Dry Ice & Acetone in PVC?

i4Marc

i4Marc

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Oct 19, 2011
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First of all, is a PVC tube a safe vessel for a dry ice & acetone mixture?

Next, when you quench in oil you should have at least a certain minimum volume of oil around the blade in which to quench. Is there a suggested amount of dry ice/acetone for cryo cooling a blade? That is, should there be at least so much distance on all sides of the blade? This will be for an AEB-L blade.
 
I would use metal, not plastic. I certainly would not put a solvent like acetone in PVC. Cold polymers and plastics are very brittle and break easily.

As long as the blades are fully submersed, the volume is not critical. I just use about a gallon of denatured alcohol and 5 pounds of dry ice in a long "fish cooking' pan. It even has a rack that holds the blades off the bottom and makes removal easy..
 
I use a stainless steel tray made to hold drywall mud, it was cheap and has held up very well. I line a styrofoam cooler with fiberglass insulation and it goes in the middle. This setup seems to hold temp nicely.
 
I have a large old stainless vacuum flask that seems to work well. It also makes sure that I put the knife in tip-first ;)
 
Which gets colder, dry ice and acetone or dry ice and kerosene?

* I read in another thread that denatured alcohol would be best and should take the temp down to -100˚. Would a sub-zero dip be recommended for carbon steels or is there no added benefit from it?
 
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The temperature achieved is really just down to the dry ice and the atmospheric pressure. At standard atmospheric pressure, it will be around -78 degC, or -109 degF. At altitude, slightly lower. If you use dry ice in a vacuum chamber, the temperature will go lower. Around -130 degC, or -200 degF, should be achievable with the sort of vacuum chamber some of the guys use for stabilizing wood.

The liquid, whatever is used, is effectively just there to evenly distribute the temperature. It's important that it stays liquid at the temperature involved, and a thinner (less viscous) liquid might allow faster convection and reach even temperature slightly faster. In reality, the time to reach even temperature is probably insignificant compared to the time you'll leave the blade in.

The best liquid is really the one you have available, as long as it stays liquid at the temperature.
 
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PVC reacts with acetone.. lasting a couple of seconds. Be carefull!!

as they told you, rather use a piece of structural steel or ir you are "fancy" you can use stainless

regards
 
Yeah, I'm staying away from plastic. I am sourcing a metal container right now.
 
I'd advise you to use metal like the guys said. But, I use PVC and haven't had any problems with it. I put the pipe in a bucket with sand around it to support it and insulate it. Acetone doesn't dissolve PVC very quickly at all when at below zero temps. So make sure you take the acetone out before it warms up.
 
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