So today 11/16/2016 I get word of rain/snow on Friday 11/18/2016. This will be the first snow of the season and made me re-double my efforts to get at least one wet capable multirotor up and running. Last year I had terrible luck and blew out more components then sessions I actually flew. Water and salt from the roads kills things quick. There are a few options out there that I know of that work. (Disclaimer: You do this at your own risk. I am not responsible for any damage due to this modification.)
1.) DryDrone – I know nothing about this product but it’s supposed to be tailored directly for use with multirotors.
2.) CorrosionX – Great in a pinch but leaves a nasty residue and attracts dirt and debris. FliteTest did a great video on using it here.
3.) Conformal Coating – Silicone is the best. Not very durable but makes for easier rework if you have to solder through it.
4.) Clear Nail Polish – Any nail polish will work but a thick coat of this should protect things well. Not easy to rework anything after it’s on there though.
5.) Epoxy – The longer set stuff works best but don’t expect to do any work easily on the electronics after it’s on there.
6.) Liquid Electrical Tape – Works good to keep water out but very messy and doesn’t look very professional.
Now some things to keep in mind. You want to coat all PCB’s exposed surfaces to give you full protection including ESC’s but do not put any of these things on your motors. The motors will run even when under water as they are already insulated. Hot glue does not work as it’s permeable and does absorb moisture and doesn’t provide a water tight seal.
Something else to keep in mind some of these products do not react well to certain plastics and can cause them to deform or start desolving/melting. It’s always best to test them on something before hand to make sure you don’t have an issue.
Now if you didn’t treat your multirotor prior to getting it wet or maybe you missed a spot and it’s shorting out all is not lost. Best practice is to:
1.) Unplug Battery
2.) Rinse off any salt or other contaminants with distilled clean water.
3.) Spray WD40 on the electronics
4.) Wait for it to dry out completely 24-48 hours in a warm dry place
5.) Rinse and clean off the WD40 residue with more clean distilled water
6.) Dry it out completely
7.) Power up and see what does and doesn’t work.
This wraps up what I know works and if you would like to add a comment or suggestion feel free to contact me at the links in this blog.