The first link broke but I saw the second. Looks cool - thanks for sharing
Well... it is not so much the cost anymore. We already have enough epoxy to cover the statue of liberty - the problem is really getting the viscosity right so that it is thin enough to release the bubbles but thick enough not to run into the connectors. A huge part of the problem was working around the JST's - but since the next batch of boards wont have parts on the JST side we may consider trying Epoxy again.
Anyway - the trouble is that it is hard to make a mold that will allow us to do 8 boards at a time. With the silicone I just clean the boards well in the ultrasonic (with Iso) then clean them again with 99%, then compressed air - then I just blast them with the spray on coating 8 at a time and set them in my little heater curing box to speed things up. With the epoxy we really need to break them up into individual boards and do them one at a time. It turns into a race to beat the 5min epoxy or a waiting game for the 30min to cure.
I love epoxy actually - I just have not figured out how to use it wisely.
I invested pretty heavily in the gear to make silicone molds. This is an AWESOME platinum cure silicone that sets up in only an hour and requires no de-gassing. I suppose we could make a monster-mold that does a sheet of 8 boards at a time. We could then run a thicker epoxy (so it does not sneak down and around) and mask the micro-bubbles by adding a pigment. Vacuum wont work because it sucks the epoxy into the JST connectors.
But... even if that works we are still left with the other side of the board. On that side electrolysis can still attack the via's. I left this batch of via's tented - which will really help combat conductivity between points - but none the less it needs to be insulated in some way. I suppose we could paint a thin coating of epoxy on that since there are connectors but no parts.
Anyway - thanks for the help! I will check that Tek out.