How to Break a Lock With Liquid Nitrogen or Canned Air

Locks are made of metal, and metal has one critical weakness; it's brittle when cold. So brittle in fact that it can be smashed like glass.

So, all you need to do to remove a lock is to super-cool it. But how? Well you have two options; liquid nitrogen and canned air. The former is more effective.

Liquid nitrogen can be bought at welding shops. It is very cheap too. With a boiling point of -321*F, liquid nitrogen is VERY cold. All you need to do to obtain some is to walk into a welding shop with a dewer flask such as a thermos. Ask them to fill it up and they will for a few bucks. IMPORTANT! DO NOT screw the cap on tightly! Pressure will build up and the flask will shatter explosively! Simply put the cap on loosely, and the liquid nitrogen should last for about 6 hours in a thermos, or a few days in a large dewer. 5 gallon dewers cost about $120, so it's not too bad.

Next chill the lock. This can be done by filling up a METAL can with liquid nitrogen and dunking the lock. It will boil vigorously, just add more lN2 as it evaporates. Eventually it will stop the vigorous boiling and the lock is sufficiently chilled.

Now take a 20 ounce hammer and hit the lock hard. It may take a few well placed blows but the lock will likely shatter like glass!

Option two is canned air; the stuff that you buy to clean computers. It contains high pressure 134a (1,1,1,2-Tetrafluoroethane) or the same stuff that's in your refrigerator/air conditioner. When you tip it over and squeeze the handle it releases liquid 134a at a temperature of -153.94*F. Nowhere near as cold as nitrogen, but it is still cold enough to embrittle cheaper locks. Get a big bottle, then simply chill the lock and smash with a heavy hammer.