Waterproofing foam planes

[quarry44]

Since I have my Canadair waterplane pretty much assembled,it reminded me that electrics and water are not a good combination
I'm going to have to protect the esc's etc.,as I know from previous experience with floatplanes,no matter how careful you are,water will find it's way in.
I used to put my rx and battery pack in a balloon,and that seemed to work reasonably well.
However,with electric power there is also heat dissipation required,so the balloon doesn't seem such a good idea.In any case,most cables come out either end,so a balloon is again pretty useless.
I've read on RC groups about some stuff called "conformal coating".Does anyone have any practical experience with this stuff,and can it be bought in a small quantity?I don't want to be spending $100 upwards,as most of this stuff seems to cost.If I coat the electrics,will heat be an issue?
Is CRC 2049 a good alternative?I can get that in a spraycan for about $22 nz.
Does anyone have any other stuff they use to protect their esc's,ubec's,etc.?
I'll be giving the canadair a good wringout on land before I go anywhere near a puddle,but it's as well to be prepared.

[RCModelReviews]

Good questions but no answers.

I'd just avoid crashing into the water if it was me.

Electronics such as ESCs shouldn't mind *fresh* water too much - but salt water will kill most electronics.

Another option is a very light coat of clear polyurethene spray - it's waterproof, light and shouldn't affect any of the electronics. Because it dries pretty quickly it's also not likely to react with the plastics or wick into any of the components and cause issues.

[quarry44]

I'd just avoid crashing into the water if it was me.

I have no intention of crashing,Bruce
I was thinking more of stray water seeking out any possible entry into the electronics.1 esc giving up the ghost could be a bit of a nuisance on a twin.
I,ve also been reminded that spray rails at the bottom corners of the hull are a good idea.I'll certainly be fitting some on the canadair.
I was considering some stuff called "Plastidip".It's a rubbery substance used to coat tool handles ,etc.It's a mite expensive though,$40 for a little bottle at mitre10mega.
The polyurethane would be a lot cheaper.I might just go ahead and buy a can of that.

[cynr100]

Have you tried Lanoguard, it provides a non-conductive, non-corrosive waterproof seal. We use it at work (sewage treatment) to provide short term proofing, anything from boot leather to hand held electronic field measuring devices.
Does get messy with continued use put has protected some expensive equipment.

[kaptain_zero]

Unless you are flying over salt water, as Bruce said... I wouldn't worry. I've seen upside-down landed planes that would still paddle their way back to shore using the electric motor.

Salt water is an entirely different issue... If I had to fly over salt water, I'd just use the cheapest electronics I could trust and write them off if they get a dunking. Plastic bags are the easiest way to protect electronics, add some electrical tape to seal the wire openings and you're off to the races. Any coating will insulate and cause retention of heat. Silicone grease repels water very efficiently and is a dielectric (we used to fill spark plug caps with silicone grease on motocross bikes so they wouldn't short out in the water). Silicone sealant could also be used to seal openings but beware of the type... Typical draft sealants at your local building supply outfit will release acetic acid while curing which would be fine for foam, bad for metal connectors/wires/circuit boards. RTV silicone sealants (used in electronics) contain solvents and would be bad for foam but safe on electronics/metals.

Conformal coatings info: http://goo.gl/cRxeW

Source for conformal coatings: http://goo.gl/TzPGq

My choice, seal the areas that contain electronics, use cheap electronics and keep your fingers crossed. Spending hours and big money trying to save cheap electronics is NOT the best solution IMHO.

Regards

Christian