This is a multi-part message in MIME format. ---------------------- multipart/alternative attachment Another way to do it is to simply weigh a sample piece of spruce. Using = the electronic balance I use for action balancing work (goes to 0.01 = grams), I simply weigh one or two 100 gram or so pieces of spruce to = monitor when the weight, and hence MC, has stabilized. It may well be = that the samples stabilize a bit quicker than the panel because of their = smaller size, increased surface area and presumably more rapid rate of = moisture equalization, so just give the panel a little extra time. And = of course, like Ron N.'s excellent gauge, the samples would follow the = panel around.=20 One nice thing beyond the weight monitoring method's simplicity is that = you can use samples cut from the same stock you made the panel from. One = potential hitch using wood that is not from your current panel stock is = that the initial panel MC may be different from the gauge or whatever = else you are using (here again, the width measurement method eliminates = that potential problem). Let's say you have this very nice gauge that = you had in your hot box a month ago and it has been sitting in your shop = since then (should be pretty darn close to EMC in your shop - if you = keep your shop at a constant RH). You get your spruce from where? = Outside storage? The garage? Another tech in town? It may not be at the = same EMC with the gauge in your shop. Now if you buy a three year's = worth supply of spruce and store in inside your shop, perhaps you would = be OK, but you would be surprised how long it takes for a big piece of = lumber to come to an EMC with its environment - depending on how wet it = was to begin with - many, many, many months. Bottom line, you just = simply need to know what initial MC your wood is if you are using a = gauge. You can do that reasonably well by drying in an oven and weighing = (although I find the accuracy of this method to be a bit wanting). David initially asked about quick drying methods. I think monitoring = weight and/or panel width are fine methods, but I also think it is = advisable to be patient and give the system a little extra time to be = sure you have reached your target EMC. Employing two of these methods = would be good insurance. If you are really trying to do this quickly - = like you've got a tight production schedule - IMHO, you need a system = like Ron O's and some real good, properly used, electronic equipment to = accurately monitor the process. There is much known about kiln drying = wood. If you want to keep it simple, and I think any low-volume shop can = do that, you need to give a panel a week or two to dry and stabilize in = most situations. Terry Farrell ----- Original Message -----=20 From: "Ron Nossaman" <RNossaman@cox.net> To: <davidlovepianos@earthlink.net>; "Pianotech" <pianotech@ptg.org> Sent: Tuesday, November 11, 2003 12:03 AM Subject: RE: MC gage experiment >=20 > >Ron: > > > >I appreciate you offering this. If I may just clarify what might = seem > >obvious. Does this gauge, then, follow the panel around that you are > >working on? Once you have a reading for the size of your gauge at a > >specific MC, do you simply put the gauge in the hot box with the = panel and > >when the gauge reads your target then it must be assumed that your = panel > >has also? If that's the case, then I assume you take the gauge out = when > >the panel comes out and goes back in when the panel goes in. > > > > > >David Love >=20 >=20 > That's the idea. Instead of interpolating panel MC from the average of = > repeated temperature and RH% measurements, I now have a direct MC% = gage=20 > that responds at about the same rate as the in-progress panel. When = the=20 > gage hasn't moved over a 24 hour period, I can reasonably assume the = panel=20 > hasn't either, and I can thus be reasonably sure the panel MC is close = to=20 > the reading taken from the gage. I like tools that make life simpler, = and=20 > this is as idiot resistant a method of determining MC in a panel by=20 > independent but coexistent instrumentation as I've ever seen anywhere, = > supplying a nearly 1:1 direct analog mirror of the panel reaction to = humidity. >=20 >=20 > Ron N ---------------------- multipart/alternative attachment An HTML attachment was scrubbed... URL: https://www.moypiano.com/ptg/pianotech.php/attachments/e8/ea/f6/56/attachment.htm ---------------------- multipart/alternative attachment--
This PTG archive page provided courtesy of Moy Piano Service, LLC