I have one tidbit for you. You said: > With some Asian pianos, loose lyre parts produce "polyester squeak", > where two polished surfaces squeak against each other. I've tried to > chisel, sand, scrape the polyester away so I can glue bare wood to bare > wood, but polyester and any type of glue, for that matter, really soaks into > the grain and makes the wood more like a hard plastic. At least in relation to what kind of glue sticks to polyester: epoxy. Make sure the mating surfaces are roughed up (maximum adhesion can be gained by actually sanding some unthickened epoxy into the surfaces - although I only do this in super-critical applications - but maybe the strain on a lyre would warrent this?). Wet surfaces with unthickened epoxy, fill gap with epoxy thickened with high-strength, gap filling filler. I'm not saying I recommend an epoxy repair over your traditional approach, but in the case where you are looking for an adhesive that sticks to polyester, epoxy is your magic solution. I always use West System products: http://www.westsystem.com/ Great web site with lots of technical advice. Terry Farrell ----- Original Message ----- From: "Dave Nereson" <dnereson@dimensional.com> To: <pianotech@ptg.org> Sent: Tuesday, February 19, 2002 2:56 AM Subject: loose pedal lyres > What do you guys and gals do with loose pedal boxes, besides > putting a book underneath (just kidding)? I've always taken the lyre to the > shop, drilled out the wedges (much drilling with different size bits at > various angles, followed by careful chiseling and gouging) until it will > knock apart with a rubber mallet, then sand, chisel, scrape off as much old > glue as possible to get maximum bare wood exposure (but trying not to reduce > the dimensions of the tenons or expand the holes too much), then glue the > whole thing together and insert new hardwood wedges (which I usually have to > make myself, axe and hammer handle wedges being too small -- does anybody > sell bags of pre-cut wedges for piano lyres?), then clamp the whole assembly > overnight, then the next day, trim the ends of the wedges, clean up and do > minor touch-up -- quite time consuming. One tech I know doesn't > bother -- he just CA-glues the heck out of it and says he's never had a > problem, but I don't trust it to last over the years. If you do it the > long way, do you pound the wedges in while you're glueing the posts to the > top block and pedal box, or do you wait until the assembly has dried, then > pound the wedges in last? > With some Asian pianos, loose lyre parts produce "polyester squeak", > where two polished surfaces squeak against each other. I've tried to > chisel, sand, scrape the polyester away so I can glue bare wood to bare > wood, but polyester and any type of glue, for that matter, really soaks into > the grain and makes the wood more like a hard plastic. The pedal box > sometimes isn't entirely of wood -- there can be a plastic insert (mortise) > where the tenon enters the pedal box but you can't see it because the > polyester finish hides it. It doesn't chisel, sand, or scrape without > chipping or breaking or sending a crack across the whole top of the pedal > box. I guess CA would work here, but does it hold? Will it last? > > --David Nereson, RPT, Denver > >
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