kneading hammers

[David Nereson]

 < . . . . .

Yes.  It is quite possible to ruin hammers with Vise-Grips.

>Is it inherently more harmful than needling?

I wouldn't say so--but yes, if it's over done.  It reduces the amount of
needling
one might need to do to get similar results.  I feel the advantage is
speed
and ease--on the right hammers.

Be careful of mis-shaping the hammers.  Unless you really know what you
are doing, I would be very careful to avoid the strike point or the
area below  it.  In general, tread very carefully.  Just because a little
works, it doesn't mean a lot works better.

Off to work.  Good luck!

Barbara Richmond, RPT
near Peoria, IL                   > . . . . .
 It is also quite possible to ruin hammers with voicing needles, lacquer,
sandpaper, alcohol, hot irons, and steam.  Anything can be overdone to the
point of damage.
        --David Nereson, RPT