Hi Ron, You bring up an interesting question. I have taken old sections of soundboard and sawed shims out of them. The reasons I did so may or may not have been good ones. (I haven't shimmed a soundboard since I replaced my first one. I guess it spoiled me.) When we were doing more shimming, we used to dry the board out a bit, (I don't think we had a specific RH or MC), put wedges underneath between the board and the beams to force it up, and then start shimming. We would open up the cracks on the top side of the board as nicely and evenly as we could with a tool that made a nice V-groove the right shape for a shim to go in. We almost never had need of a shim that went all the way through the board, so the old shims were tall enough for what we were doing. We would glue them in, and then when the glue was dry, take a sharp chisel and smooth them out flush with the surface of the board. What we were doing would probably have been considered more of a cosmetic repair. The initial attempt at making the shims from old soundboards had nothing to do with expense. We had two problems that we thought we might be able to help with. The first was appearance. The new shims we were getting were very white wood, and stood out on the old boards. We thought that perhaps the old wood might have a little more color. It did tend to have a little more color, but was still whiter than the surrounding board. The second thing that was bugging us was that the new shims did not come to a point on the bottom. They were often too wide to get into smaller cracks that we didn't want to open up far enough to get the new shims into. The shims that I cut out were almost as tall as the old soundboard was thick, and most all of them had a nice sharp edge on the bottom. I don't know if these were good or bad. I do know that the other techs gravitated towards those shims. It seemed that given the choice, they always picked up the ones I had cut out. I think they are used up by now, and I never did make any more. Like I said, I got spoiled putting in new boards. If I were to start shimming again, which I will probably do at some point, I may re-evaluate my methods of shimming, and perhaps the new shims might work better with a new method. Interesting thoughts though, Ron. Glad you piped in. Brian Trout Quarryville, PA btrout@desupernet.net ----- Original Message ----- From: Ron Nossaman <nossaman@SOUTHWIND.NET> To: <pianotech@ptg.org> Sent: Monday, December 06, 1999 11:53 PM Subject: Re: Shims and soundboardrepair. > Danny, > The old wood has also been under compression for a lot of years and has > suffered some accumulated compression set. Actually, I doubt that there is any > harm at all in using old soundboard material from one board to shim old > soundboard material in another. I doubt that there is any benefit either, but I > don't see any harm. The salvageable portions of the old panel will be the > planks that haven't failed to the point of cracking, and if the board being > repaired still has some crown under string bearing load, and the budget doesn't > allow soundboard replacement, then why not? The shim material will be of about > the same degree of deterioration as the board being shimmed. Of course, the > fact that the board being shimmed *is* being shimmed means that it has > deteriorated enough to crack in the first place and is at least somewhat > suspect. I have a question though that is more practical than judgmental. If > you have a cracked panel that is quarter sawn, and want your shim to have > roughly the same grain orientation as the panel, how are you going to cut shims > that are both deep enough, and with the proper grain orientation out of an old > quarter sawn soundboard panel without laminations? > > > > Ron N >
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