Bridge gain delamination

[Farrell]

Roger: O Yee of Great Wisdom. I read these posts with great interest, always
trying to learn about a situation before I run into it. In the post below,
if the vertical laminations on the bridge have delaminated (I assume we are
talking the main portion of the bridge below the bridge cap) and the bridge
cap is not cracked, how do you get epoxy into and spread around in the
vertically delaminated areas - isn't the bridge cap covering all this,
rendering the delaminated area inaccessable???????

Terry Farrell
Piano Tuning & Service
Tampa, Florida
mfarrel2@tampabay.rr.com

----- Original Message -----
From: "Roger Jolly" <baldyam@sk.sympatico.ca>
To: <pianotech@ptg.org>
Sent: Monday, July 31, 2000 10:35 PM
Subject: Re: Bridge gain delamination


> Hi Patrick,
>                 I am assuming that the splits are only in the vertical
> laminations.
> I have successfully repaired a number of Baldwin vertically laminated
> bridges with separations.
>
> You need a few cabinet makers wooden handscrews. ( the wooden clamps with
> two handscrews)  The points of the jaws will allow you to slip down
between
> the side of the bridge and the plate.  Or you can modify them on a band
saw
> so that you can get a good grip on the sides of the bridges..
>
> Remove enough strings to give you room to work.  Dry clamp the offending
> area and see if you can draw the split together, usually no problem.
>
> Remove the bridge pins that have hair line cracks.
>
> I use West System thin epoxy. Swab the pin holes, and the split.  Install
> new bridge pins.
> Tighten clamps.  Clean excess with acetone.  Leave for 24hrs to cure.
>
> If you have not used wooden handscrews. You need to practice a little
> before you start.  They have a good deal of clamping power once you get
> used to them, and are less prone to marking or denting your work.
>
> Replacing the bridge pins is a personal fetish for this type of repair.
But
> the pin will act like a pump and fill your small cracks from the bottom.
>
> I presume the bridge cap is not cracked.
>
> Hope this is of help.
>
> Roger
>
>
>
>
>
>
> At 11:57 AM 31/07/00 -0400, you wrote:
> >Dear List:
> >I just returned from a piano evaluation, for a customer looking to buy a
> (32 year
> >old) small model 350 Kawai grand, walnut veneer, for $4500. Everything
> looked AOK
> >EXCEPT:
> >the bridge gain (cf. Mason, he also calls it the bridge core; I'd call it
the
> >bridge body) is separating along the diagonal joint 3-4 notes above the
> >tenor/treble break. There's minor cracking of the bridge surface at the
> bridge
> >pins, but there's clearly been some glue joint failure at the joint in
the
> body of
> >the bridge (the sides of the bridge are no longer flush, the joint line
is
> too
> >prominent). No tonal deficiencies because of it (yet).
> >I'm (optimistically) thinking I could fix this in the home by running
> screws with
> >washers through the separated parts, soak epoxy into the slight but real
> >separation, etc. I'm hoping that with 2-3 sessions the bridge should be
AOK.
> >Have any of you had success with this kind of repair on other Asian
pianos
> (I've
> >seen this as a problem area on all of their long bridges)?
> >Or should I tell my customer to back out of the deal?
> >Comments, Jim Jon Ron Roger et al?
> >
> Roger Jolly
> Saskatoon, Canada.
> 306-665-0213
> Fax 652-0505
>