separated back

[Farrell]

----- Original Message -----
From: "Clyde Hollinger" <cedel@supernet.com>
To: <pianotech@ptg.org>
Sent: Wednesday, October 11, 2000 6:51 AM
Subject: separated back


> Friends,
>
> Today I am going to look at a piano I might obtain and repair.  It is a
> 1947 Cable console with a separated back, a gap of about 1/2 inch, and
> it has an aluminum plate.  I tuned this piano a couple times 5-6 years
> ago.  Not being very observant, I guess, I didn't notice the separation
> until the third time I went to tune; it had wood veneer glued across the
> top.  If I recall correctly, it's a pretty little thing, a shame to
> discard, but Cable pianos aren't rated very high in my mind.
>
> I've repaired back separations several times, with good success, but
> never one with such a large separation.  What are my chances of pulling
> this gap together without the aluminum plate cracking?  Should I even
> attempt it?  Input appreciated.
>
> Regards,
> Clyde Hollinger, RPT
>
>

Hi Clyde. Below is a post I made two months ago regarding a similar
situation I ran into. It seems reasonable to me to use added caution because
of the aluminum plate. If the plate is still flush with the pinblock, a nice
steady even pull with pipe clamps would presumably work well. This may be
extreme, but if you are still worried, you might use an oak/maple block
between the plate and clamp to widen the clamp/plate contact area, thus
decreasing any tendency to crack the plate. I sure found that ALOT of torque
was needed to bring the plate/pinblock back the last little bit to the
frame.

I HIGHLY recommend West System epoxy, thickened with their #404 Hi-Density
Adhesive Filler for rejoining plate/pinblock/frame. I feel one of the best
reasons to use high quality epoxy rather than titebond is that titebond
works best with tight fitting joints - yours will not be tight - epoxy
REQUIRES that a minimal thin layer of epoxy remain between pieces being
joined - and any bigger gap is just fine.

Also, one thing I noted was that while torqueing down, closing the gap the
first day, I thought I would not be able to totally close the gap. But
leaving the clamps on overnight and inspecting the next day, I found that
the materials had apparently relaxed and the gap closed on its own. My
recommendation for your case would be (and this is practical if you have the
piano at your shop/home) to, for example, close the gap half way the first
day, close it half the remaining gap the next day, close half the remaining
gap the following day (or even wait a few days between adding additional
torque), etc. I should think that way you would almost be guaranteed to have
no problems.

Good luck! Write me with any questions you might have. I had alot of fun
doing mine. Kinda sounded like a BIG bowl of Rice Krispies.

P.S. you might want to check for cracked action brackets. That much movement
can crush action components. My case was OK.

> Terry wrote back in August, 2000 regarding Pinblock/Frame Separation<

Significant interest was generated by my post last week regarding a
pinblock/frame separation of 1/2" on a 1968 45" Baldwin Hamilton console. I
completed the repair today and all went well.

I had dropped the pitch 300 cents in the bass and tenor, and 400 cents in
the treble upon identifying the problem last week. A couple days later, I
use nine pipe clamps to SLOWLY draw the piano together. Even with OOoodles
of torque (or at least as much as I was willing to apply - given all the
snap, crackle, that was going on during the process) applied to the clamps,
there was still a good 1/16" gap along half the piano (and I am talking
MAJOR snap, crackle, pop - and boom - twice I inspected the plate with
flashlight because I thought for sure the plate had CRACKED!). I had
originally intended to use Titebond (thanks for convincing my Ron), but
because of the gap, I went back to my shop and got my West System epoxy and
their hi-density adhesive filler. Drilled eleven (yup, that's right - better
safe than sorry) 3/8" holes for the carriage bolts, let off the clamps a
bit, slopped (neatly of course) in a bunch of peanut-butter-consistency
epoxy, cranked on clamps, tightened bolts, scraped off squeeze-out epoxy,
and told the guy "let's wait a couple days for the epoxy to fully cure and
then we will take off clamps and bring the piano back up to pitch".

I really do not think the eleven bolts were overkill. Eight went into the
eight existing screw holes along the plate top. Upon installing those eight,
I let off the clamps a bit and saw that the plate and pinblock were bowing
out between the bolts in the treble - so in went three more bolts (although
I do know that the epoxy will do all the holding that is necessary)!

So, I went back today, took off clamps, and all looked well. I measured the
pitch of the piano and made a few interesting observations. I am VERY glad I
let the pitch down as much as I did.

BASS (A0 to C3): about 150 cents flat
TENOR (wound bicords - C#3 and D3): 150 cents flat
TENOR (plain strings - D#3 to F#5): 20 cents SHARP (at D#3), falling to 80
cents flat (at F#5)
TREBLE (G5 to A8): about 50 cents flat

So, the lower plain tenor strings with the tuning pins up at the top of the
plate where most plate movement occurred while pulling the piano back
together, went from 300 cents flat to 20 cents sharp. Like I say, glad I let
some tension down!  :-)   Well, today was a good luck day. I wonder what
tomorrow will bring?

Thanks for all the input last week, it really helped me out. Never having
done a big separation like this before, I felt as if I knew what to expect
before I went into it. Great feeling!  ;-)

Terry Farrell
Piano Tuning & Service
Tampa, Florida
mfarrel2@tampabay.rr.com