I keep answering the same questions over and over about waterproofing also, so here is the basic info you need. Its not as bad as I make it sound
If you plan to fly off water - get some CorrosionX water proofing stuff. They have it at the Ace hardware/lumber yard next door to the hobby shop. It can be found in most Ace hardware stores and many Marine supply stores.
If your not going to fly off water you don't need it. If you are - its essential to protect your rx and speed controller and motor and connectors. Infinitely better than baggies, balloons or rubbers or any other method I have tried.
Get the standard (NOT the heavy duty) Marine or Aviation CorrosionX. I prefer the pump spray bottle and not the aerosol spray can, but either will work. The pump spray is a lot easier and neater because you can take the lid off to poor it into a jar for use. The aerosol can is a lot of trouble to get some into a jar for dunking. You will waist a lot.
This stuff is like medium weight oil - about 20-30 weight or so.
Poor some into a large mouth glass jar or small deep bowl. Make it enough to completely cover the parts. Dunk the rx, speed control and motor into the jar and swish it around so that the stuff penetrates all the nooks and crannies. Take the rx case off, if you can, so the gunk can get to the electronics easily. It needs to contact and coat the electronic circuit boards.
Make sure it gets inside the heat shrink on the speed controller too. Get all the air bubbles out. Also be sure all the connectors get a dose.
Once the part is all coated remove it from the oil - I use long nose pliers - and let most of the stuff drip back into the jar. I then put the parts onto several layers of paper towels and let them drain over night. Turn the stuff a couple of times to try to get as much of the oil to drain out as possible. Wipe the outsides of everything off as best you can with more paper towels. Then wipe it again - then wipe it again - then wipe it again and again etc etc.
Be warned - this stuff stinks some (my wife hates it) and if you get any onto something else you will never get glue or tape or paint to stick to that place again. Its a good idea to wash your hands very very well after using it and before touching anything else. Its persistent stuff!
You may think you have drained the part very very well and then lay it down on your wife's pretty new kitchen table - your doomed because another drop will decide to drain out just then
If you want to use sticky back Velcro on the rx or speed controller, you will need to wipe the outside of the case or shrink tubing down with alcohol to get it as clean as possible or the sticky will never stick. Don't get the alcohol on the electronics as that will remove the waterproofing. It also may kill the circuit.
Sounds like a lot of trouble but it will save you blowing up a speed controller or rx if (when) it gets dunked under water. Believe me - if you fly off water it will end up upside down at some point!
I have deliberately run treated motors and controllers and rx's while they were completely under water. Amazing stuff. The TV commercial shows them treating a TV set then tossing it into a swimming pool and watching TV under water.
I put a lid on the used CorrosionX left in the jar and keep using it till its gone. Keep a lid on it as it stinks and may evaporate over time. If you can get the bottle instead of the can you can poor it back in.
I re-treat my stuff once a year and it is doing great. The only things that it didn't work well on were servos. 1 out of 3 or 4 went bad when treated.
On my Capricorn, its not unusual for the plane to get blown over upside down in the water (its the wind - not dumb thumbs
. More often than not, that same wind will catch it and blow it right side up again. So far, I have been able to wait a few moments and fly off the water again as if nothing had happened. I have had the plane upside down for as long as 15-20 minutes with the receiver, controller and motor completely submerged the entire time. When it flips back upright again - off I go with no issues. I have found that sometimes it doesn't work. If water is touching the pins on the receiver crystal it will de-tune the receiver and it wont work until the water drains off the crystal. If that happens, just remove the crystal and blow on the socket and you good to go again.
I do NOT treat servos as mentioned above. Too many of them die on me. I also do NOT treat my batteries. There is tape covering the electrical contacts on most all battery packs. The CorrosionX causes the tape to stop sticking and uncovers the contacts. Not a good thing.
After a dunking I do NOT use that battery pack again that day. I take it home and put the battery in front of a fan to dry it out as best I can. I leave it there for at least a day before re-charging. So far, after many many dunkings, I have had no battery problems.
Do NOT fly off salt water. It will kill the battery packs in just a few minutes and I don't know how well the CorrosionX would work on protecting the esc's and RX's in salt conditions. They use it for Marine electronics, but they don't normally expect a complete dunking in salt water.
CorrosionX is truly amazing stuff.
P.S. Do NOT be tempted to run your motor while its under water with a prop attached to try to 'motor boat' back to shore. The water has soooo much extra resistance compared to air that the motor will draw huge currents and over load. You will probably kill the controller or battery if you try it.
As always with electrics - the FIRST thing to do if you crash - on water or land - is kill the throttle.