Instructions for "Deep Freezer" Quecher..??

Possum

Possum

Joined
Jan 27, 2000
Messages
266
Howdy There YAll.....!
Need a little help here. Got a problem on how to go about building a "deep Freezer" for queching blades in. Can't afford the liquid nitrogin stuff, so wondering if it was possible to build a freezer. any help would be surely appreciated.

Later "Possum":cool:
 
Not an expert by any means, but I have been hearing about the dry ice alcohol method. It gets down to something like -135f. I would think that you could use one of those Rubbermade sealable containers with about 5 pounds of dry ice. Let it sit for something like 7-8 hours. Some say its just as good as deep cryo. Some say that it is only about 75% as effective. Some say it does nothing. I don't now, but what the heck its worth a try.
 
I think it's more like 90 below with dry ice.
I nitro my blades -300+ below
you need to stop the molecules from moving and it still won't happen Evan
 at -305  but it's the closest you can get.
if you get a nitrogen Dewar you can get nitrogen for around  a buck a pound,
be very careful it can do more than frost bite you.
 
What is the best way to handle small quantities of liquid nitrogen? We use it at work, but just take it from the bulk tank and put it in open containers. I know if you put it in a plastic coke bottle and screw the lid down tight then hide it behind someone the bottle will explode and scare the heck out of them. Can you carry it in an unvented thermos and what about storage??? or do you just get enough to do your job then let it evaporate??
 
I quenched some small O1 blades in dry ice and acetone. I bought about 2lb of dry ice, put the blades in a styrofoam cooler, covered them with thedry ice then acetone, threw towels and blankets over the whole thing for the rest of the afternoon.

The acetone ate holes in the side of the styrofoam container, will need to use something else next time.

BUT, those blades have held up to wood carving better than anything else the customer has used. I'm going to work on refining this some more too, and would be very interested in hearing what other's experiences are. So far I'm a believer.

Not that I wouldn't love to use nitrogen! You can farm this out to places like Texas Knifemaker's Supply.

Dave
 
Possum,
If all else fails, you can send your blades up to me and I can leave em outside overnight. It was -22F last night. :D
 
I highly recommend International Cryogenics line of liquid nitrogen storage dewars. They are reasonably priced, and come in a variety of sizes. I have been using their 20 liter model for about 2 years now with no problems. I get my liquid nitrogen at Wright Bros. welding supply for $2 a liter. As long as I don't do too many big blades, a full container lasts almost 3 months. From all the testing I've done I have yet to see anything but positive results from a deep cryo quench. Just remember to temper after the cryo cycle for best results.
 
sattley
in a coke bottle?
your scaring the hell out of me..
at -305 deg below zero, I hope it doesn't get on someone.
  guys it's not acid but it can be dangerous just he same.

:eek:
 
I have been wondering about this for a while. The place that I work uses nitogen for doing interference fits on shafts, there is a lot kicking around but I had never worked out a way to get it home.

If you need to get the metal that cold, why do some people say that they have had better results from blades cycled through the kitchen freezer?

Acetone and styrafoam cup??!! LOL :D that is funny. I would go for some sort of coke bottle, they are polyester and pretty impervious to solvents, well, acetone anyway. Could insulate it with polystyrene peanuts, blister wrap, find a BIG bit of foam from packing TVs or similar.

And as a side note. Who here has tried sticking their hand in liquid nitrogen? :D Kinda cool, like you hand is in front of the airconditioning!! Not a problem as long as you don't leave it there too long. Sounds nuts but it isn't....much. The heat from your hand causes a gas layer to form that insulates you from the liquid. Won't last long, maybe not as much as a second, I didn't wait to find out. Was told that it there was real danger if what you were wearing got soaked and held the stuff against you. This was all at a university physics open day. Only young and dumb once!

Good luch all.
 
Well I don't like to encourge bad habits but I hate scare tactics too. The sutff is dangerous. So is a forge. It is not acid as already stated. When I used it the first time I found a supplier who didn't care what I got it in. I put it in an Igloo water cooler. The big yellow ones you see in the backs of trucks. It cracked and groaned and made hells of noise but held together. Over the years I have splashed myself by accident many times. I have never had the dreaded freeze burns. My point is to use a little caution but don't be frightened off from anything because some safety expert, government official or soccer mom says it's dangerous. Knifemakers are a different breed. I doubt there will be many more generations of us because of roadblocks from big brother but until then, let's try to maintain out independance.

