oversize pins in a doped block

[David Love]

If the block has been doped I think you need to replace it.  You can't ream
enough material to get rid of the contaminate and leave you with a small
enough diameter to use a reasonably sized pin.

David Love


----- Original Message -----
From: "Mike and Jane Spalding" <mjbkspal@execpc.com>
To: <pianotech@ptg.org>
Sent: May 27, 2002 7:58 PM
Subject: oversize pins in a doped block


> List,
>
> 30 year old Story & Clark baby grand (model 152) by Yamaha.  The entire
block was glycerin doped, additionally the bass pins were driven in until
the strings started breaking from binding on the plate.  That's when the
owner started looking for another tuner, and I was the lucky winner.  I will
be restringing the bass using oversize pins, probably Paul Larudee's stepped
pins.
>
> I have some experience reaming and selecting the appropriate size pin, but
never in a doped block.  The original .272 pins were holding pretty well,
but very jumpy (and noisy when I powered them out).  I'm wondering if the
small amount of material normally removed in reaming will result in normal
tuning pin feel?  I would appreciate some suggestions on how much to ream,
and how much oversize to go with the pins, given the doped block.
>
> Also, this is my first restringing involving tuning pin bushings.  Schaff
sells bushings with 7/32" bore, Pianotek's have 1/4" bore.  Do either of
these need to be drilled before I drive the pin through?  I can see where
1/4 would probably be OK, but 7/32 would be pretty tight especially on an
oversized pin.
>
> thanks,
>
> Mike Spalding, RPT
>
>