making a SMD 500G shock proof

[Alphatronique]

hi

that largely depend on what you need and reason to potting

ex:  for high G protection you need something like epoxy ,that hard and not deform
       but have matched Thermal expansion of the PCB  and part for avoid stress

       or if you need to protect automotive under the hood stuff ,better to use kind of jelly stuff
       this will better protect from environment and allow much less stress on extreme thermal clycling

MG. chemical made some potting epoxy stuff  and available from mouser
but much better   http://www.keypolymer.com/potting-encapsulating/tough-seal/   but this one have to much  flex for Hight G