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hi
i have upright piano and i found a long crack on my sound board.
i have a few keys that whistle.
the tuner said that the crack cash the whisle.
i didn't want to fix the crack.

how to fix the crack?
i saw 2 types of fix:
1. by putting a wood shims and glue in the cracks.
http://www.rayspiano.com/B-KnabeUpt1907_files/11-KnabeUpt1907BoardCracksShimmed030315.jpg


2. by putting a ribs with drill on the cracks.
http://www.stevespianoservice.com/crack.htm
http://www.stevespianoservice.com/57-sdbd2.htm


which way should i need to use?
how to do it?

thanks
Tomer

Usually the plate is removed to fix cracks by shimming. Steve is fixing the spot where the crack in the board passes over a rib. It's a good assumption that this is where the buzz or whistle is coming from. I would try Steve's method. Drill the holes from the back side, just deep enough to go completly through the rib but not into the soundboard. Then, using some hot hide glue or some warmed-up and/or thinned down cold hide glue, inject the glue into the hole and insert the screw. This will reactivate the old glue in the rib joint and assures that the loose wood joint that is whistling gets some glue. Basically the glue expands the effective working area of the screw and the screw is just the method of clamping. After you see where the glue squeezes out around the rib, you might want to do more spots on the rib than just the ones along the cracks. If you can find a small plastic Elmer's glue bottle with the round tip, that works great as an injector. Wash out the old glue, hide glue was probably the glue used originally so I would use only hide glue or the original glue.

kpiano

Thanks!
But what about by shimming cracks? i dont' wanna remove the plate, can i shimming cracks in the back of the piano? this way is more easy!

let's see if i understand you:
i just need to take a rib as the lenght of the crack (it's a long crack), to attach it to the crack and then just to drill a screws into the sides of the rib.

thanks.

No, this repair is done on the existing rib where the crack crosses the rib. That is where the buzz is coming from. The crack doesn't make noise unless it is thin and not separated. Paint the crack with epoxy or fill it with epoxy+filler and the buzz will go away.

Don't add another rib along the crack.

kpiano

Before you do anything, get another opinion. Most cracks don't cause problems, and problem notes are usually caused by other things. Check the easy things to repair before trying something difficult.

check what?
the problem is that a few keys are whistle