Rim splitting

[Delwin D Fandrich]

John W. McKone wrote:

> I just got back from looking at a Yamah CFIII that I will be rebuilding
> soon, and found one heck of a rim split.  This is not your typical
> lamination separation that any of us who rebuild see fairly often, but a
> horizontal split completely through the rim, from inside to outside.  The
> split is about a foot long and is located about one inch above the
> soundboard.  It begins on the bass side of the piano, just where the rim
> begins to curve around the back.
> 
> Has anyone had any experience repairing something like this?  

Yes. If possible try to find out why it split. I've done three that
split in a similar manner due to the piano being dropped by movers. This
seems to happen more often in Japanese & Korean pianos because of the
"select hardwood" that are typically used in their rims. It's doubtful
that there would be a structural defect in a piano like this, but check
it out anyway.


> I'm trying to
> decide what glue and/or filler to use to get the best combination of
> stability and structural integrity.  It seems to me that fiberglass might
> be the best bet for gap filling, 

"Fiberglass" may fill the gap, but it's a lousy adhesive. Use a good
quality, reasonably fresh epoxy designed for wood bonding. Check a
marine supply shop. Geougen (check spelling?) Brothers WEST System epoxy
is one that would be very good for this purpose.

> but may not hold the split as well as something like resorcinal.

Resorcinal is an excellent adhesive if the glue line is very thin. It is
a very poor gap filler.
 
> Ideas? Comments?

Assuming that you use epoxy, you will have to be certain that you fully
saturate the crack. This means that you will have to figure out some
method of injecting epoxy fully into the cracked area. If you aren't
able to do this, you may have to open the crack up further.

I'll leave it to others to deal with repairing the polyester finish
after you're through. 

Call if you want to discuss this further. I'm in the directory.

ddf