rib glueing

[Farrell]

A few answers and a few non answers are interspersed below:

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

----- Original Message -----
From: "Garold Beyer" <garbey@wingsisp.com>
To: <pianotech@ptg.org>
Sent: Saturday, January 06, 2001 4:32 PM
Subject: rib glueing


> Anyone,
>  Having taken the plunge to replace soundboards, I need a rib press. The
> traditional go-bar press won't do because of space limitations. Having
> searched the archives and back issues of the Journal I'm thinking of
> building a variation of the pneumatic presses as described by Claire
Davies
> in the 10/87 Journal and David Hughes in 9/93. In the archives I saw
> references to "individual rib clamps" being used by several people on this
> list and would be interested in knowing more specifics. Of course at this
> point I have more questions than I can give thought to but any ideas from
> those that use any space saving but practical and effective methods would
be
> appreciated.

I too am just starting to replace soundboards. The most space saving device
I have figured out is no device. I know everyone has their own way. I
initially thought that I would start with making my own boards.......but
after much contemplation, I have decided to start replacing boards utilizing
the "board in a box" concept. I will be getting my first board from Andre
Bolduc. I have heard nothing but good things regarding Nick Gravagne's
boards. The prices are VERY reasonable, and to start, I figure I'll have
enough on my palate just replacing the darn thing, let alone building a new
board from scratch. Just my thinking.  :-)

>  One question I have concerns clamping pressure. The Davies press gives
> 100PSI which seems excessive compared to the Hughes variant at 35PSI which
> seems more reasonable to me.
>  Another question concerns bottom caul configuration. If one is using
> straight ribs and compression crowning (I am), does pressing into a curved
> surface have any material effect on the crown or is Jack Krefting correct
> when he stated in one of his series of articles that it does not.

I haven't done a board yet, but I have laminated many a compound-curved
rib/frame for a wooden sailboat. If you induce a curve to two thin pieces of
wood and glue them together in the curved state, THEY STAY CURVED. Unless
piano soundboards follow some other natural principals, my guess is that is
DOES matter.

>  Also, I plan on using the individually inflatable system with "Schrader
> valves" as in the Hughes article but must confess these are unfamiliar to
me
> and I need to know where to obtain them and also what sort of supplier I
can
> try to locally get 1 1/4" mill hose.

Industrial hose supply. Ask a firefighter where they get their hoses. Open
Yellow Pages and look under hoses.

>  I guess you can see that this whole project is in the very elementary
stage
> so any direction you experienced soundboard installers that use similar
> systems can point me in can help me immensely.

I have made the mistake before of taking on too much new all at once.
Consider the "board in a box" approach.

> Thanks much,
> Garold Beyer
>
>