A nice suprise fix

[Richard Brekne]

Grin

I thought I probably had written so quickly that there would be some
misunderstanding.

What I did exactly was this..

I started at the treble side of the soundboard wedged out the soundboard and
drilled holes through the soundboard and ribs and inserted bolts to be able to
pull the soundboard and ribs tight together again. I then tightened each of
these bolts (without epoxy). I wanted to pull the whole board in and let it rest
for a couple days before doing anything else. I did this to each rib before
moving to the next position basswards. After getting to the center of the panel
I noticed that the ribs were being pulled towards the treble end.

There was almost nothing left of the origional glue holding the ribs in place
you see, so as I wedged out the board (using wedges between the ribs and
backposts) in each new position, the rib was able to give a bit along its glue
line. Drilling, and bolting tight held them in place. By the time I got all the
way over to the bass end of the board, the ends of the ribs had moved quite
signifigantly. The board  was pushed out quite a bit with all the wedging, the
holes drilled and bolted after wedging you see.... from right to left side one
after the other... if you get my meaning.

None of this would have worked had the ribs not been able to move due to the
lack of remaining old glue.

After a couple days I repeated the same sequence to apply the epoxy between the
ribs and board. Started on the treble end, loosened the bolts, worked epoxy
between the ribs and board, tightened the bolts, and moved basswards to repeat
the process. This kept things as they were.

The next day I removed these bolts and started drilling out the 149 screw holes
that had been there from an earlier "repair".  All of these had been along rib
lines and pretty much covered the lenght of all ribs. So I drilled in far enough
on each of these that I could use a 6mm dowel to force the epoxy (thin stuff..
west system) into every possible nick and cranny. I just filled up the holes and
slowly forced the dowels into the holes. The stuff ozzed out on each side of the
ribs in several places. But in the end all holes were filled and all that
remained was to let it dry, and sand down the dowels and board and give it a
quick coat of lack.

Having done that, I finnally got to remove the wedging, and thats where I really
got suprised, tho now that I think about it all it shouldnt have suprised me at
all. There was all kinds of crown. How strong and durable this crown is remains
to be seen of course.

One could work up a job routine to do all this on purpose in cases with little
or no remaining crown, by simply securing the treble end of each rib with
bolts.. and then loosining the rest of each rib so they are free to move along
their glue lines as you force the board out in the above described fashion.

Grin.. Hope this is easier to understand,, tho explanations are definately not
my forte.  If not I will gladly try again in a private note to you.

Richard Brekne
I.C.P.T.G.  N.P.T.F.
Bergen, Norway

Joe & Penny Goss wrote:

> 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
> >
> >
> >
> >
> >