Tom: Drill as many pilot holes with a small bit through the rib and soundboard on both sides of the crack as far as the rib/soundboard separation extends along the rib; the holes can be two, three, or four inches apart. Use a soundboard steel between the rib and soundboard as a stop and drill a 1/4" or 7/32" hole to accommodate a screw which will go through the rib without binding and extend a good quarter inch above the soundboard surface. Clean out rib/soundboard join with a side sharpened putty knife (take a 1" knife and sharpen a side edge on a belt sander). With a good spatula, apply carpenter's glue into the join between the rib and soundboard as far into the separation as you can. Install the screws with a washer to protect the rib surface starting from the farthest located hole in the rib from the crack; this will gradually pull the board and rib together without putting undo strain on the board or rib. Clean up all glue squeeze-out, please (I've seen so much sloppy repair over the years). Give it overnight to really setup. Remove the screws and with the same small bit you drilled the pilot holes carefully open up a small glue releasing hole in the soundboard. Plug the holes in the rib with either 1/4" dowel or 7/32" hammer shanks lightly tapping the glued plugs flush to the underside of the board. You should see squeeze-out on the soundboard surface. Clean up. Trim plugs flush with a fine Japanese flush-cutting saw, sand the plug end and rib to a smooth surface and zotz with shellac or lacquer; at least get some finish on the bare wood. You're done. The small holes in the soundboard can be cleaned and plugged from the top if you are concerned about appearance there. Paul Revenko-Jones "If you want to know the truth, stop having opinions" (Chinese fortune cookie) In a message dated 08/04/07 22:22:32 Central Daylight Time, tvaktvak at sbcglobal.net writes: That's easy. I could do that. The crack is visible. Thin viscosity CA glue would run right through the separation. Shouldn't I try to move the soundboard back into the rib first? With a clamp or something? Then apply the CA? Tom Dean May <deanmay at pianorebuilders.com> wrote: >>Tom Sivak’s problem piano The piano: an Everett studio console, about 30 years old. The client: one of my piano students. The problem: crack in the soundboard that makes a prominent, buzzy sound from about C4 to A5, with G4, G#4, and A4 being by far the worst. Below is what I posted back in May. Don’t worry about filling the crack unless you are concerned about cosmetics. If there is no visible separation from the ribs, just use the thin glue. If the gap is wide enough that the glue keeps running through then you might run a bead of the medium thickness glue in that area. If anyone else tried this you might chime in for Tom. Dean Dean May cell 812.239.3359 PianoRebuilders.com 812.235.5272 Terre Haute IN 47802 >>Dean, How do you treat ribs and rim on a grand with CA glue? Please describe the process. I think Don Mannino was the first guy to tell me about this back in the mid '80s as a warranty fix for some Young Chang grands that were having soundboard/rim separation issues. It was also my first exposure to CA glue. I was very skeptical, but he assured me it would work. And it did. Remove lid, put moving blanket down and turn piano on its side. Use a brush/vacuum to remove any dust/dirt coating on the ribs and soundboard rim. If you don't, the dust will absorb a lot of your glue before it gets into the joint. I like to first mist on accelerator on the tops of all the ribs and all the way around the soundboard. Without the accelerator you run the risk of the glue leaving the joint before it sets up. Using a full bottle of glue, squirt the glue vertically and generously into the rim joint around the top (you can't do this if the bottle is half empty). The capillary action of the glue will suck it vertically into the joint (it is an amazing thing to behold). BTW, if you are working on an upright, do the same thing: start at the top rim of the soundboard and squirt vertically. Then do the ribs: starting at the top apply enough glue to the joint so it runs down the rib to the soundboard/belly rail joint (nomenclature police, please advise). As you observe the bead of glue running diagonally down the rib you may observe it disappearing into the joint. If this happens you've located an air pocket in the glue joint, or some separation between the rib and soundboard. Give it some more glue to fill up the pocket. If glue runs all the way through and comes out the bottom of the rib, spray accelerator along the bottom to set the glue up there and form a dam. In severe cases I'll spray accelerator generously on the top as well to set the glue up quicker before it runs out of the void. Try to run enough glue down the rib so that it will also cover the sndbrd/belly rail rim joint. Then do the rest of the rim along the bottom and back curve. Do a final misting of accelerator everywhere you squirted glue and wait 15 seconds. You don't want any unset glue running out when you set the piano upright- DAMHIK. Then set the piano up and you're good to go. If you have a case of severe separation you may want to use your favorite method of pulling the joint together before applying the glue. If it is an old clunker and you just want to eliminate the buzz it isn't really necessary. For an average piano, I use about 1 oz. For severe cases, 2-4 oz- sometimes I'll even use thick CA if there is a lot of separation and I'm not pulling it together. The same process will also work for loose bridges/pins, especially the aprons on bass bridges. I've also spoken to a tech that claims it fixed a grand with a dead section that apparently had a void underneath the bridge. I've done this procedure for 15 years now and never had a buzz return that I know of. If you are also going to CA treat the pins, go ahead and turn the piano upside down and apply from the bottom of the tuning pin hole. I use no accelerator for this as I want the glue to soak into the wood. You will of course need to remove the fall board and action before you do this. Don't use any more than 2 oz for this pin treatment. You'll waste glue or worse (much worse), it will run out in places where you don't want it to. Dean Dean May cell 812.239.3359 PianoRebuilders.com 812.235.5272 Terre Haute IN 47802 -------------- next part -------------- An HTML attachment was scrubbed... URL: https://www.moypiano.com/ptg/pianotech.php/attachments/20070804/66188fa1/attachment.html
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