epoxy alone

[Ron Nossaman]

>So suppose from now on I just worked epoxy into the crack, pulled the
>top together with big clamps, cleaned away the excess, waited two days
>and took the clamps off.  Would it hold?  Has anyone tried this?  The
>epoxy claims a strength of something like two tons per square inch, so
>it seems like that should be sufficient.
>
>This is especially in my mind because today I tuned a Conn console with
>a separated back, even though it has four bolts going the whole way
>through the back.  The separation is in the middle between two of them.
>There is really no room to put in extra bolts where needed because the
>tuning pins are in the way.  What do you think?
>
>Regards, Clyde

Glyde,
In the case of the Conn, it should be fine because the existing bolts are
holding it from separating more. It would probably be just as fine if you
didn't do anything to it at all. This is likely the case with the Wurlitzer
too. Given a piano where the lags have pulled out and there's a gap all the
way across the top, I wouldn't trust a repair without bolts. Looking down
into these gaps, I usually (not always) see a relatively clean separation
at the glue line with little splintering of the wood. That means you won't
have a wood/epoxy/wood joint when you glue it back up. You'll have a
wood/old glue (that failed)/epoxy/old glue (that failed)/wood joint. Why
wouldn't the old glue that failed the first time not fail again this time,
with an indestructible layer of epoxy hanging on to it like grim death?
Epoxy alone might work, or might not. It might work temporarily or
permanently. It might just barely hold, or be something you couldn't break
if you wanted to. How would you know how well it's working until it fails?
I wouldn't trust it. I am reasonably certain that 4-7 3/8" carriage bolts
won't fail under a load that can be overcome with a couple of C-clamps, and
as long as I am unable to properly clean the old glue from the joint, I
think I'll keep using bolts.
Ron N