I can remember when you could buy explosives at well stocked hardware stores. I remember buying guns through the mail. I remember voting without showing ID and smoking on airlines. Don't secumb to the hysteria BS spewed by the safety experts or we won't be able to buy the stuff anymore (like Freon).

end of soapbox rant! :mad:
 
Guys,

You can buy a GOOD, SAFE dewar big enough for blades for under $200. Do a search or maybe check Ebay. They charge me $8 to fill mine sometimes if they're busy, I DO IT for FREE ;) It often lasts for 20+ blades and leaves some left over to freeze bananas for the kids, that's always a crowd pleaser!!! At this price it works out to be CHEAP!!!! No fuss, no muss, no spills lowest temp for the buck !!

Neil
 
 let me poke at this one more time.
I'm not saying it dangerous to you that know what your doing.
to thoughs that don't..
you can have kids around, people that goof off,
others that play tricks, we are under fire by anti-knife nuts
that want no more than find a reason to put us
out of business this would just make for another nail
in the coffin if someone gets hurt and the lawyers
get into it and relate it to knife making.
you can't tell me I'm wrong here.
I'd be the first to go back to yester-when but
as they say you can't go back.
 
I was curious about the thermos because Bob Terzoula mentioned using them in his book.
Didn't mean to start a war over the safety thing. Let me clarify... while wearing the appropriate personal protective equipment, (cryo gloves, face shield, and apron) we have been known to pour the remaining liquid nitro in a plastic coke bottle. then with the lid removed, place the bottle in a warm place a safe distance from someone who is not paying attention, screw the lid on, and get away. The bottle ruptures with a spetacular pop and a big vaporous cloud. the reason I ask about transporting in thermoses, is I wouldnt want a thermous to come apart in my car with a "spetacular pop and a big vaporous cloud". Hope that clears everything up.
Thank You
Leonard
 
a cloud in the car would make for interesting driving..
I think I'd go with the trunk with the cap just a tad loose first.
no war here, just someone could take the info wrong and play some
 bad games with it. I had a guy one time in the machine shop I was
working in light off some fire crackers behind me and it was
pretty funny back then and all was well, I didn't get wrapped up
in the miller I was working with at the time.., I also in the same shop got my hand
slammed in a 50 ton flywheel type press. I was a very lucky dud
It just broke one of my fingers and took one finger nail completely off.
but if it were the case where someone caused this to happen goofing off
someone would have been canned. 
I guess getting older is making me think a head more.
 
I dunno Graymaker, I expect I'm older than you and the older I get the less tolerant I become of people and groups that want to tell me how to do something for my own safety. This wasn't directed at you.
 
I know what you mean.
the government feels the need to protect us from our selves.
but who protects us from them?
I feel have the right to do just what I please
as long as it does not effect others but one
needs to have in site and foresight for this.:(
 
Liquid nitrogen boils at room temperature, which means that any container that is sealed will build up an extreme amount of pressure very quickly. If for example you tried to unscrew the cap on the coke bottle then you would be rewarded with a blast of super cool liquid + gas to the face, hands and chest - not fun. Any container that you are going to close and use to store liquid Nitrogen should have a pressure release value which you always open before you open the container.

If you are transporting it in an ordinary thermos, then don't seal the top tight, allow the vapor to excape. As well take out any plastic or rubber seal, if possible as they get very brittle and will fracture very easily. As well if the cap is made out of parts glued together they will most likely come apart as very few glues will remain stable at liquid nitrogen temperatures. The thermos will also become very cold and difficult to handle rather quickly, especially the metal ones and of course become very fragile.

As far as sticking your hand in it, yes this is possible as are a few other things like pouring it over your hand. However while they are possible to do without harm, they can also very easily cause great harm. Know what you are doing and be willing to take the consequences if you make a slight mistake.

-Cliff
 
Lots of good information. I had not thought through all the problems of transporting liquid nitrogen...industry and research labs make it look so easy :)

Cliff, don't get me wrong, that wasn't the sort of thing that I would usually do in a million years. It was all part of a chat/talk given by a physics prof about the properties of cryogenic fluid. Additional trivia was that you could sweep your tiled floor with the stuff, as some janitors at the uni had discovered!:eek:
 
Something someone mentioned here before, be careful not to breathe any of the aforementioned vaporous clouds. It can shut down your lungs in an instant, and a respirator is not proof against it.
Besides that, are dewars ever available to rent?
 
lOCAL WELDING SUPPLY RENTS DEWARS FOR 5.00/DAY AND LIQUID NITRO IS 1.50/LITER. IT COULD NOT BE EASIER. FOR 20.00 YOU CAN DO A BATCH OF BLADES WITH VERY LITTLE HASSLE.
 
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