Is it possible to use epoxy or polyester surfboard resin for potting
audio fequency PCB's?
How about the crystal epoxy used for encapsulating insects, etc?
Any other low cost alternatives, aside from flexible rubber/silicone?
Many thanks,
Larry Kent
Don't use general purpose epoxy or polyester! Some formulas will sweat
compounds that are corrosive and conductive. Formulas meant for fiber
composites can get so hot in large volumes that they'll incinerate
themselves.
You can buy electronics potting compounds at online electronics stores.
Conformal coatings can provide water and dirt resistance without making
the circuit impossible to repair. Aerosol cans of pure urethane from a
hardware store seem to work well too. I haven't seen urethane attack
anything yet and adhesion is pretty good.
Avoid 3M Scotch Weld Epoxy Potting Compound because it has extremely
poor adhesion. It forms beads in thin films and it cracks away in thick
films. Either way your project is ruined.