Overs laminated soundboard

[Phillip Ford]

There was some list discussion about sound board presses recently. I
got the first image of my vacuum sound board laminating press
prepared for the web site yesterday. The image below shows the press,
with a test strip of sound board panel and one rib being pressed.

http://overspianos.com.au/vacpress.jpg

I haven't written a text page for the image yet. The press is 6' x 8'
(1800mm x 2400 mm). The vacuum pump is a Becker 3ph 2 hp unit.

A cutaway of the pump can be seen at;

http://www.becker-international.com/en_z010.html

It can pump 28 cfm when unrestricted and the vacuum can be adjusted
from 1.5 psi to 12 psi. (12 psi will yield a hold-down pressure of
around 0.75 tons/square foot - or 0.8 atmospheres). We use the
minimum 1.5 psi vacuum for gluing the panel to the ribs. The vacuum
diaphragm is a fibreglass reinforced vinyl, fitted to a lightweight
RHS frame which can be lifted on and off the table with ease. The
vacuum is delivered from the pump to the the table using the RHS
frame as a vacuum plenum. A series of holes on the inner edge of the
RHS allow the air to be evacuated from around the perimeter of the
table. Apart from its use as a sound board assembly table, the press
is also very useful for gluing veneer to panels. We will also use it
for the manufacture of the laminated sound board panels which we are
using for our own piano. By the way, the poser in the image is my
Rottweiler 'Harry'. He likes to fossick around the workshop chewing
the odd sound board off-cut.

Best,
Ron O.
-- 

Ron,

I also meant to comment on this and got this out of the archives as 
well.  At some point you mentioned, either on this list or to me 
personally, that you were still undecided about whether to use solid 
boards or laminated boards in your pianos and that you were going to 
do some further experimentation.  Since you mention the vacuum press 
for making laminated soundboards can I assume you've decided that 
laminated soundboards are superior to solid boards for giving the 
results that you want?

Phil Ford