On Aug 20, 2009, at 9:27 AM, reggaepass at aol.com wrote: > When spacing (i. e., bending) the portion of the key between the > balance pin and the distal end (where the lifter felt is) is > indicated, does anyone have a technique that works particularly well > for them? We are experimenting with heat alone (which we have found > to be extremely slow-going, so far) and with steam (more rapid > results, but harder to contain than heat without all that moisture > in it). Thoughts? > > Alan Eder I'll try to find time to take and post some photos tomorrow. Meanwhile, my method involves getting the key wet, and clamping it in the alignment I want. First, about wet: when we want to do a severe and permanent bend to wood, like a harpsichord bridge, we actually immerse it in water for many hours. And then put it in a jig the shape we want. Works quite well. With that in mind, I get the side of the key (side meaning front or back here) I want to bend quite wet, brushing on enough water to have it standing on that side of the key, and let it soak in. And turn the key and do the same to the other sides. And do it some more. Keeping water away from where there are glue joints and whatnot (capstans, buttons, etc). I have a jig I made that I clamp the key to (photos will make it easier, but I haven't taken them yet). I clamp so as to hold the area around the balance hole firmly between two pieces of wood, spanning well beyond the area the has been routed away inside (avoids key breakage, and that area is the one we want to use as the point of reference anyway). When I first did this, I used a piece of 2x4, and used a pair of hand screw clamps to clamp the key to it, with a spacer between the key and the 2x4 (a bit of 1x4 or something). With the key well clamped, I then come up with a way to bend it as needed, whether a straight bend or a twist, using a clamp or two to hold it in position. For a twist, I use a wedge or two under the key. For straight, I just pull or push the key straight in the right direction. I measure before applying any clamping, to see where I was to start with. I then clamp in the direction(s) I want, adding pressure until it is well over twice as far as I want it to be. I then apply heat from a heat gun, running on both sides back and forth until it is pretty dry. Let it sit until cool. Unclamp and measure. If it didn't go far enough, repeat with more water and farther clamping movement. I have been able to deal with whatever I have come across since I came up with this system. In the case of university instruments, I have been back to check, and they have essentially stayed put (maybe moved back to some extent, but not enough for problems). I made an actual jig that makes the job far more convenient, along with an assortment of wedges of different angles and other shims. Regards, Fred Sturm University of New Mexico fssturm at unm.edu
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