hammer filing

[Carl Meyer]

I teach a class entitled "Make your own tools"  I did that at the 2000 Cal
state convention and at several chapters.
The hammer sanding procedure may be interesting to the list.

I just brought an action in that needs reconditioning if that is an
acceptable term.  It's a 1926 Cable Nelson, not badly worn but looks like it
hasn't been cleaned, regulated or tuned since I don't know when.

Now for the hammers, I first propped up the hammer shanks by laying a 1 inch
PVC pipe 5 ft long over the whippens which holds the shanks level about
where they would be at the strike point.  I then took a drill press vice
that I can slide along the bench and clamped a wire in it and bent it so
that it points down at the center groove of the hammer.  That groove is the
reference point for the location of the center string of the piano which is
still at the customers house.  Now I loosen the hammer flange screw and
position the hammer so that the center of the hammer striking surface is
under the pointer.  I have now adjusted the hammer registration before
sanding when I will lose my reference after the grooves are gone.

Now I'm ready to sand.  I have two aluminum angle extrusions with back rail
cloth and emery cloth and clamp the hammer shanks.  The extrusions minimizes
the flexing of the hammer shanks.

My sander consists of an electric carving knife with special blades bent to
the shape of a Y.  Then a loop of 1/2 inch wide 4 inch long 50 grit cloth
backed sanding strips are double back taped to form a shoeshine strip.
The coarse sandpaper clogs quickly so that you have to use a rotary and
horizontal motion to keep the waste felt cleared.  I showed this at several
exhibit halls at state and natl. conventions.  I think I sold about 40 kits.

I can do mildly grooved hammers in about 20 minutes or so.  Some felt
doesn't sand well due to the way it is layered but most sand very quickly.
Gang filing or touch up may be necessary to square them up, but the rough
work goes fast.  Nick Gravagne has demonstrated it in several of his
classes.  He's sold more of them for me than I have.  I'm not actively
exhibiting then any more, but I still have a few and can make more.

E-mail me privately for more info at cmpiano@home.com

Carl Meyer


----- Original Message -----
From: "Robert A. Anderson" <fandango@dakotacom.net>
To: "Pianotech Digest" <pianotech@ptg.org>
Sent: Monday, May 28, 2001 11:44 AM
Subject: hammer filing


> I used to use the Dremel with the guide back in the "old days." It was
> certainly fast, and the typical piano I was working on was an old upt.
> with mostly shot hammers. As I began to get more experienced, I started
> working on better quality hammers. I came to the conclusion that I
> didn't have enough control with the Dremel, so I started filing by hand
> exclusively. Then someone showed me how to use the Dremel freehand. I
> discovered that I could do that with practice. It is pretty easy for me
> to make controlled freehand passes all the way around the hammer. The
> limitation of this method is that it takes felt off evenly, whereas I
> may want to remove a lot of felt from the shoulders to restore the shape
> of a badly flattened hammer. I don't find that the Dremel saves me any
> time in that situation. I can rough-file the shoulders with a coarse
> sandpaper file faster than I can with a Dremel. After restoring a more
> or less normal shape to the hammer, I can follow up with the Dremel
> freehand. Then I go back for final touch up with a sandpaper strip. I
> guess the bottom line is that it may be better to consider using a
> combination of tools on any particular job than locking oneself into the
> use of any one tool.
>
> Even if you use the Dremel, I think it's a good idea to develop a
> technique of filing by hand. Not all hammers want to be filed the same
> way. I get better tactile feedback when I file by hand and I consider
> that my primary technique, even though I use the Dremel in certain
> situations.
>
> Bob Anderson
> Tucson, AZ
>