 Under the waterproofing your electronics I mentioned that the hands down best solution is to use a conformal coating (3M DP-270 clear) since it completely seals the part preventing any water from reaching the your electronics from the elements. In this section I will describe you how to do it. 
The first step is to select what you want to coat, for this topic I chose one of my radio receivers. I started by removing the radios circuit board from the plastic enclosure. Next make sure all the contacts you normally use are covered with a plug or tape. For a receiver these are the pins where you would attach your servos and battery. When doing this I cover approximately 3/4 the length of each pin so I can still get epoxy around the base to ensure a waterproof seal. If you do get epoxy on the pins you can just scrap if off with an exacto when it hardens. 
Note that when coating your equipment you want to make sure not to cover heat sinks or the metal tabs of your ESC Fets. This is because the covering is also and excellent thermal insulator, so leave the parts that need to be cooled uncovered and exposed to air.
Next up is to mix your batch of epoxy, its like any other two part epoxy that requires equal parts of hardener and epoxy. You will have ample working time with this material so don't rush. For each Rx I dispensed about a 1.25" diameter blob from each tube. Mix the two parts thoroughly and get ready to get your fingers sticky. 
To start I like to place the part in a clean mixing cup and transfer the mixed material onto the part. I just scoop up some epoxy with my mixing stick and apply it onto the Rx. You will need to use a small stick, like a toothpick, to work the material down into all the nooks and crannies you can see. Now flip the part over and repeat. I also like to pour the material from one side and have it flow down the part and drip off into my mixing cup. I do this from each side. The point is to cover everything and get the epoxy all over, around and under everything. When you are satisfied its been covered then let it hang to dry. 
When the epoxy has hardened you can usually fit the part back into its original case, you might have to do some minimal trimming of the epoxy to get it to fit, however don't remove so much that you expose the part forcing you to do some small touchup. If you are uncomfortable, or don't care to do this, then just cover the part in some shrink wrap so you have a surface to mount the part into the hull. | 
