I recently picked an old lock that has been in the Alaskan weather for at least 8 years. I had to WD40 it and hit it with a hammer to get the core to turn. When I picked it I almost broke my tension wrench and this one was home made and a lot tougher than most. In the end I had to insert a bump key to turn it open. I haven't been able to open it since. I know I have it picked its just jammed up. Any advice? It looks looks like a Master lock No. 3 knock off with 4 pins. Master lock M1 key fits. Save it or cut it open?
I'm not an expert but I have been playing with this a bit lately. There are some options, on locks that have rust you can use electrolysis to remove the rust. Its fun, but don't breathe in over it.
The other thing is to use Isopropyl alcohol (99%, not sold in CVS, look of it in electronics stores) in an ultrasonic cleaner.
I've had some success with it. I'll be happy to dig up pictures and post them in a bit.
Here is a set of photos of the setup and the locks initially and after(start at the bottom to see original condition and work up). http://imgur.com/a/QOLYt
