----- Original Message ----- [link redacted at request of site owner - Jul 25, 2015] To: <davidlovepianos@earthlink.net>; "Pianotech" <pianotech@ptg.org> Sent: July 22, 2003 11:59 AM Subject: Re: soundboardinstal again > I suppose if you > didn't use the wedges you may not notice this. I've pre-stressed many a board and still have not noticed this. We dry-fit our boards by screwing them down without glue around the parameter. We then check string bearing, do our bridge work and establish a plate height. When all is as we want it we glue the board in, finish it and set the plate back to the same elevation established during the dry-fit. We generally end up with the expected string bearing with no further adjustment. I do agree, though, that a soundboard might well be moderately stiffer with the parameter glued than it is while simply screwed down. A clamped-edge panel will always be somewhat stiffer than a semi-clamped, or semi-floating panel. It would be some difficult to screw a board down tightly enough to qualify as a truly clamped-edge panel. Trying to predict just how much stiffer it will become brings in a number of variables, including how tightly it was screwed down, how thick the panel is, how thick the ribs are, the stiffness of the various materials, the crown radius, etc. A couple of things to keep in mind: -- This phenomena is noted whether the panel is crowned or not. In other words, with all other factors remaining the same, it will be similar with both a crowned panel and a flat panel. -- Soundboard panel stiffness and the ability of a given soundboard panel to retain crown over the years are two different things. Del Del
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