A nice suprise fix

[Joe & Penny Goss]

Richard,
I am not quite sure what you are trying to say that you did!
Was it the expantion of the epoxy in the ribs that gave more crown?
If so a very interesting consept. To drill holes along the ribs to gain more
crown.
Joe Goss
----- Original Message -----
From: Richard Brekne <richardb@c2i.net>
To: <pianotech@ptg.org>
Sent: Sunday, December 26, 1999 3:03 AM
Subject: A nice suprise fix


> List:
>
> I thought I'd put this in the mix just for kicks and any comment
>
> I just "fixed" up an old german make (Krautzer or something like that, I
can get
> you the correct name and number if you like). This is typically the kind
of piano
> I just throw away, as its condition was just absolutely horrible. But
> circumstances surrounding the ownership and some close personal
relationships
> convinced me to "paste" this thing back together. It is used in a home for
the
> retarded that has no chance of buying anything else, or even paying for
the
> repair..
>
> The soundboard was extremely cracked up, ribs mostly pulled away, and this
> horrendous warpage along one side of the worst crack. In addition someone
at
> sometime had tried to repair this board by screwing (countem) 149 screws
through
> the soundboard and into the ribs. Needless to say this was a miserable
failure.
> There was no downbearing anywhere along either bridge, and the board had
no crown
> left (perhaps even a bit of negative crown in the lower tenor area, hard
to tell
> because of the condition of the board)
>
> Anyways... I told these folks what I think of such pianos, and that all I
would
> do was to reattach the ribs, and fill the cracks with epoxy to stop all
the
> buzzing /distortion, but that they should not expect any kind of good
quality
> sound. It would be made functional and nothing more.
>
> I pulled the plate and removed all the strings, bored through the panel on
each
> side of all cracks along the ribs and  forced the board back together
glueing
> with epoxy (west system epoxy). Along the crack that was curled badly, the
panel
> just cracked up some more, so those and all other cracks were filled with
the
> same epoxy.
>
> The interesting part tho has to do with how I reattached the ribs. There
was
> little holding any of them in place. I started at the top (treble) side of
each
> rib, wedged the panel slightly outwards before tightening the bolts and
glueing,
> then moved basswards. I noticed almost immediatly that each rib was being
> "pulled" a bit towards the treble side. Each of the 149 screw holes were
filled
> with epoxy, and then tight dowels pushed into the holes to force as much
epoxy
> into any hidden loose spots between the ribs and the panel. When I got
done with
> the whole thing the lower end of each rib had moved quite a bit towards
the
> treble. The rib across the bass bridge moved actually about an inch. A
couple
> days of curring and I removed all wedges and measured the crown in the
board.
> Whoooaaa... tons of it. A string across the panel backside showed 2 mm in
the
> middle, and whats more it all looked really evenly graduated where ever I
> stretched a line. After restringing there was just a bit of downbearing
and
> fairly uniform along the whole panel. (the lowest bass and lowest treble
had the
> least bearing, highest treble just a bit more, and the areas inbetween the
most,
> even through the treble / tenor break)
>
> Its up to pitch now, and sounds absolutely great. I couldnt believe the
sound
> actually. pretty clean, not a hint of that "old beat to shi... soundboard"
sound.
> Really strong, especially the bass has that nice big boomy sound.  Nice
crisp
> high end, and no really bad spots or uneven spots anywhere.
>
> I suppose I will have to wait to see how long this pasting will hold up,
but in
> anycase it was the nicest suprise I have had in a long time. It does seem
to
> point at a method of re-introducing crown to an old panel tho, and I got
another
> beater with a particularily nice case that I can experiment on. <grin>
>
> Richard Brekne
> I.C.P.T.G.  N.P.T.F.
> Bergen, Norway
>
>
>
>
>