fine grit hammer filing

[Dave Nereson]

----- Original Message ----- 
From: "Don Mannino" <donmannino@comcast.net>
To: "Pianotech" <pianotech@ptg.org>
Sent: Tuesday, November 09, 2004 11:39 PM
Subject: Re: voicing/juicing ronsen hammers


> . . . . . They still needed a little more, so I filed them with 1,000 grit
> sandpaper . . . . . <

    Isn't 1000 grit about as abrasive as, say, newsprint?  I'll admit that
most of the hammers I've filed are on old pianos whose hammers have never
been filed since they were built, and the string cuts are an eighth of an
inch deep or more.  Sometimes I'll re-file a job someone else botched.  I
seldom have a chance to do voicing on really nice grands.  But even there,
I've never used finer than 120 grit.  Using finer seems like going past the
point of diminishing returns.  Does going up past 320 or so really make that
much difference?
    I would think that under a microscope, the surface of piano hammers
would look something like an overgrown back yard or maybe an Afro hairdo.
Sanding something this fuzzy and fibrous with 1000 grit seems to me like
"brushing" your cat with paper to smooth out its fur.
    What's the finest grit you ever use, and why?
    --David Nereson, RPT