Bridge gain delamination

[Roger Jolly]

Hi Terry,
             that's what I was thinking, with a fairly thin bridge cap that
exposes the laminations at the notch.
 If it is an exposed vertical lamination like Baldwin then the fix I
suggested works well. If there is a cap and it is not split, how would you
see the seperation?

Mystified Roger


At 10:54 PM 01/08/00 -0400, you wrote:
>Yes, but in this case Roger was making the assumption that there was a
>bridge cap.....like in a Steinway......... "<I presume the bridge cap is not
>cracked.>"
>
>Terry Farrell
>Piano Tuning & Service
>Tampa, Florida
>mfarrel2@tampabay.rr.com
>
>----- Original Message -----
>From: "Don" <drose@dlcwest.com>
>To: <pianotech@ptg.org>
>Sent: Tuesday, August 01, 2000 11:51 AM
>Subject: Re: Bridge gain delamination
>
>
>> 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
>> 306-352-3620 or 1-888-29t-uner
>>
>>
> 
Roger Jolly
Saskatoon, Canada.
306-665-0213
Fax 652-0505