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Seized rusty parts by freezing

BMG50

Well-Known Member
Premium Member
Been trying to remove a rusted up cast iron plug. Been using plus gas by heating and soaking but using a hot air gun than a blow lamp. Have tried acetone as a soaking method to penetrate further. But rather than heat which can be destructive I wondered if anyone has freezed a plug nut or bolt just to break the rust seal so the penetrating oil can penetrate further. If I surrounded a base plug seized on a mills with plasticine and froze the the centre of the base plug with the plasticine protecting to avoid contact with the body using pipe freezer from a can that plumbers use to freeze pipes. In theory the base should contract and shrink, the opposite of heating the body which would expand. Do you think freezing would work to free up a rusted part to break the rust seal? If this did work that's if anyone has tried it then it would be a plus than using heat that could damage paint work and markings etc. What do you think.
 
It's depending on how cold you'll define "freezing" :) If you put it in the freezer I think nothing will happen. Cooling it down from +20°C to -20°C is 40°C difference. It's like heating it up from 20°C to 60°C which won't have any effect.

If you have access to liquid nitrogen it may be different but keep in mind, that steel especially cast iron can break much easier at very cold temperatures.

I wonder if anyone have tried an ultrasonic bath for the same purpose?
 
I am in the field of Aviation and use Kroil. The absolute best stuff on the market. Acetone flashes off and has no lubrication properties. I have had this can of Kroil for a decade, even ran over it with my Shorland once, it survived. I just used it on a 57mm Recoiless shell fuze where the aluminum fuze and steel threads had a bad case of dissimilar metal corrosion. It took one week of soaking in Kroil and tapping it with a rubber mallet ( Kroil and vibration will free anything and everything). PB Blaster is a second place favorite.Heating and cooling also works, soaking the piece in the hot sun and immersion in Kroil also works wonders, heat gun or hair dryer also. Trick is minuscule expansion, contraction, over and over. Time and patience. Pictures?
 

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Here's an interesting snippet I just found while goolging for Kroil in Australia:

http://www.vwwatercooled.com.au/forums/f77/best-lube-penetration-34427.html

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Some of you might appreciate this. Machinist's Workshop magazine tested penetrants for break out torque on rusted nuts.

They are below, as forwarded by an ex-student and professional machinist, Bud Baker.

They arranged a subjective test of all the popular penetrants with the control being the torque required to remove the nut from a "scientifically rusted" environment.

*Penetrating oil ..... Average load*
None ...................... 516 pounds
WD-40 ................... 238 pounds
PB Blaster ............... 214 pounds
Liquid Wrench ......... 127 pounds
Kano Kroil .............. 106 pounds
ATF-Acetone mix.......53 pounds

The ATF-Acetone mix was a "home brew" mix of 50 - 50 automatic transmission fluid and acetone. Note the "home brew" was better than any commercial product in this one particular test. Our local machinist group mixed up a batch and we all now use it with equally good results. Note also that "Liquid Wrench" is about as good as "Kroil" for about 20% of the price.

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The acetone mix may be worth a go!

Cheers
D
 
I would be very carefull about freezing as any moister present,and condensation will form before it freezes,will expand and possibly cause damage....a dumb question,have you tried tightening it first as this often breaks the 'seal' on siezed parts?

Tony
 
I was wondering if a ultrasonic bath would get into the threads.
I found an ultrasonic jewelry cleaner at a thrift store and tried it on a badly rusted MP40 mag loader with no success. It was in either WD-40 or liquid wrench and I believe I left it on for a full day, dawn to dark. I don't like leaving things running overnight. I believe I tried again the next day but don't remember for certain.
Bill
 
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