<HTML>In a message dated 1/19/2002 1:51:33 AM Pacific Standa= rd Time, JD@Pianomaker.co.uk writes: <BLOCKQUOTE TYPE=CITE style="BORDER-LEFT: #0000ff 2px solid; MARGIN-LEFT= : 5px; MARGIN-RIGHT: 0px; PADDING-LEFT: 5px">Subj:Re:y own Soundboard </B= > Date:1/19/2002 1:51:33 AM Pacific Standard Time From:<A HREF="mailto:JD@Pianomaker.co.uk">JD@Pianomaker.co.uk</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 .   J D Writes As to the crown in the other direction, I'll quote from Wolfenden, writing in 1916:    "Modern practice all over the world, aims to put the board itse= lf into a state of compression, to that it is constantly acting to assist the bars [belly bars = American: ribs] to do their duty.    The writer's own formula is: Arch the bars to about the usual <= BR> curvature [60 ft radius], keep the board warm at say 100° to 120° F. <BR= > for a few hours to shrink it.   Place it on a frame or board hollowed out a trace deeper than the <BR= > curve of the bars, and while the board is hot, glue the bars down.    When the pressure is released, the rounding will be greater tha= n the original curvature of the bars, and the board in a considerable state of compresssion, which it will retain and which will increase a little.    The backs of the bars which by this process become a little hol= low in the length, are afterwards planed straight.    The whole structure thus becomes a highly elastic spring" >  </BLOCKQUOTE><BR= >    Hi JD I totally agree with Samuel= and can relate having made many boards this way with the exception that his= drying method is archaic and unpredictable or just not clearly presented. A= s he subscribes to cutting 60 ft. radius ,which is good, it however needs to= be coupled with more predictable and moderate E.M.C in the panel after dryi= ng. I however no longer think it a must that the caul or dish radius be grea= ter than the radius of the ribs. Even with 60 ft. soundboard cauls or dish a= nd drying to 30% R.H./6 % emc,  the long ribs will still hollow a bit. = If its tooooooo dry using his method one would still end up with too much pa= nel compression and defeat the purpose of significant rib crowning by introd= ucing the destructive crushing cycle again. <BLOCKQUOTE TYPE=CITE styl= e="BORDER-LEFT: #0000ff 2px solid; MARGIN-LEFT: 5px; MARGIN-RIGHT: 0px; PA= DDING-LEFT: 5px"> You wrote For gluing the belly bars, I'd forget about clamps and pneumatic arrangements.  Good old go-bars are fast and efficient and you can easily construct a gluing press that can be quickly dismantled when you're not using it.  Some of the German makers have invested millions in fancy machinery for special tasks but there are cheap and efficient traditional ways of doing almost everything.  All the finishing work on the bars is done with a hand plane and good pre-1914 chisels. ></BLOCKQUOTE>         WoW JD Have you used a go bar dec= k verses a fire hose press? I've used both and find the go bar deck (I still= have a very nice one)all though possible and feasible with good results. Ho= wever  superior glue joints occur with the absolutely even pressure of = air. Less glue applied to get glue coverage in the  joint and way less = glue squeeze and clean up. Also the setup time and teardown time is less. <B= R>    Physically  go bars are more demanding and more dangerous = ,Crack split oh wow there is another rsoundboard dent to fix as the bar slid= es off . No more ribs sliding around when the first go bar presses to the ri= b. See what I mean? <BLOCKQUOTE TYPE=CITE style="BORDER-LEFT: #0000ff 2px solid; MARGIN-LEFT= : 5px; MARGIN-RIGHT: 0px; PADDING-LEFT: 5px">I'll write an article one day o= n sharpening knives, chisels and plane irons so that you can shave with then and tell you a story of how I was too clever by half when demonstrating these skills to an apprentice!  J D   </BLOCKQUOTE>             &nbs= p; J D I'd Love to see thi= s in print. Always new tricks or old to sharpening.        Best--Dale Erwin <BLOCKQUOTE TYPE=CITE style="BORDER-LEFT: #0000ff 2px solid; MARGIN-LEFT= : 5px; MARGIN-RIGHT: 0px; PADDING-LEFT: 5px">JD </BLOCKQUOTE> </HTML>