Hello Will, That looks like Bubinga that they've used in the laminate that's split. I've seen this before on Steinway laminated bridges. Bubinga can be pretty cranky stuff, and I believe its less than ideal for making vertically laminated bridge stock. Is the grain direction out of alignment in the laminate that's failed? It usually is. The colour contrast might look very nice, but if it has a high propensity for failure why use it? You could drive some west system epoxy into the cracks. Drilling a few suitably spaced holes along the line of the Bubinga laminate, which are sized to be a slight interference fit with maple hammer shanks, might be a good way to inject glue to the bottom of the cracks. Drill the holes to the depth of the cracks, fill the holes with epoxy and drive the hammer shanks home to the bottom of the holes. You'll in effect be filling the cracks from the bottom up. The bridge root will be slightly spread where the laminate has failed. It would be best not to clamp it up until after the dowels have been driven home. If the bridge is clamped together immediately after gluing, you'll get a good result. If you've got a veneer trimmer you could set the fence along the convex side of the bridge to route out the Bubinga and replace it with something decent like Rock Maple. This might also be quicker than plugging, and it would remove the failed laminate, which will almost certainly be cross grained at the point of failure, from failing again at some later time. Ron O >To the list: > >Enclosed is a picture of the root of the treble bridge for the 1909 Steinway >A2 in my shop that I am rebuilding. I'm almost ready to glue on the bridge >caps to the root. As you can see in the picture, I have plugged the bridge >pin holes with the small dowels that you get from Pianotek. But you can >also see that in the high treble on the backside, the laminations have split >for about 5 or 6 unisons. I am not satisfied that the plugs I inserted >there are going to give the bridge and pins the integrity they need, so I am >searching for a plan B to fill the offending space. > >My thought is to cut some plugs out of bridge stock and glue them in. The >idea would be to make the plugs slightly larger than the three pin holes, >drill the holes, and epoxy them in. > >Before I do that, I would be interested in the suggestions of others as to >their go-to methodology. > >Will Truitt > >Attachment converted: Powerbk HD:DSC00168.JPG (JPEG/«IC») (00B999D8) -- OVERS PIANOS - SYDNEY Grand Piano Manufacturers _______________________ Web http://overspianos.com.au mailto:ron at overspianos.com.au _______________________
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