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post #14 of Old 12-03-2010
Join Date: Nov 2010
Location: Anacortes, WA
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Here's the PCB

Here's the mold

And yes, we just pour the mold full once the PC board has been screwed down in there. To hurry things along we cook it at 120 deg. for about an hour or so. Then, pull out the screws, pop out the part, trim, clean add stickers. Vola! There you go. A waterproof electronic thingy.

Our resin currently comes from : EFI polymers

Our contact for the epoxy rep. : Potting solutions
Jim Halstrom (303) 617-3094

Resin : 20203-5
Hardener : 50015

These are for roughly 5 gallon amounts. I don't know how small they will go. Your cured resin will be on the order of $5.25 / lb.

Thermal properties:

Some resins are better than others. We used to use an epoxy from Dolphs, it had better heat sinking than what we are using today, I'm not really sure how much better. Dolphs is harder to come by on the west coast so we switched. One trick is to bolt down a heat sink plate to the mold along with the connections. This way you can have the heat wicked out if that becomes an issue.

Our stuff, seeing its for people sitting an anchor, is -really- low power and we do every thing possible not to waste any in heat. (Notice the power supply? Digital not analog, doesn't get hot.) Meaning, there is very little heat to wick out, so its never a problem. My brother on the other hand designed stuff for driving small to very large electric motors. Heat was always an issue. Designing for external heat sinks, extra large power hookups that doubled as heat sinks, etc. etc. There's a million ways to deal with it.

So that's everything I know. Hope it helps!

-jim lee

Builders of marine Stereos, LED lights, Sailboats and whatever else looks fun.
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