Soundboard to Rim Clamping Pressure

Ron Nossaman RNossaman@cox.net
Wed, 11 Sep 2002 15:43:18 -0500


>I have read a fair bit from various sources regarding the importance of 
>proper rib-to-panel clamping pressure. Most recommendations range from 40 
>psi to 100 psi. Other recommendations for softwood glue joints from 
>woodworking sources (like Franklin) suggest softwoods require closer to 
>100 to 150 psi. Franklin also recommends higher pressures for hardwood 
>joints. OK.
>
>I have not come across any definitive recommendations for 
>soundboard-to-rim clamping pressure, save for "not too little and not too 
>much - go for good squeeze-out". This seems a bit nebulous to me. Anyone 
>able to be more specific? Perhaps more pressure is required as we have a 
>hardwood-to-softwood joint there. I would hate to see one of my boards pop 
>out after a few years.
>
>Thanks.
>
>Terry Farrell

Use an adequate amount of glue. Clamp the joint together until it gets 
solid. Don't crush the piano with the clamps. Mop up before the glue dries. 
Come back tomorrow and put the clamps away. Sure, it's scary, but trust 
what you know and pay attention, and it will be fine. If that doesn't get 
it for you, go here http://www.ukuleles.com/Technology/bridgeglue.html and 
learn how to produce the exact clamping pressure you want with any kind of 
screw clamp you may have. Just don't get so wrapped up in the minutiae that 
you forget the basic design.

Ron N


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