Shrink Fits/Freezing 1

[swall]

I've heard of people using a CO2 fire extinguisher to chill parts for shrink fits. My question, is does anyone make a CO2 system specifically designed for this?

 

[unclesyd]

Try a search for pipe freezing systems. Look for the type for plumbers.

 

[BillPSU]

Typically people use dry ice and alcohol to shrink parts.

 

[bluesman0007]

We always have a tank of liquid nitrogen around works fast.

 

[swall]

Oops, I should have mentioned that I don't have dry ice available in my area. I may be able to get LN2 from my welding supplier, though.

 

[mechantaeus]

I have always used liquid nitrogen for such applications, but the feedback is dry ice works better.

-mech

Work Hard and Work Smart

 

[jarvis]

Why can't you just get co2 from the oxy supply? Also I believe I saw someplace that you can buy a little thing to hook up to your co2 tank and make dry ice.

Ben Englund

 

[swall]

Yes, I have been looking for a device to hook up to a CO2 tank. Haven't found one yet. That's why I brought up the fire extinguisher comment in my original post. Might work in a similar manner.

 

[unclesyd]

Here is good palce to start.

http://www.cob-industries.com/qwikfreezer.htm

 

[swall]

Thanks Unclesyd. I had started looking for the pipe freezers per your earlier post, but all I came across were the LN2 type. This little CO2 oufit sounds like just the ticket, if not too expensive.

 

[unclesyd]

Watch your CO2 tank as it has to deliver liquid not gas as in welding gases.

 

[jarvis]

If you want a co2 tank to dispense liquid, get one with a siphon tube inside. We have one for filling painball gun tanks with. We get it from a welders supply.

Ben Englund

 

[LesterPester]

Yeh, while you guys are on the subject of dry ice the next time any of you are in a hail storm do this: buy some dry ice, cover the infected area of the car with the ice, then cover it with a insulating blanket, then wait for a sound that sounds like pop-corn poping. When you don't hear the sound anymore remove the balnket and let the dry ice disperse. You probably only have to rub out your paint job. I have used this sysytem several times in the past and it works well. ON the pipe I have even used freon to shrink the pipe.

 

[swall]

Very interesting.My Mustang received a hail demolition job several years ago and most of it was fixed the old fashioned way--replacing the sheet metal.

 

[surfdog]

We put our parts in the freezer and the mating part in an oven.....works great.

 

[swall]

Yes, that's what I've been doing, surfdog. And, when I take the parts out of the freezer, I put them into an acetone soaked shop rag for about 5 minutes for more cooling. But, I would like to get a chilling system faster than overnight in the freezer. I have literature and pricing coming from the liquid CO2 chiller people.

 

[bugnut]

Know this sounds to ez but I worked in a model shop which required something similiar. Could not find a source for dry ice till I called the local ice cream shop. Not terribly expensive and they always had a ready supply.

 

[Capntom]

Try mcmastercarr.com. They carry the pipe freezing kits. As for the "freezer" method. Remember it is the change in temperature that causes the shrinkage/expansion. Freezers are only 32° F. That is only a change of 40°.

 

[swall]

Yes, I did manage to find a liquid CO2 freerzing system. But, the price was not to my liking. Will pursue the ice cream shop source or possibility the Swann's ice cream delivery people.

 

[golfer94]

We use dry ice for sweat fits on paper converting roll journal replacements. I purchased a small dry ice maker that uses liquid CO2 from a "dip tube" cylinder. You can get this type cylinder from your local welding gas supplier. The machine is an Insta-Ice mdl. 485 mfg. by PolyFoam Packers div. Tuscarora in Wheeling IL. 60090. It makes approx 4-5 standard house brick size blocks of dry ice per dip tube.

A hint, to get full coverage around your parts place them in a styrofoam coller and submerge them and the dry ice in kerosene.