<HTML>In a message dated 12/19/2002 4:42:57 PM Pacific Standard Time, mfarrel2@tampabay.rr.com writes: <BLOCKQUOTE TYPE=CITE style="BORDER-LEFT: #0000ff 2px solid; MARGIN-LEFT: 5px; MARGIN-RIGHT: 0px; PADDING-LEFT: 5px">Subj: Soundboard Clamping for Downbearing Date: 12/19/2002 4:42:57 PM Pacific Standard Time From: <A HREF="mailto:mfarrel2@tampabay.rr.com">mfarrel2@tampabay.rr.com</A> Reply-to: <A HREF="mailto:pianotech@ptg.org">pianotech@ptg.org</A> To: <A HREF="mailto:pianotech@ptg.org">pianotech@ptg.org</A> Sent from the Internet        Terry</BLOCKQUOTE>            Well, it certainly is way easier to do the bridge notching / pinning, etc., out of the piano.   So I do the dry fit set up this way. In my climate I like the board to have taken up some moisture but something like it would experience with the R. H.  about 40% or EMC about as you said 9% or so. I locate and temporarily install my bridge to the board with soundboard buttons and screws, one between each rib and one through only the ribs in the low tenor that have the feet thing and cutout between them. Usually that's only 2 or three. I Install the board dry by drilling holes for dry wall screws thru the board and into the rim where the acoustic dowels were located. No magic here. These holes will eventually disappear when the holes for acoustic dowels are drilled or fill them with hammer shank if a different support system is used.   Next install your plate with the nose bolts for support. Install about 8 or 10 screws in the pinblock, usually next to each strut. I set the plate so its elevation at the last bass end bolt hole is where it was originally which means the plate boss is fairly close to the board. I have a shim between the boss and the board. I put a clamp and block holding down the plate to prevent it from coming up in the bearing procedure.     I then turn up my nosebolts which were installed low. This includes the bass strut nose bolt and cap nut too. I pre-stress the board with a shim at each plate strut to simulate some string load as I've described before. I Cut my bearing notches to determine where the bridge height will be. Pull the plate & board plane the top of the bridge reinstall check and make final corrections to height and bridge slope. Pull it out remove the bridge, drill, notch & pin and the other details.     After the board is glued in I always recheck my bearing and adjust my plate a bit if needed. This is a great method but you'll find your board ever much stiffer when you go thru the pre-stress bearing check at this point because the bridge and board have been glued on and everything has gotten stiffer. Which means your bearing may be more than you bargain for. With this method I've learned to set the distance bearing on the stingy side especially from about note 60 ish on down. With Steinways it's possible to shim aliquots up if too much bearing is attained. Flexing the plate up with the nosebolts is good for about 1/4 turn max. in my book with Steinways and none in Masons as the plates are too stiff to flex.        Hope that helps         Dale Erwin     <BLOCKQUOTE TYPE=CITE style="BORDER-LEFT: #0000ff 2px solid; MARGIN-LEFT: 5px; MARGIN-RIGHT: 0px; PADDING-LEFT: 5px"> One thing I have never been able to clearly picture in my head (or rather, one of many). If I wish to notch the bridge outside the piano, I need to temporarily mount bridge to board, set board into case and set plate at final resting height (on dowels or adjustable bolts, etc.). When I have the plate in, how do I clamp the board down to the rim securely for determining final bridge height? At what MC do I have the board for this procedure (I would assume equilibrated with room RH - maybe 9%)? Looking a step further, if I then dry the board down prior to installation and then glue the board to the rim, can I be pretty sure the board will crown right back to the test height when I measured for bridge height? Just can't get this process straight in my head where I can see that all will work out. Thanks for any thoughts. Terry Farrell </BLOCKQUOTE> </HTML>