epoxy alone

[Farrell]

Correction. My post about this epoxy thing is valid on a clean wood-to-wood joint. Ron has a very valid point here if the separation is along a glue joint. 

Doggone you Ron!

Thanks for setting me right!

Terry Farrell
  
----- Original Message ----- 
From: "Ron Nossaman" <RNossaman@cox.net>
To: <pianotech@ptg.org>
Sent: Saturday, June 08, 2002 9:21 AM
Subject: Re: epoxy alone


> >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
>