So I was trying to help a friend fix a doorknob with a lock that wasn't working a couple of weeks ago, and I couldn't figure it out, so I just took the whole thing in to a locksmith. This guy was scraggly as hell, but he definitely knew his work with the lock--was even missing a couple of pieces of finger. He ends up taking the whole knob apart, and then we finally located the problem, but as he was taking it apart, he encountered grease spread thinly over the internal part of the knob. Having learnt the wonders of grease and lube working on bike, I was wondering what kind of grease was good to use on a lock and knob, so I asked him, and he grumbled, as he wiped his fingers,
'Ah, I don't know. It's filthy stuff. I never use it. Gets all over your hands. GOOD locks don't need a lot of grease.'
I ended up paying him 12 dollars for a very easy fix that allowed me to avoid having to buy a replacement knob and lock for about 120 dollars; and in addition, the replacement knob would have taken a different key from the one that worked on all of the OTHER doors in my friend's house. (Also, taking it into him saved me a ton of money. If he had come to the house, he would have charged 40/50 dollars, minimum.) I thanked him profusely, admiring his arcane and useful knowledge, and he, in turn, thanked me for 'giving him the opportunity to work on a new lock.' Sounded a lot like people I know on this forum, relishing the opportunity to discover something new and add to the knowledge base.
I still marvel at his attitude towards grease, though in terms of locks, or rather the knob (not the keyhole), his reasoning made sense--the things just are NOT subjected to the same kinds of heavy stresses that bike parts are.
Cheers all, nice week-end.