> From: Paul Milesi <paul at pmpiano.com> > Date: November 16, 2011 1:11:20 AM EST (snip) > Now, while servicing the Life Saver system, I saw that the ends of all ribs > had been "modified" (chiseled?) near the rim. Hi Paul, I believe that the ribs have been modified to increase the length of the tapered section and add flexibility to the soundboard. I am not advocating doing so, but believe that this may have been the prior tech's rationale. Some luthiers string up a bowed string instrument in the white (before varnishing), and then adjust the graduation (thicknessing pattern) to improve tone, playing a little, scraping a little until they are happy with the instrument's response. We don't have that luxury, but adjusting rib taper does potentially afford us a little opportunity to address soundboard stiffness after the instrument is strung. I don't do so (since I don't have the skill do so safely while being sure to retain enough structural integrity to resist downbearing), wouldn't do so except in an experimental setting (before replacing an old board, for instance, or on a junker for learning purposes), and once again, am not advocating doing so. As for what to do about it, I would just seal the exposed grain with whatever the soundboard seems to be sealed with (shellac...), just to reduce the moisture exchange rate and prevent any hungry bugs from having an easy entry point into the wood, which looks little rough and has a bit of end grain showing (or, mitre grain, perhaps it could be called). > I also discovered a wedge > made of pinblock material under a rib at the belly rail towards the bass. > Isn't this inhibiting soundboard movement? Should I remove it? I'n not sure that the wedge is under a rib. Is that a bass cutoff? I can't tell from the picture, but since it seems to be parallel to the grain of the soundboard, it seems unlikely to be a true rib. If it is a bass cutoff, then I would guess that the wedge is there to stiffen it. Another (unlikely) possibility is that there was a loose glue joint somewhere among the cutoff/rib/board/rim, and the wedge stopped a buzz (we've all probably seen all manner of unlikely things shoved in to stop a buzz). In any case, I would listen carefully to the tone, then remove the wedge and listen to the tone again. If there is an improvement in the tone without the wedge or no change in the tone, then the wedge is ineffective (which is what I will guess) and should be added to your vast collection of useless objects once found inside pianos. I doubt if there will be degradation of the tone without the wedge, but if it comes to that, I suppose you can always put it back. If it does so happen that a buzz develops without the wedge, find and repair the loose glue joint properly, obviously. That's what I would do, anyway. I look forward to responses from some of our esteemed bellyheads. Joe DeFazio Pittsburgh P.S. - And, since I am now curious about what, if anything, might be different about the underside of the Blüthner board (the top sure does look different on the ones with the aliquot stringing, of course), I will be sure to crawl under the Blüthner I will tune next week.... -------------- next part -------------- An HTML attachment was scrubbed... URL: <https://www.moypiano.com/ptg/pianotech.php/attachments/20111116/bbf03ba9/attachment.htm>
This PTG archive page provided courtesy of Moy Piano Service, LLC