Greetings all,
I'm new to this forum and wanted to check in with the P-cola area MP pilots. I live on Perdido Bay (on the Alabama side) and do most
of my flying over and around the bay staying clear of the east side of the bay (away from Ferguson Field and NAS foot prints). As an
aside my MP went into Perdido Bay last Saturday and sat in 4 feet of salt water for about 10 minutes or so. I immediately pulled out the battery and flushed the drone with fresh water from a hose at our boat house. Took the drone up to the house disassembled it and sprayed the circuit boards and other components with CRS Electronics Cleaner to clean away any residual salt/minerals. If you haven't
taken your MP apart DJI has applied a clear protective coating on the CBs to provide some water proofing. The CRS Electronics Cleaner that I used not only cleans but is hydrophobic as well. I then used the wife's hair dryer (just air, no heat) to dry all of the components then
let them sit over night. The next day I re-inspected the CBs using a magnifying glass to look for traces of salt/mineral deposits. I found a few small areas of salt/mineral residue and used a soft bristle toothbrush and CRS Electronics Cleaner to carefully clean those areas.
I let the components air dry for a couple of hours then reassembled the drone. I put a freshly charged battery into the MP (the battery
that was in the drone at the time of the incident fried itself) turned it on and it powered up as if nothing had happened. By then it was late in the day so I just took off and hovered at about 6 ft to check the systems and flight characteristics - everything appeared to be normal.
I've flown the drone 5 or 6 times since then and the bird flies as if it had never taken the salt water bath.
Just my opinion but covering a MP that has been submerged in water (fresh or salt water) in rice for several days is not the way to go.
1) The rice doesn't come into direct contact with the water inside the tightly closed outer shell o the drone. Therefor there is very
little moisture "wicking" into the rice. The moisture mostly evaporates into the atmosphere leaving a salt/mineral residue on
the CBs and other components like scum on the inside walls in a bath tub when the dirty bath water is drained out.
2) Large bags of rice typically have small amounts of "rice dust" cause by the grains of rice rubbing against each other. Some of that
dust can make it's way into the inside of the drone and become part of the residue left behind after the moisture evaporates.
3) Even if the moisture inside the drone did wick into the rice the minerals suspended in that moisture would remain and form a residual
coating on the internal components of the drone.
4) The burying the drone is rice method takes days to dry out the drone. That means that the moisture and it's harmful contaminates
sit unopposed for days leaching corrosive substances into the innards of your drone.
Having your drone submersed in water (seawater or fresh water) requires aggressive intervention, it is imperative that the battery
be removed ASAP, and the drone be washed/flushed with clean water immediately. It is also imperative that the drone be quickly dismantled and the circuit boards and other components (including the motors) be thoroughly cleaned with 99.1% isopropyl alcohol (can be hard to find) or an electronics cleaner (specifically formulated for cleaning circuit boards, contactors, etc.) and only after the sensitive
electrical components have been cleaned should the drying process be attempted.