How to freeze bushing ?

[jimpad]

I'm in the process of changing bucket bushings and I want to freeze bushings to ease reassembly. Local dry ice guy is out till thursday. Don't have CO2 fire extinguisher. I have nitrogen and oxygen tanks and road salt. Can I somehow use the gasses to freeze the bushings? If I use ice and water to freeze them should i be concerned about the salt causing corrosion between the bushing and bore? A better way?

 

[digger doug]

Your nitrogen tank a liquid one ?
I've seen ice and alcohol, but IIRC it doesn't get cold enough.

 

[jimpad]

No, I think it's gas... looks like small welding tank.

Does the alcohol melt the ice?

 

[funwithfuel]

I think it's best to wait for the dry ice. You'll be glad you did.

 

[Tinkerer]

Do a search for dry ice.
Grocery stores, Meijer's and Costco sell it.

 

[Tags]

See if your local welding supply has liquid nitrogen. Works the best. Some places will loan you a suitable container to transport it in.

 

[funwithfuel]

Don't try that crap about "put it in the freezer overnight " it doesn't get cold enough and the .0005" you gain from that insufficient heat loss is gone 3 seconds after pulling it out of the freezer. Dry ice and liquid N draw so much more heat out of the bushing. It provides you with time to work. Good luck

 

[JEVANS]

I have used Liquid propane. But obviously you have to do it away from any ignition sources and in a well ventilated area ie: outside. Its a little hillbilly and I wouldn’t make it a habit, but it does work decent.

 

[jimpad]

Hopefully airgas has liquid nitrogen on monday. I'm usually a bit of a risk taker but the propane scares me.

 

[funwithfuel]

What I like to do, especially with tight interference fit parts. I'll throw the bushing/bearing into dry ice and listen to it scream. (Always get a kick outta that) When the screaming stops, I let it just sit in thete shedding heat. At the same, I'll run the torpedo heater at the work piece to bring the whole piece up a couple hundred degrees. .003" shrinkage with .005" expansion gives you more time and space to make the fit. Good luck

 

[IceHole]

Dry ice doesn't do much. Better than nothing though.

It's only -40*. From room temp, that's maybe a 120* temp drop which would shrink less than 0.001"

Nitrogen is around -300 to compare. Around 0.002-0.003" shrink

 

[IceHole]

Hopefully airgas has liquid nitrogen on monday. I'm usually a bit of a risk taker but the propane scares me.

Propane is about same temp as dry ice, not that cold.

 

[Tinkerer]

From Wikipedia ;
Dry ice sublimes at 194.7 K (−78.5 °C; −109.2 °F) at Earth atmospheric pressure. This extreme cold makes the solid dangerous to handle without protection from frostbite injury. While generally not very toxic, the outgassing from it can cause hypercapnia (abnormally elevated carbon dioxide levels in the blood) due to buildup in confined locations.

 

[Vetech63]

I admire the guys that can swing a 20 lb sledge and drive those bushings in without freezing.

 

[funwithfuel]

Then spend the next hour grinding out the bore cuz it's peened over and the pin won't fit. Too old and too little to be swinging a hammer like John Henry.

 

[LN Pipeline]

When I need to install bushings, I get liquid nitrogen from the local guy that fills semen tanks. I just have him dump enough to submerge the bushing into a small styrofoam cooler.

 

[Truck Shop]

I admire the guys that can swing a 20 lb sledge and drive those bushings in without freezing.

Pew---you left the door open with that one.

 

[IceHole]

From Wikipedia ;
Dry ice sublimes at 194.7 K (−78.5 °C; −109.2 °F) at Earth atmospheric pressure. This extreme cold makes the solid dangerous to handle without protection from frostbite injury. While generally not very toxic, the outgassing from it can cause hypercapnia (abnormally elevated carbon dioxide levels in the blood) due to buildup in confined locations.

Guess I learned something, was always told -40*

That's around 0.001" shrink.

 

[Tony Wells]

I've used dry ice and acetone. Not as cold as LN, but better than most. And you can make your own dry ice. I have an attachment for a C02 bottle (must have dip tube) that makes dry ice "snow". The acetone also helps with heat transfer by contact with the warm object and dry ice. Bucket bushings would normally require quite a but of shrink. LN would be the best shot. Get some in a Dewar. Use in ventilated area. And don't strike the bushing while cold.

Handy list:

List of cooling baths - Wikipedia

en.wikipedia.org

 

[jimpad]

Couldn't wait, this worked well...