Rim Width

Ron Nossaman RNossaman@cox.net
Sat, 07 Sep 2002 09:55:57 -0500


>Roger, Roger, you flatter me to the point of sillyness! I appreciate your 
>input, but no one has entrusted me to put my first soundboard into their 
>S&S D!

I don't know, Terry. Doesn't seem that flattering to me to have someone 
suggest I might know where a S&S D is and can go measure it. Heck, I've 
actually even gotten in my truck and driven a couple of miles to get that 
sort of information. But I'm a hard head, so I suppose that's understandable.



>My first board will go in a no-name micro-grand. However, I have the need 
>to make up a set of clamping cauls and I wish for them to work on any grand.

An interesting assumption. Based on what, I wonder. What would make the S&S 
D the universal template?


>  if I remember correctly (I have not seen many pianos with the boards 
> out!) the width of the soundboard/rim contact area is most often not the 
> full width of the inner rim.

Often not.


>  My concern is that if I make my cauls out of 1.5-inch thick lumber and 
> make the bottom edge at a one degree angle (I'll have to check and see 
> what angle most rims are beveled at - but I think it is close to one 
> degree) to meet the rim bevel, I might be stressing the highly-crowned 
> board a bit. Perhaps a one or two degree difference between board angle 
> and caul bottom angle is just a not a concern.

Except for not getting a decent glue joint if you can't force the board to 
the bevel. I think it's important to glue a panel down solidly.


>Any opinions?
>Terry Farrell

Yes. The easiest way around this, with stone age tooling, that I've ever 
come across is an idea I cheerfully stole from Shawn Hoar. I go to my local 
lumberyard, find a sheet of 3/4" plywood that was on the outside of the 
bundle and has forklift tracks, scratches, nicks, dings, and strapping 
marks all over one side. Pointing out that they can either throw it away, 
or sell it to the only guy likely to come along who is willing to buy it 
for half price, I most often take home a $10 sheet of nice plywood that's 
clean on one side. From that, I cut and piece together a full perimeter 
caul matching the inner rim width all around. When the soundboard goes in, 
that caul (clean side down) distributes clamp pressure so I don't mark up 
the panel with my clamping blocks, which are made from 3/4+" scrap lumber. 
Even while distributing clamping pressure, the caul is flexible enough 
to  conform to any rim bevel I've run across, or produced, so I know the 
panel is clamped to the rim across the full width of the rim. Very low 
tech, and more effective than anything else I've tried. While I do waste a 
sheet of plywood every other piano, it's something that someone else has 
already rendered into trash by poor handling, so I consider it salvage more 
than waste. I like this method a lot, though I'd certainly be interested in 
hearing better ideas.

Ron N



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