loose pedal lyres

[Keith Roberts]

The main complaint about CA glues is they seem to have a life span of 3 to 5
years. Actually what happens is they get brittle. A tap with a hammer or
drop it lightly and the glue turns like a tempered glass window. Dust.  This
is why it is not recommended to use CA glue to fill or span gaps. The least
gap, the least amount of glue = the stronger joint, the longest life span.

Keith R



----- Original Message -----
From: "Dave Nereson" <dnereson@dimensional.com>
To: <pianotech@ptg.org>
Sent: Monday, February 18, 2002 11:56 PM
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
>
>