Squeaky U-3/what kind of lube?

[PNHISTIC1@AOL.COM]

List,

I was tuning a 15-20 year old gray market U-3 today.  Not a bad piano at all, 
except for the occasional rattle-squeak-creak on a few select notes.  The 
owner of the piano is a PHD candidate in piano performance at North Texas 
State, so I determined to find the cause of the problem.  

After finishing the tuning, I removed the action, tightened every screw I 
could find, but the noises were still there.  I removed the whippen of the 
worst offender, did nothing special other than check for looseness, then 
removed and examined a jack spring.  Found nothing out of the ordinary, and 
put it back in, then replaced the whippen.  The noise was gone.  I 
deduced(eventually....:-)  that the jack spring was rubbing on the side of 
the jack near the nipple that holds it in place.  I took all of the noisy 
springs out and bent them ever-so-slightly so they wouldn't rub, and voila!!  
Noises were gone.

Does anybody regularly use ProTek or any other lubricant on these plastic 
jacks and springs?  I'd like to treat all of the jacks next time I go back, 
because it's a certainty that more will act up in the next 6 months.

Thanks,

Dave Stahl

PS  Made me feel good to hear a Bach Partita being played as I walked down 
her apartment stairs!  It's nice to tune for somebody who really appreciates 
it and benefits from it.  She even slipped me a tip!