[pianotech] bearing point problem

[Jonathan Golding]

Greetings list,

I recently tuned an old heintzman upright which game me lots of
problems and so I'm seeking some advice for future tunings.

I've tuned it in the past with considerably less headache, but this
time it had been put in storage for a while and then moved back to its
home. There was a lot of rust and grime across the bearing point and
on the strings themselves which wasn't there before. I put protec on
the strings (where they touch the bearing point) but to no avail. I
guess it wasn't enough to cut through all the crud which was
preventing them from moving properly. Several years ago, I used liquid
wrench to do this kind of thing which I think worked better at cutting
through both the rust and also lubricating, but I didn't like that it
would leave a black streak across the agraffe or bearing point area.

Any thoughts on something that I could use which would be safe, clean
and effective at cutting through rust while lubricating all at the
same time?

Or better yet, any thoughts on how do deal with this situation-
there's nothing worse than a string that doesn't move until a quarter
turn of the tuning pin only to move a quarter tone sharp.

Thanks and happy holidays,
Jon