LN2 and sleeves

[WW2N]

Went to my welding shop for dry ice to use on sleeves, he says use LN2--- anyone tried this.

 

[TheOldHokie]

Went to my welding shop for dry ice to use on sleeves, he says use LN2--- anyone tried this.

I have never used it but it will work. Whats their price?

TOH

 

[Jeff Hamilton]

I've heard of using liquid nitrogen to cryro treat metals, don't know why it wouldn't work. SO, I googled it. Up pops an ad "Vaxxen Labs Chilling Spray" .83 pounds, 30 bucks - plus lots of other options. On that jungle website.

 

[Jim.ME]

In industrial settings liquid nitrogen is commonly used to shrink things.

 

[TheOldHokie]

 

[WW2N]

I have never used it but it will work. Whats their price?

TOH

We have a fleet of welding units mud trucks and stem pipe rigs. We Do 6 figures with this shop, so he said its free

 

[40Mule]

I would like to caution anyone thinking of using this that Liquid Nitrogen is dangerous. We used this at engine plant to shrink liners for a robot to insert in straight six engines. Use safety glasses at a minimum and thick, thick, thick gloves. We had extensive safety training. The liners were run thru a tank in a checkerboard pattern with a 5 inch square base with a hockey puck shape on top that the liner sat on. I think robot put three liners on puck and they advanced as robot on other end pulled three and dropped in bores. If one did not drop, you still had to knock the liner in once in a while with a large plastic hammer.
This is what dermatologist uses to freeze that bump off your arm that you wondered about. Be Careful, old methods work. If you screw it up, you may be sorry you tried. I know I screwed up a lot. Please do not stare in a bucket of this without safety glasses, parts are incredibly cold that you cannot feel. Our gloves were super thick if we had to work in that tank, and the cold still came through. This is just my opinion but be careful. Keep this away from kids and practical jokers.

 

[WW2N]

Thanks for the heads up.

 

[Dave G9N]

The video shows a lot of LN2 being used in an AREA OPEN TO THE OUTDOORS by people who presumably knew the danger of suffocation and how to avoid it. If that was indoors without some serious ventilation everyone could easily have suffocated. You will pass out in 20 seconds breathing pure nitrogen because it flushes the oxygen out of your blood. It was not a good day when we learned about that. I worked with the survivor.

The temperature of LN2 is about -320F. A 3 inch steel cylinder at 70F will shrink 0.007" by the time it reaches -320. The problem is keeping it cold, so it takes a lot of gas flowing to keep the part cold while it is inserted.

It would be safer and might be easier for most of us to make a Styrofoam plug and put some dry ice in the cylinder. It will only shrink about 0.003" but it is easier to handle than LN2. Dry ice snow should be better than chunks for heat transfer since it should conform to the shape.

 

[Non-farmer]

I simply put my sleeves in my freezer overnight. They dropped right in the next day. I had to gently tap 2 of them with a piece of wood.

Liquid nitrogen strikes me as serious overkill and, as has been pointed out, can be very dangerous.

 

[TheOldHokie]

I simply put my sleeves in my freezer overnight. They dropped right in the next day. I had to gently tap 2 of them with a piece of wood.

Liquid nitrogen strikes me as serious overkill and, as has been pointed out, can be very dangerous.

Overkill maybe but no more dangerous thsn a chain saw or handgun. Probably less dangerous than the gun.

We were using liquid nitrogen in 8th grade chemistry class circa 1965. Did you know you can quickly dip a bare hand in and pull it back out without injury? Its called the Leidenfrost Effect. I dont reccomend you try that but its a fact.

Dan

 

[Non-farmer]

I have yet to meet anyone who replaces sleeves using a chainsaw or handgun.

 

[TheOldHokie]

I have yet to meet anyone who replaces sleeves using a chainsaw or handgun.

Nice deflection.

TOH

 

[Non-farmer]

Why the **** should someone use a potentially high-risk method to do something when there's a no risk option that anyone can easily use? That question is rhetorical.

 

[Mad Farmer]

I worked a lot with liquid N2 in scientific settings. You need to be careful or you can injure/hurt yourself.

We had a big tank and we would collect what we needed in big Dewar flasks/thermoses. Long sleeve clothes w/underlayer, boots, gloves and goggles.