[bondo]

the reason people dont water proof(at any scale) with hot glue is because it's a pian in the *** to remove should you need to repair something.
a coat of hot glue on the underside of the board would throw off the tolerances and a coat on the top....well, it would be ugly.

sure it would protect the board from water but what happens if you blow a fet or decide to go with a hotter motor?

i read above that someone said dielectric grease is expensive???
a large tube is about $9.00 and if you ask around an auto store they can point you in the direction of the gram packs for .97

another idea that i've been throwing around but havnt quite tried yet is liquid mask.
similar to rubber cement but cures better and holds itself when you remove it instead of pulling apart. plus it can be sprayed through an airbrush after reducing it with water.
if anyone has some and tries it, i would suggest atleast 6 coats to ensure a clean pull without leaving any stuck to the board.

i also have plans to build a water proof stencil chassis for trucks.
i have the plans laid out and i'm getting ready to cut it.
the only thing i need for production is someone with a CNC and CAD to bring the tolerances closer together.