You can prolong the life of electronics in an FPV drone with waterproofing, the most common method is Conformal coating. It helps prevent components from moisture and chemical damage when flying in extreme conditions.
Conformal coating is basically a thin film which conforms to the contours of a PCB and protects the components and solder joints on it.
You don’t actually have to fly in the rain or snow to Conformal coat your drone electronics. Conformal coating is a good practice to protect the quad from humidity and wet grass/leaves that can cause electrical short on exposed solder joints. It will even increase the chance of survival if you crash your quadcopter in the water.
Table of Contents
The Types of Waterproofing
There are two popular solutions to waterproofing drone electronics: silicone and acrylic.
The main advantage with Acrylic is that it’s easily removable. You can burn through the coating simply with your solder iron.
However, for quadcopters or RC models in general, silicone is better as it can withstand higher temperature than acrylic. Many components in a quadcopter can get very hot, for example, the video transmitters, might melt through acrylic coating.
Buying Silicone Conformal Coating
I use MG Chemical Silicone Modified Conformal Coating, you can get it from:
- Amazon: https://amzn.to/3nkSWyb
These exist in two versions: the older version, and the newer “modified version”. They are basically the same stuff, but the “modified version” fluoresce under UV light (ultra-violet, aka black light). It makes it very handy to verify the full coverage of the coating, strongly recommended!

The board on the left is NOT Conformal coated, on the right is coated – you can tell by the glow under UV light
Its available on Amazon around US$20 for a 55ml bottle, which should last years for an ordinary pilot. It has a nail polish type brush attached to the cap for easy application.
Avoid the spray version because it will get everywhere you don’t want it to be. For example, your USB connector and bootloader button, and they might stop working. And it’s difficult to apply it evenly like you can with a brush.
Don’t forget to grab a cheap UV light torch too, these are cheap:
- Amazon: https://amzn.to/3vbOR2b
Finally, I also recommend getting some isopropyl alcohol (rubbing alcohol). It’s for cleaning your electronics before coating, and it’s useful for removing the coat as well.
- Amazon: https://amzn.to/3gBL6yW
Preparation
It’s best to apply Conformal coating on an existing quad, because getting the stuff on solder pads will make soldering much harder. If you want to do this on a new quad, you should first finish building the quad and fly it to make sure all components are working properly. You don’t want to mess with soldering again after applying.
If you are doing this on an existing quad, then you will want to remove all the tapes and heatshrinks that are covering any PCB. Make sure to clean the electronics to remove any dirt before applying Conformal coating. I use an old toothbrush and isopropyl alcohol for that.
Applying Silicone Conformal Coating on PCB
Warning: Do not sniff the stuff as it is carcinogen! It’s important to have good ventilation when applying it.
Brush it on like nail polish. If you are unfamiliar with the procedure, ask your wife/sister/mother :-p
- flight controller: boot button, USB Port, Barometer
- FPV camera: image sensor
- VTX: channel button
- RX: bind button
It takes about half an hour to dry, though I personally would leave it to dry overnight just in case. Normally, one layer is enough, but if you don’t think you have applied enough or missed a few spots, feel free to repeat for another coat for better result.
At the end you should have a nice, even, shiny layer of plastic coating. Even better, use a blacklight (UV torch) to see if you missed anywhere.
How to Remove Silicone Coating?
Say if I covered the solder pads by mistake and I want to remove it, you can use Isopropyl alcohol. The conformal coating can also be burnt away with a hot soldering iron.

Some FC and ESC come with Conformal coating, such as this Kakute F7 AIO. But as you can see, it clearly was the spray stuff, the coat is uneven, and missed quite a few spots.
Just take a cotton bud, dip it in alcohol, and rub it on the PCB where you want the coating to be removed.
It should only take a few rubs to remove a thin layer of coating.
If you want to remove every bit of coating on a PCB, you will have to dip the whole board in alcohol and clean with a toothbrush. The coating will dissolve, and finally let it dry completely.
Pro Tips
To avoid damaging the connectors, you can try plugging in all the connectors before applying coating. This will ensure it doesn’t ruin the contact inside the header/connector.
