.....yes, you can, provided you use Araldite slow setting epoxy (the
blue kind).
don't forget that the FR4 board is made of it!
while working at Tadiran, years ago, we found out that the slower the
epoxy cure the better its RF characteristics.
we never found out why- actually we never tried hard enough- but the
fact remains.
on higher frequencies you have to be careful, but Bluetooth thrives on
FR4 (at 2.4GHz)!.
Saandy 4Z5KS