This is a multi-part message in MIME format. ---------------------- multipart/alternative attachment "I think what Dan is trying to describe to you is simply that if the = "hole" wasnt there... then what would happen to the same area of wood = around that hole ? Why should that react differently, or why shouldnt it = ? Think about that as well when you drill your test piece tommorrow. :) = " Keeping in mind that I am simply trying to understand and make sense of = this, my reasoning is as follows: If the hole was not there, that area = of the hole would expand and get larger, just as he indicated. AND, if = the hole is not there, then wood is there, and wood expands with = increasing moisture content, causing the area in which it resides to get = bigger. BUT if there is a hole there, then there is no wood there, and = the wood around the hole will expand, thus closing off the hole (or at = least moving in that direction). So, yes, it should react differently, = because a hole reacts differently than wood, and wood next to a hole = will be able to expand/contract in a different manner than wood next to = wood. And I will think about all of that while I drill my hole. I might = even drill two holes. I might even drill several holes of different = sizes. So there! AND I will also be thinking about what a pleasure it is to interact with = other technicians on topic such as these to gain better understandings = of our work. This is the kind of thing that when we keep to ourselves in = a little cocoon, errant thoughts will remain and perhaps multiply = indefinitely. Of course I know that sometimes we don't solve a darn = thing and only generate more fodder for argument, ah, er, I mean great = discussion. Thanks for all the input. I'll report back with results! Terry Farrell Piano Tuning & Service Tampa, Florida mfarrel2@tampabay.rr.com ----- Original Message -----=20 From: Richard Brekne=20 To: pianotech@ptg.org=20 Sent: Tuesday, January 02, 2001 2:45 AM Subject: Re: moisture in wool or wood. I think what Dan is trying to describe to you is simply that if the = "hole" wasnt there... then what would happen to the same area of wood = around that hole ? Why should that react differently, or why shouldnt it = ? Think about that as well when you drill your test piece tommorrow. :)=20 In returning a bit to the starting point for this thread, it seems we = have reached a consensus that this problem about keybeds and lost motion = is probably more related to felt being affected by humidity changes then = to wood related concerns ??=20 =20 =20 Farrell wrote:=20 Your position is consistent with many others. It is likely I who is = hard/thick headed. I just may go out to the shop tomorrow morning and = drill me a hole in some maple and see what happens. Just does not make = sense to me. :-) I'll report back! Terry Farrell=20 Piano Tuning & Service=20 Tampa, Florida=20 mfarrel2@tampabay.rr.com=20 ----- Original Message ----- From: Donald Mannino To: pianotech@ptg.org Sent: Monday, January 01, 2001 10:56 PM Subject: Re: moisture in wool or wood. Terry Farrell wrote:=20 I have heard/read this many times, so I suppose it is true. But, = intuitively, it makes no sense to me. If you drill a hole in a piece of = wood and expose it to high humidity, the wood will swell - and swell = much more across the grain (perpendicular to the grain direction) than = with the grain. So why doesn't the hole tend to close a bit - on the two = sides of the whole where the tangents are parallel to the wood grain. Because the whole piece of wood swells, and the hole becomes = larger along with the piece of wood. As I wrote in my last post, = imagine the plug of wood which used to be in the hole. The hole behaves = the same as the plug of wood that was taken out.=20 Do the hole and rod test. Just pick a small piece of maple or = something, soak it in water for a while, then drill a hole in it with a = spare drill. After drilling, put the drill back in the hole, then dry = the wood in the oven! That drill will be really nasty tight in the = hole! You'll have to soak the wood again to get it out.=20 There are some exceptions to this behavior:=20 1. In some situations the surface fiber swelling in the hole = exceeds the change in shape of the wood. Key balance holes are examples = of this, where high humidity sometimes tightens the fit. The wood = thickness is small, and the wood fibers are large and sometimes made of = more reactive wood.=20 2. Cross-laminated wood is more dimensionally stable, and the = surface fibers will again have more affect on the hole size than the = dimensional changes of the wood. This is what happens in pinblocks.=20 3. If the hole was made by compression of the fibers instead of by = drilling and removing wood (like with a nail) then the grip on the nail = is tighter during humid times. All surface fiber effect, no hole to = swell.=20 Don Mannino RPT=20 =20 --=20 Richard Brekne=20 RPT, N.P.T.F.=20 Bergen, Norway=20 mailto:Richard.Brekne@grieg.uib.no=20 =20 ---------------------- multipart/alternative attachment An HTML attachment was scrubbed... URL: https://www.moypiano.com/ptg/pianotech.php/attachments/5e/f4/2c/64/attachment.htm ---------------------- multipart/alternative attachment--
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