As mentioned, Silicone coating can be burnt away by soldering iron. Therefore whenever you re-soldered something, you should apply Conformal coating again to the area.
You can try filling the small gaps, e.g. between capacitors and resistors, by blowing the coating with compressed air (not too close or you can make a mess).
Cap Getting Stuck
It’s important to clean the rim of the bottle with paper towel before putting the cap back on after use. Silicone coating works just like glue and the top can get stuck if you close it with some of the stuff left on the rim.
Here are some ideas what to do when you can’t get the top off:
- Slightly heat up the cap with a hair-dryer or heat gun (don’t melt the plastic though!)
- Smack the edge of the top with a butter knife or against the bench, all around the edge to break the hardened coating
What Happens If You Crashed Into Water?
- Take it out the water and remove battery ASAP
- Rinse it with distilled water to remove any mineral, brush with alcohol even better
- Leave it to dry completely, don’t use rice it’s not practical. Better to use a fan, leave it for at least a day
18 comments
Thanks very informative and educational I’m new to the hobby. My one stop information library
Do i have to coat also my caddx vista? or just antenna port and outcoming wiring only? i am not planning fly in rainy days, just in fog , snow and my crash in snow, so not sure about vista now
I juste realized…my coating IS in polyuréthane… Doens’nt do well wirh water i think…
Hey Oscar, thanks for the information. I will be running the vista nebula pro and those things (according to online and forum reviews) generate lots of heat. Have you seen any issues with heat buildup after applying this product?
Thanks,
Phil
just make sure the large chips are not covered with, maybe it’s okay, the heat is mainly originated from those chips. I have not tried it on the Vista though so I can’t comment if it’s going to work 100%.
Hello. I was wondering if anyone’s conformal coated quad motors. Is it ok to do so?
Drone motors are waterproof already. My float plane recovery boat ran one fully submerged.
Is it possible to waterproof Caddx Vista unit?
is it ok to just dip a an esc in the bottle rather than applying with a brush. Id rather not try to pull of the heatsink.
My Kakute f7 has the SD card slot onboard – any tips for getting around that? I don’t ever intend to use an SD with it, so should I just brush the silicon on normally?
if you don’t use it, then just brush over it :)
Great tut! Thanks!
Ive used Si conformal coating a few times with mixed results. One thing that does work for me is brushing on a coating of CorrosionX on all connections (plugs). Its messy, but it still allows the connection. Also I had some problem with my gps module after I coated it (would not lock on). I cleared the coating from the metal spot in the middle of the top (antenna?) and it got a lock after that. Anecdotal, but it worked for me.
I still have a couple of questions that maybe you could help me with:
1) Do esc require additional protection? That seems to be a particularly water sensitive component and the only thing that smoked after water exposure.
2) What can you do for barometers? Anything?
3) Any tips for coating the TX?
Thanks!!
Wali
Can you go over barometers and other parts not to coat or how to uncover if you have coated them?
soak it with alcohol, the coating should dissolve. Then leave it to dry completely.
seems like this stuff just killed my board … not sure how , I used this stuff on many board before , maybe I put on too much …
what can I dip the board in to remove it ? just alcohol ?
Nice job, different conformals are a good cheap solution for moisture control, but unfortunately, application methods often cause more issues than they resolve. Your explanation is most helpful and anyone wanting to try conformal coating should read it all t.o avoid many of the pitfalls that can occur.
Anyone using Tropicoat (electronicaembajadores.com/en/Productos/Detalle/HR11060/tool-instrument/aerosol-spray/jelt-7361-tropicoat-400-ml-tropicalised-varnish)? I’m using it but don’t know if it’s doing a good job?
Hi Oscar,
It’s important to say, waterproofing component isn’t cover by the warranty.
It’s happened to me, twice, with two different ESC and each reseller won’t take my product. (Considered like a modification)
So i prefer protect them from humidity and hope they can survive in the water with no warranty than a burned component without warranty anyway :p
A very big thanks for all your work ! you help so much the FPV community ;)