This is a multi-part message in MIME format. ---------------------- multipart/alternative attachment David Love wrote: > It's unfortunate that there isn't more research on regulating humidity within the action cavity itself. =20 Hi folks, I've been following this discussion and decided to chime in. It's my believe that where pinblock failures have been attributed to = this heat, moisture problems over many years caused both action = problems, and pinblock delamination with hide glue blocks. Probably = tuners used uncontrolled heat to make a dent in a frozen action, and = that worked against a weak, delaminating pinblock. Negative responses = to that situation are understandable. But David has raised several good = arguments, and I agree with his conclusions, and go a little further. We have installed many DC rods in grand actions. It is not an everyday = part of our installations, but it has a definite place in the arsenal = when you're looking for effective and safe humidity control. This is = the key: it absolutely MUST have its own control, and it must be placed = where it will get good feedback. We install the humidistat next to the = #1 bass string, on the rim, with the sensors down. This is above the = action cavity, so as the heat rises it will be read and turn the rod = off. We have always used the 8 watt bar for this purpose. =20 The area where we work has every humidity situation you can imagine. = Most homes experience wide seasonal swings due to our sea level and = proximity to lots of water, followed by cold winters and central = heating. Individual homes may have pianos next to large radiators, = simulating the desert environment. Others are on heavily wooded lots = and never dry out, simulating the tropics. Our clientele have = everything from spinets to concert grands. So over the years, I doubt = there is a situation we haven't had to address. =20 It is understandable that Dampp-Chaser takes the position it does. = People will hear that it's okay to use a rod in the action, and go back = to 25 watts plugged in to the wall outlet. Don't Do That! It's a = small, enclosed area, and it doesn't take much to do the job. =20 If the action screws get loose from this, it's because the wood was = swollen, and you've brought it back down. Tighten them once and they'll = stay put. It's like expecting a pitch drop after an installation, if = the soundboard was swollen. If the regulation changes, let it, then = regulate, and it will be stable. =20 Incidentally, if you run across the old brown humidistats, they are good = for this use as you only need the dehumidifier side plug. An 8w rod is not going to undo years of neglect, as it is preventive in = strength. As soon as I see any warning signs, I go for that = rod/control. It is a "booster shot" for extreme situations where the = humidity is very high and performance requirements equally high. I addressed this subject in a Journal article many years ago, probably = at least 10. By then, we had long been using multiple rods in most = every installation. A 36-15 or 36-25 under the keybed is a standard = part of our grand installations and has been for decades. That one can = safely be connected to the control under the soundboard. I also recommend and sell the string covers made by Judi Edwards. They = will add greatly to the stability of an installation. A good policy is to always tie the wattage to the situation. Eight = watts is so gentle that it will not blast the humidistat and be shut off = immediately. Too much wattage in that area will overdo the heat, then = shut off and take a long time to come back on. The best way for all of = this is to get even and consistent cycling. This requires good feedback to the control, and the correct wattage. Negative comments on this subject are very understandable given the = misuse of the rods over the years. But I think that, with where = Dampp-Chaser has gone, and the general acceptance the subject finally = has, this is a timely discussion. =20 When I started working with Webb about 25 years ago, he was already = doing all these things, so I was no innovator, but I did imitate a good = thing and have not had a single problem with these action dehumidifiers = in all that time. =20 Happy Labor Day - take the weekend off! Ruth Phillips ---------------------- multipart/alternative attachment An HTML attachment was scrubbed... URL: https://www.moypiano.com/ptg/pianotech.php/attachments/3f/a9/8f/ec/attachment.htm ---------------------- multipart/alternative attachment--
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