The term is elastomer.   I would expect a substantial damping effect from
encapsulating the bolt in RTV.  One thing to worry about is totally

filling the

cavity.  RTV has a VERY high CTE and in a fully trapped (and sealed)
application can generate EXTREMELY high, essentially unlimited forces
when heated.   I have seen a 2" thick 12" diameter flat steel lid

attached to a

thick walled 12" steel tube with eight 1" studs deform enough to let the

cured

RTV dribble out when heated to 350F.   Leave a bit of air space or it

WILL

make room.

If the bolt problem is guitar string type of vibrations (lateral
vibrations), then
providing an elastomeric doughnut (sleeve, tube, whatever) in the middle
which is snug on the bolt and in the hole will dramatically detune the

system

and provide substantial damping.  Both are good.

If the bolt hole size is consistent, I'd use a sleeve in the middle

portion.

Sounds
like what the 20B has.  It needs to be a snug fit in the hole, does not

need

to cover the whole bolt, does need to be in the middle, at least

approximately.

Bill Freeman

Bill,
Dave Emanual and Jim Downing of "How to Modify your RX7 " agree with you
on this - Page 102 has good photos and installation  instructions. Page 103
advises to put rubber hose  on external bolts for the same reason ie.
vibration control.
George (down under)

 
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