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Conformal coating can absolutely save your quad from water

It’s no secret that conformal coating offers tremendous protection for electronics against moisture and even full-blown immersion. So let’s take a look at what to use and how to use it.

The first time I saw conformal coating it was a bit like magic. A guy in the Toronto FPV scene had a small shop and gave me a demo. He had a flight controller and ESC that were wired up, using longer cables, to a battery and a motor. He had a small, clear container filled with water. He dropped in the flight controller and ESC, then – away from the water – plugged in the battery. He grabbed a radio and spun up the motor.

It worked perfectly – and looked like magic.

What is this stuff?

Basically, conformal coating is a layer of liquid plastic that you apply in a manner similar to the way nail polish is applied. Using a small brush, you cover your components and let this stuff dry. Generally, that film is from 25-75 µm thick, with 50 µm being about average (that’s about .05 mm). But that’s more than enough to keep out water, humidity, dust, and other contaminants that might be in the air.

It’s called “conformal” because it conforms to all the tiny nooks and crannies you’ll find on a circuit board. And while you can cover up complete integrated circuits and soldered connections with this stuff, you should not be applying it inside plugs.

What product do people use?

A quick online search seems to indicate that products made by MG Chemicals are the most popular – and the stuff with silicone. A small 55 ml bottle should last you a very long time and will cost you about $20. Compare that to the cost of frying components on your quad.

We were reminded of the value of conformal coating after writing about our pilot pal in France. If you missed that story, here’s the bottom line: His quad crashed into the pool of water at the bottom of a freezing waterfall. It was underwater for about five minutes. The pilot climbed in the water and rescued his quad:
That looks SO COLD. But the drone survived!!


It’s not just submersion!

People often think conformal coating is all about protecting the quad in scenarios like this, rain or snow. And while it will offer protection in all those scenarios, it offers much more. Landings on moist grass often allow bits of water to reach the electronics. Flying over a beach, the surf crashing in, can expose the drone to saltwater mist, which can really wreak havoc over time. Even fog can quickly condense on a drone.

Oh – you might have an option when purchasing for regular or “modified” conformal coating. The modified stuff glows under UV light, which makes it really easy to see if you’ve coated everything or not.

If you’re curious, there are a ton of YouTube videos out there with people showing you their own special tips and tricks for applying conformal coatings to quads.

Happy – and dry – flying!