Hello all. I've stored a bike outside for a while, and haven't opened the lock in a while. Today I went outside to work on the bike, and I couldn't open the U-lock (Masterlock, standard U-lock). I have the correct key, and I can put the key into the lock and even turn the key, but the lock will not open once I turn the key. Does anybody have any tips on what to do?

Soak it in PB Blaster overnite - then try again.

if you dont have time to wait for the blaster to do its job, turn the key to the unlock position and give it a few gentle taps with a light hammer or mallet. it should knock some of the corrosion loose & release the spring.