The plate in a 243 is not as strong as it could be nor is it weak enough that can be bent to any degree, as described, without breaking. Cast iron is flexible over a long distance but not over such a short distance as from plate top and pinblock bottom. It just isn't going to happen. When restoring a grand piano we are careful in the extreme to NOT put undue strain on the plate and extremely careful to set the plate so we get good bearing and superior support. This includes raising or lowering the pinblock in order to get proper elevation for good stability and good bearing. In this piano the degree of separation is extreme and _any_ displacement from the factory setup will indeed effect bearing, tone, sustain and likely durability. Pulling the crack as closed as is humanly possible without totally dismantling the piano is the goal and leaving any gap through inattention or indifference is doing the owner and the piano a major disservice. Factory assembly as under best possible conditions. That luxury is not available so we absolutely must do the best possible to return the piano to as new specifications and condition. There has been a lot of good ideas on this thread and your is a good question. The how nots are as important as the hows. Newton kam544@flash.net wrote: > > >...As Newton said, closing the gap IS important for downbearing... > >Bill Shull, RPT... > > Since you have chosen to support Newton's comment, would you, or Newton, > care to explain how downbearing will be affected if the gap is not > completely closed, yet made completely stable with the repair suggestion I > gave. > > Please keep in mind the original post indicated: > "...If you draw a line from the pressure bar in the high treble, extending out > to the edge of the plate, this is where most of the bend occurrs (at the > base of the pinblock)..." > > Keith McGavern > Registered Piano Technician > Oklahoma Chapter 731 > Piano Technicians Guild > USA
This PTG archive page provided courtesy of Moy Piano Service, LLC