Potting Compound?

[Yankee]

Hello All,

I have found the info on this forum to be very helpful (thank you)
Built my first lipo charger the other day and appears to work very good.

I have a couple questions for the electronics wizards that are on this forum ;)
concerning "waterproofing" receivers and speed controls for marine use.
I heard of this stuff called potting compound that appears to be a type of epoxy resin to "coat" the circuit board and surface mount components. But its kind of pricey and hard to get (Living in Australia).
My question isd this: Could you use just plain old generic epoxy resin?
Does this potting compound have special electrical properties that plain old resin? Is there a way of testing my epoxy on something as a test without ruining my electronics in the process. Such as checking resistance across some cured epoxy. or is the difference purely chemical (non-corrosive)?

Any help in this matter will be greatly appreciated
Cheers
Yankee in "oz"

[Mr.RC-CAM]

Rather than pot the electronics, try using a conformal coating. This brush-on material is usually clear and later on board repairs are often still possble. Your local electronics distributor should be able to get this for you. Like potting resins, it is not cheap.

In my opinion, a better method might be to use rubber latex gloves as sort of a R/C waterproof bag. Just wire-tie off the ends, maintaining tight seals around wires and such. This method allows repairs to R/C gear when it needs it.

RC-CAM

[Zlatko]

Hi Yankee (in OZ), :)
I, like, Mr. RC-CAM have used latex gloves ( fingers ). I haven't tried this but you should be able to use non lubricated condoms too :) .
I have put silicone/silastic ( neutral cure ) around the servo/power wires and then put the streched finger over the RX. Then, used a rubber band to go over the wires,silicon and the latex finger.
The whole setup was water proof and the silastic can be removed reasonably easy in the future. Potting mix is kind of "permanent" :) .

Good luck and welcome to RCGroups

[jeffs555]

If you use silicone/silastic(usually called RTV over here) anywhere near electronics, make sure you get a neutral cure version like Zlatko said. Unless it is labled non-corrosive or neutral cure, it will have acids in it which will corrode electronic circuits. There is no way you can really test a compound to see if it is safe for electronics, because corrosion problems might take months or years to show up. I also agree that it would be much better to use a non-permanent method to waterproof your electronics.

[AndyKunz]

I use 3M's DP270 Clear on the racing marine controllers I manufacture (RC-Hydros.com). One of my dealers is located in Oz - www.fastelectrics.com - and he should be able to vouch for them.

It is perfectly clear, cures hard, and can easily be removed (with 700 degree iron, fine tip) to fix if ever necessary.

Andy

[Yankee]

Thank you all for your replys
Cheers Yankee