Bridge gain delamination

[Don]

Hi Terry,

Some grands don't have bridge caps. Therefore the vertical laminations are
quite accesseable.

At 11:21 AM 8/1/00 -0400, you wrote:
>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
>>
>
>
>
Regards,
Don Rose, B.Mus., A.M.U.S., A.MUS., R.M.T., R.P.T.
Tuner for the Saskatchewan Centre of the Arts
drose@dlcwest.com
http://donrose.htmlplanet.com/

3004 Grant Rd.
REGINA, SK
S4S 5G7
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