<!doctype html public "-//w3c//dtd html 4.0 transitional//en"> <html> <body bgcolor="#FFFFFF">   <p>Delwin D Fandrich wrote: <blockquote TYPE=CITE> <div dir=ltr><font face="Comic Sans MS"><font color="#000080"></font></font> </div> <blockquote dir=ltr style="PADDING-RIGHT: 0px; PADDING-LEFT: 5px; MARGIN-LEFT: 5px; BORDER-LEFT: #000080 2px solid; MARGIN-RIGHT: 0px"><font face="Comic Sans MS"><font color="#000000">So assuming that Climatic conditions can get over stress even an RC panel... I just was musing if there was some way of contiving a rib that gave crown support, but was a bit less constraining to the panels tendancy to expand and contract across the grain.... sort of sliding ribs if you get my meaning...Probably a silly question I know... but I was just curious.</font></font></blockquote> <div dir=ltr><font face="Comic Sans MS"><font color="#000080">Well, sure. I expect you could somehow slip-joint the panel to a set of crowned ribs much like a solid wood table top is attached to its frame. Theoretically, at least. I expect there might be the random buzz or two in real practice.</font></font></div> <div dir=ltr> </div> <div dir=ltr><font face="Comic Sans MS"><font color="#000080">Del</font></font></div> </blockquote> <p>Hi Del... actually... I was rather thinking (again perhaps another one of those bunny trails...) that perhaps one could add about a 1/8th inch thick strip of left over sounboard material to the top half of the rib, grain in the same direction as the panels. If it was dried to say 6.5 MC prior to attachment to the rib... and the soundboard was dried to say 4.5 MC why wouldnt this tend to sort of buffer the ribs cross grain constraint ? When taking on humidity this layer would get slightly compressed by the rib... and since its grain is in the same orientation of the panels it wouldnt force that into nearly as much compression.... er.. I think :)... If there was not enough crown you could rib crown enough to make up the difference. I suppose you could rib crown to begin with.. but if this provided a kind of solidly glued  << slip joint >> , and if there was some good reason to dry out the panel to 4.5 MC as long as one could avoid exceeding the stress limits... well... Anyways.. I'm just fooling with ideas in attempt to better sort out what does and doesnt happen. yes ?? <p>RicB <br>  <br>  <br>  <br>  <br>  <br>  <p>-- <br>Richard Brekne <br>RPT, N.P.T.F. <br>UiB, Bergen, Norway <br><A HREF="mailto:rbrekne@broadpark.no">mailto:rbrekne@broadpark.no</A> <br><A HREF="http://home.broadpark.no/~rbrekne/ricmain.html">http://home.broadpark.no/~rbrekne/ricmain.html</A> <br><A HREF="http://www.hf.uib.no/grieg/personer/cv_RB.html">http://www.hf.uib.no/grieg/personer/cv_RB.html</A> <br>  </body> </html>