[pianotech] Cosmetic aspects of filed hammers

[Jack Houweling]

Hi David,

Yes I do use the Dragon skin paddle below the staple it is very rough and
with good control you clean and 

file at the same time. This is a before and after hammer, I first used the
dragon skin paddle then an eighty grit sanding paddle.

 

I bought the dragon skin at a camping store???   about 10 years ago, bought
a couple of sheets made a few paddles and have used

them ever since, probably will last a lifetime.

 

Best,

Jack Houweling

 

 

 



 

  _____  

From: pianotech-bounces at ptg.org [mailto:pianotech-bounces at ptg.org] On Behalf
Of David Boyce
Sent: Sunday, March 13, 2011 12:19 PM
To: pianotech at ptg.org
Subject: Re: [pianotech] Cosmetic aspects of filed hammers

 

Thanks for your responses folks.

Alan, you say



 

David, 

Did you remove the hammers and place them in groups in a vise to dress the
hammers, or do them in situ?

On this 1883 Bechstein I used French chalk to whiten the hammer surfaces and
then vigorous brushing with a nailbrush.

I did them in situ. I've never removed a sert of hammers just for filing. 
In what form was the french chalk you used? One of the little
rectangular-profile sticks?

I think your screwdriver idea is great! It exactly solves what I observed to
be the problems with the mini-drill tool. That is, lack of torque means that
1) it's hard to keep a constant speed and 2) you can only use a wheel of
small diameter.  The power screwdriver/sandbobbin approach solves both
problems! A power screwdriver is bound to have MUCH more torque than the
mini drill.  Can I ask what glue you use to stick the sandpaper to the
bobbin?

Also, you mention interestingly that you use the same setup but with steel
wool on the bobbin, to revive strings.  How do you attach the steel wool?

Joe, thanks for your comments 

In the hand-filed photo, I was taught to start the filing further towards
the tail than you did;  I start at least before the widest point, and often
before or at the staple.  The reason for this is that if you start after the
widest point (if you start closer to the crown), you are effectively
increasing the hammer radius at the crown, thus flattening the hammer crown.
This is illustrated by the exaggerated photo below. 

I appreciate exactly what you mean. I do try to keep a proper profile,
though I've never started as far back as the staple.  The idea of taking off
a layer or "skin" of felt all the way round would certainly solve the
problem of the grubbiness on the upper surface.  Mind you, there is the
aspect of time and cost, related to the quality of the piano.  In the
particular example I sent, and for that particular section of hammers, the
filing does start nearer the nose the I usually would, but for those hammers
it kept the profile OK.  I love the idea of frantically trying to glue back
on excess removed felt!  I can't guess the brand of piano, by the way!

John Ross, I do like the idea of using the sand blaster with glass beads.
I've been thinking for a while about a compressor.  What else do you use the
setup for, in addition to cleaning actions?

Jack, you say 

I have a special paddle I use, it is a piece of dragon skin I glued onto a
paddle. It takes the felt off very quickly. I then go on to finer grits with
various paddles

and sandpaper strips finishing off with 600 grit.

Do you start right back at the staple, and take off a layer of felt all the
way round, as Joe recommends? It's really the "cleaning" aspect that I was
asking about.  I wasn't familiar with dragon skin, so looked it up.
Interesting. Where do you obtain it?

Thanks again folks.

Best regards,

David Boyce

-------------- next part --------------
An HTML attachment was scrubbed...
URL: <https://www.moypiano.com/ptg/pianotech.php/attachments/20110313/3f3a26c2/attachment-0001.htm>
-------------- next part --------------
A non-text attachment was scrubbed...
Name: image001.jpg
Type: image/jpeg
Size: 17114 bytes
Desc: not available
URL: <https://www.moypiano.com/ptg/pianotech.php/attachments/20110313/3f3a26c2/attachment-0002.jpg>
-------------- next part --------------
A non-text attachment was scrubbed...
Name: image002.jpg
Type: image/jpeg
Size: 18131 bytes
Desc: not available
URL: <https://www.moypiano.com/ptg/pianotech.php/attachments/20110313/3f3a26c2/attachment-0003.jpg>