly dip the blade in the liquid so it doesnt shock it too much. Paul Bos has a refrigeration unit of some sort to cool the blades slower. Ive never had any trouble shattering one but Ive never dropped one either. Bruce B
 
Eric, You are welcome. I am no expert on this subject but I have a few under my belt. Im still waiting for Paul bos to come in and straighten us out. Bruce B
 
Jim Hrisoulas mentions using acetone and dry ice in his book "The complete bladesmith".

Sounds like an easy and accesable approach, just mix dry ice and acetone the dip the blade. He does mention that if you just dump the ice in there it may explode, so you have to add acetone to the dry ice, and pour slowly.



[This message has been edited by TroyO (edited 03-24-2001).]
 
L6S,
would a metal colander/steamer/strainer work for dipping a blade in liquid nitrogen?


Culinary freak strikes again
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A genius learns more and more about less and less until he/she learns absolutly everything about nothing
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~Daniel a.k.a. DeLightsabor~
 
Stiletto,
Great link! Lots of info and a book to boot!Now we know of 2 ways to cryo-quench....Dry ice and kerosene for -120 F. and liquid nitrogen for the deep freeze -300 F. Where is the Bos? Don't tell me in Asbury Park either, that Bos spells it with 2 s's. (Boss)
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A real cut up one blade at a time
 
Devin and I routinely sub-zero quench the damascus that we use. Ive seen stainless go from 52 before quench to 57 after sub zero quench on the C scale. We normally quench for about an hour. We just use a wire as Bruce mentioned earlier and lower the blades into the liquid niotrogen. Our dewer is something like 5 gallons and last several months between refilling.

Terry Davis in his part of "How to make multi-blade folders" Speaks of a home built freezer that gets to -180 f. He doesnt mention how he did it but it would be an interesting project.

Arthur D. Washburn
ADW Custom Knives
www.adwcustomknives.com
 
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