<HTML><BODY style="word-wrap: break-word; -khtml-nbsp-mode: space; -khtml-line-break: after-white-space; "><DIV><DIV>On Jun 11, 2007, at 4:34 PM, Dorothy Bell wrote:</DIV><BLOCKQUOTE type="cite"><SPAN class="Apple-style-span" style="border-collapse: separate; border-spacing: 0px 0px; color: rgb(0, 0, 0); font-family: MS Sans Serif; font-size: 9px; font-style: normal; font-variant: normal; font-weight: normal; letter-spacing: normal; line-height: normal; text-align: auto; -khtml-text-decorations-in-effect: none; text-indent: 0px; -apple-text-size-adjust: auto; text-transform: none; orphans: 2; white-space: normal; widows: 2; word-spacing: 0px; ">For me, in this discussion, emotions are too high, data too little and gathered in non-standardized manners so therefore not comparable, and applicability of the information to my work is too low.</SPAN></BLOCKQUOTE></DIV><BR><DIV><SPAN class="Apple-tab-span" style="white-space:pre"> </SPAN>The practical side of the discussion (which hasn't been the bulk of the discussion, by any means) has to do with how best to treat pianos so as to minimize humidity induced "change in tuning." Obviously the most reliable approach is to control humidity in the building, but that isn't feasible financially for most, and, from what we hear, whole building systems can be unreliable nightmares if not kept after. The next approach is to use piano-installed systems, which are somewhat, but by no means entirely, effective. Why not? This is where this discussion has really focused on something we deal with every day. If the "why not" has to do with bridges, as Ron N says (and I am pretty well convinced he is right), then perhaps there are ways to deal with bridges as well as boards. One way is in design and construction, as Ron is experimenting with epoxy impregnated bridge caps. </DIV><DIV><SPAN class="Apple-tab-span" style="white-space:pre"> </SPAN>For those of us who aren't recapping many of our pianos' bridges, another possibility is that some degree of saturation of bridges with extra thin CA might work to some extent along those lines (making bridges less hygroscopically active). Meaning we might go beyond just applying a bit next to the pin where there is a false beat, and also beyond the capo section. Just a thought, for a line of experiment. A first step would be to take an old bridge (or emulation thereof, outside a piano) do an application to a portion, leaving another portion as a control, and measure expansion and contraction in response to humidity change. Variants might include application of CA with pins in; removing pins, saturating the hole, replacing pins; doing the same with epoxy; epoxy with heat. </DIV><DIV><SPAN class="Apple-tab-span" style="white-space:pre"> </SPAN>And another possibility is to try to control humidity above the board, probably with some variant of a string cover. As has been noted, the Edwards string cover, fairly thick wool, has a bit of a damping effect. Use of a cloth similar to that provided by Dampp-Chaser for undercovers (so-called "speaker cloth" with a loose weave) might provide enough isolation to allow for the under-board system to create an environment that extends above. </DIV><DIV><SPAN class="Apple-tab-span" style="white-space:pre"> </SPAN>Anyway, those are a couple thoughts on the practical side. Thoughts are cheap. Action and documented results are rare and valuable <G>.<BR><DIV><DIV>Regards,</DIV><DIV>Fred Sturm</DIV><DIV>University of New Mexico</DIV><DIV><A href="mailto:fssturm@unm.edu">fssturm@unm.edu</A></DIV><DIV><BR class="khtml-block-placeholder"></DIV></DIV><BR></DIV><DIV><BR class="khtml-block-placeholder"></DIV></BODY></HTML>