[ Mike Blackwell wrote in 030205 MMDigest: ]

> I'm working on an old piano.  The action is pretty stiff.  According to
> Reblitz, the ideal answer is to take the pins out and ream the bushings.
>
> Not having the tools for this, I'm looking at his alternatives:
> alcohol/water mixture or center pin lubricant.  I've also heard several
> other chemical alternatives mentioned.
>
> Any comments on how well any of these chemical alternatives work?  Pros
> and cons?

Mike,  Many different things can cause an action to be "stiff", a
rather generic description.  While the action centers may be a little
tight you need to verify this before treatment.

The typical crude test is to remove various hammers with their flanges
from different sections of the action.  Hold them up and give them a
full swing.  The hammer should continue to swing freely four to seven
times if friction is correct. There should be no sideways movement,
only in a straight line.

If the hammer swings less than four times then there is reason to
suspect a friction problem.  This is especially true if the centers
have become contaminated with verdigris, a greenish colored corrosion
sometimes found on brass center pins.

If it swings excessively, (often 15+ swings in an old action), then
this is most certainly not your stiffness problem.  Tight action
centers usually cause sluggishness and poor repetition problems more
than stiffness since hammers return slowly.

Other common problems include tight key bushings, incorrect weight of
replacement hammers, or in most cases a poorly regulated action.  An
action in need of regulation often has the symptom of stiffness caused
by insufficient let-off, too much or too little key dip, improper blow
distance, or dampers lifting to early from the key.  Verify this first,
chances are very good that the center pins are plenty free and you may
cause some damage by unnecessarily lubricating them.

If you determine that the center pins are the problem I would suggest
using ProTek center pin lube available from Pianotek supply.  Apply
using a hypo-oiler with a fine needle.

Rob Goodale, RPT
Las Vegas, NV