Pixhawk reliability in high humidity tropical locations

I’m hoping for some help from someone with experience flying in areas with high humidity. We are building a Pixhawk hexacopter for aerial surveys as part of archaeological research and the two locations we will be flying are Greece and Mexico. I understand that high air temp isn’t really an issue, but one concern we do have is the high humidity of the survey location in Mexico.

Do we need to take precautions to protect the FC from the humidity?

Thanks for your help!

If you get condensing humidity you get a massive problem unless the electronics are prepared for that. This can even happen with temperature change, i.e. you bring your cold equipment into a warm room and on the pcb the water condenses. You will have this problem with every electronic part i.e. Tx, Rx, VideoTx, VRx, etc. not only FC. Parts that produce heat like ESC are usually less affected as the other stuff quits first.

So would using conformal coating on all electronic parts be the solution?

I have no solution, just mediocre compromises. Problem is you cannot coat everything - i.e. you don’t want to coat the barometer. Another possibility is using boxes and silica gel.

I suppose compromise is the best it ever is and all I can do. ESCs can be coated no problem, as can the PDB. RX, VTX and telemetry have connections so can only be partially coated I guess. Avoiding the baro and connections on the Pix should be easy enough though. Perhaps placing small sachets of silica gel inside the Pix casing will reduce condensation on the parts that can’t be coated.

It seems we’ll need to add acclimatising the machine before use to the pre-flight checks.

Thanks for your help, Markus.

We operated a large Octo in the Gulf of Carpentaria for a month with the copter spending many nights sitting on a table amongst the mangroves with the water lapping at the legs of the table.
I would call that a humid environment :slight_smile:

There is a product we used called CorrosionX
It is messy, slightly oily and will dissolve hot melt glue and over time harden PVC insulation.
But once you coat a circuitry it can literally operate underwater.
Seems to have no effect on potentiometers, baro’s, and the like.
Messy but it works.

Might be worth checking out.

I’ve seen that stuff on YouTube and it does look messy! I was looking at Electrolube HPA - http://www.electrolube.com/products/conformal-coatings/hpa/acrylic/ - or something like they use in this video - https://youtu.be/HOu5hRqSDtU. I’ve used liquid electrical tape on my small racing quads in the past and that’s quite messy.

I can substantiate Mike’s comment above regarding Corrosion X. I live in northern ontario canada and it’s winter for what seems like 9 months of the year lol. Anyways I deal with heavy condensation on all my rigs when ever they are brought back indoors. Because of this we would normally open everything up as best we could then lay silicone packs near everything we couldn’t access.

We started using Corrosion X and obviously we would still have condensation form but the wter is repelled from everything that is coated in the spray.

You can most likely find corrosion x for sale at most large marine and boat dealerships.

One thing to note is that corrosion x DOES NOT waterproof ESCs…that requires a completely different process.

That’s good to know. I think a combination of CorrosionX, conformal and silica beads is the way to go.

Thanks all!