[CAUT] Soundboard mass

[Ron Nossaman]

> OK, so you've discovered via vice grips clamped to rear bridge pins that the
> top couple octaves would benefit from some added mass. Problem is that the
> top octave of the board is above the belly rail. There's no more than a
> quarter inch of clearance in this region between the top of the belly rail
> and the bottom of the ribs.
> 
> Solution: drill a hole through the keybed, up through the belly rail. Hang a
> brass weight. I'm thinking that I'll need to drill maybe a 1.25" (or maybe
> 1.375") hole to allow some clearance for my 1.125" diameter brass stock as
> it will be hanging down into the belly rail.  I don't know yet how much mass
> will be effective, but I'm thinking that I'll try at least 100g to begin
> with. This is a M&H BB with adequate sustain but the weight of the vice
> grips added some body and carry to that sustain.
> 
> Anyone ever done this? Seems I remember Ron N doing something like this.
> 
> Thanks for your thoughts and experience.
> 
> Alan

Hi Alan,
When I install a board, before I glue it in, I locate and 
drill 5/8" holes through the belly rail and key bed, directly 
under where each screw and button is. The weights (1-1/8" 
dia.) slide onto the top of the belly rail from the back side, 
and are  centered over the hole and speared through the key 
bed and belly rail with the drywall screw taped to the long 
screwdriver. No need to make the holes big enough for passing 
brass. <G> I typically use a couple of 60g weights in two 
places, rather than one big 100g+. Usually one at the top end, 
and another either the next, or third button down.
Ron N