Dry ice quenching?

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bushpilotmexico

Joined
Aug 23, 2004
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Hey guys,

This probably has been covered previously but darned if I could find a 'search for' link?

I've Googled to try and find the answer but no luck. I remember reading vaguely some where about the proper liquid to place the dry ice in to bring it down to temperature?

Other than just pancaking the knives between slabs. The problem is that I have a local source of dry ice it's usuually bits and pieces.

I guess with the proper liquid an el cheapo cooling chest would do the trick to act as an insulating medium?

Thanks
 
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If you use an el cheapo ice chest make sure it holds water before you start. Many foam chests are packed so loose they will leak all over the place. Second if you are using acetone foam chest is out. You need something that will hold up to it. I used kerosene. It stays liquid even at the super cold temps of dry ice. Also are you quenching or cryo tempering? I don't think I would quench in a pail of acetone or even kerosene.
 
Acetone gives you ~ -100 F and LN ~ -300 F.
OT - so I was watching a cooking show this weekend and the 'chef' puts the food on the plate then puts a few spoonfulls of LN onto the plate !!! He said it was to firm up the gel that was in the food...Now you know why I have no faith in most TV 'chefs' !!
 
That depends on what the person was cooking. Plain gelatin sheets are made from animal parts.
 
BE CAREFUL, Acetone and dry ice is VERY volatile! For the love of safety, do not quench hot steel into it unless you want an instant trip a couple counties over in little pieces.
 
Putting hot steel into any dry ice mixture is flat out crazy. Now if you want to cryo it after your hardening quench, that is a different story.

Dry Ice mixed with industrial alchohol or anti-freeze (yes, the kind you put in your radiator), will get you about -55 degrees F. I don't know what mixing dry ice and acetone gets down to. Acetone is not the safest stuff to use, so I wouldn't recommend it.

Always, always, always fill your container about half way with the liquid first, and then begin adding your dry ice. You're after about a 50/50 mix, give or take, depending on the quality of the dry ice. If the dry ice is contaminated with water, it'll start freezing up before it gets to -55 F. If it's pure dry ice, it'll be slushy, but not freezing up at -55 F. You're trying to get a slushy consistency. The neat thing is that eventually the dry ice will evaporate out of the liquid leaving you with your alcohol or anti-freeze for your next use. This process does draw moisture out of the air, into the liquid and eventually your liquid is contaminated to the point that you'll need new liquid.

This is a procedure that is commonly used to freeze bearings for installation into a hub.
 
A C Richards said:
Also are you quenching or cryo tempering? I don't think I would quench in a pail of acetone or even kerosene.
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Bad choice of words when I used quenching....I will be cryo tempering. I'll air cool between two aluminum plates then remove the wrap and cryo.

Thanks for all the info and links.
 
Been using dry ice and denatured alcohol for 10 years, not with hot blades though,
oven to cutting open packets in front of a blower 2, 4" by 18" 1/2" thick steel plates
until ambient or room temp then the dry ice.
Ken.
 
kc custom said:
Been using dry ice and denatured alcohol for 10 years, not with hot blades though,
oven to cutting open packets in front of a blower 2, 4" by 18" 1/2" thick steel plates
until ambient or room temp then the dry ice.
Ken.
Click to expand...



Hi Ken,

I agree completely with you I used the incorrect wording when my title said dry ice quenching.

What I don't understand is why the dry ice mixed into a medium be it alcohol, kerosene, acetone, antifreeze, etc. ends up with solutions at different ambient temperatures?

I'm not sure what the actual temperature of pure dry ice would be, probably some where around -75 degrees, but why if it was mixed with whatever would it drive the temperature of that particular liquid lower? -75 degrees should be -75 degrees?
 
bushpilotmexico, I don't think the temp is that radically different I've heard that
dry ice is at -109 to-110, mixed, boiling or evaporating or whatever you want to call
it the liquid should be fairly close to that temp. The fact that the blade is immersed in
the liquid is probably giving it a better contact with the steel?
Ken.
 
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