This is a multi-part message in MIME format. ---------------------- multipart/alternative attachment Hi Jon. I am interested in the pic of your tool. St=E9phane Collin. ----- Original Message -----=20 From: Jon Page=20 To: Pianotech=20 Sent: Wednesday, December 18, 2002 1:18 PM Subject: Re: Bridgetop Extravaganza Revisited I wouldn't trust a shallow fill of epoxy to resurface the cap, recap. As far as pounding the string, I agree that it is over-rated and have tapped the bridge pins as Roger Jolly suggested to relieve false = beats. I also devised a tool for removing the natural curve from the wire at = the pins to improve the termination. I posted to the list a few years ago about = it, I have a jpg file if any one is interested in viewing it.=20 Regards, Jon Page At 02:13 AM 12/18/2002 -0800, you wrote: Hi All, =20 Just joined, first post to this or any other group. Serendipitous = timing, just read all the recent bridgetop/ bridgepin posts. Have a = 1985 Stwy D in the shop for action overhaul and restring. I thought I = was noticeing something funny about the bridges but was in denial until = I started taking all the teardown notes. The plain wire strings have = been pounded (seated) into the bridge so that at the edges there is more = wire diameter below the bridge top than above it. When viewed from the = side the wire makes a pronounced curve up onto the bridge and down again = out the rear making accurate component readings impossible to do from on = top of the wire. It was showing negative front bearing until I realized = what was happening and started using the actual bridgetop as reference. = Situation is most severe at capo sections and diminishes down to what = looks like normal grooves to me under the bass strings. Deflection in = strung piano is .5 deg at bottom of low capo, 1-1.5 deg rest of capo = sweeping up to 2.5 deg at note 88. There is .250" crown at low capo. = (measured from top of board) =20 Is it possible this condition is due to the quality of the = capping material? I usually work on much older instruments. I have = never seen string cuts like this. Also the various pressures have = caused dead wood to swell up and check here and there around the = terminations. Again I'm not used to seeing this. Inspection of the = pins under magnification shows the string resided in two distinct = locations. My theory: Pre- and Post Pounding. There are also a lot = of unexplainable nicks on the side of the pins. The pins pull out = easily. No cracks to speak of. This is an institutional piano which = has probably been in Southern California its whole life. What I'm thinking about doing is similar to what Dale Erwin just = posted. I've never done the epoxy bridge thing but I'm familiar with = the nasty stuff. I'm imagining thickening it enough with colloidal = silica so it won't run down the notches or too much into the holes and = applying it with a small spatula. I want to fill those deep grooves (at = least on the speaking side) and then sand the top flat. If I put the = stuff on in the morning can I pare/renotch and redrill at the end of the = day before it gets too hard and while I can still find the original = holes?=20 Looking forward to peoples responses. =20 I want to stop using the misnomer "string seating" in favor of = wire straightening (or something similar) which is what I do at a low = lateral angle (around the bridges anyway). I have never been convinced = of the need of downward tapping pressure at the bridges. For some = reason this is one of the first things new technicians are taught and = the thought of them going around with little hammers and pounding on = pianos scares me. We straighten wire for control of damper and hammer = contact and for quick stabilization of new strings. Perhaps having the = wire come straight out of the bridge helps the string to vibrate in a = more perpendicular plane even. I don't really know. After you take a = few pianos apart you find that even in a negative bearing situation the = angled pins hold the string tight to the bridge. If there is so much = negative bearing that they don't then no amount of pounding will hold = them there. But I guess that is another thread. Right now I need help = getting out of this mess. I have finally accepted I have to pull the = plate. So much for the quick restring of a fairly new instrument. =20 =20 Thanks, Steve Bellieu ---------------------- multipart/alternative attachment An HTML attachment was scrubbed... URL: https://www.moypiano.com/ptg/pianotech.php/attachments/45/c3/d3/44/attachment.htm ---------------------- multipart/alternative attachment--
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