A SALT WATER CRASH AND SURVIVED. HOW?

[Stortiz1]

I must put this story out because I swear I thought it was "curtains" for my MAVIC MINI. I live on the gulf coast of Mississippi. We are on the Gulf of Mexico. I fly my drone most of the time over water with no issues ever. Our water is not clear or highly reflective because of our barrier islands that block this type of water. The saltwater has a brown tint to it so the MAVIC MINI does not have issues. What happened was a pilot error (me) and I almost had a heart attack. I fly my drone through different harbors along the coast and fly in between shrimp boats from time to time. Unfortunately, I made a critical error and my drone plunged into the harbor. I freaked out and wet to the area where it fell into the water. I even dove in after it, however, the waters in the harbor are both deep and murky. You cannot see an inch past your face. The harbormaster gave me a name of a diver that said he could go for it the next day...

So the next day I met the diver. This was what I did that probably saved my drone, in this order. I had read about freshwater drownings of MAVIC and possible regaining a working drone. But could not find anything positive about saltwater crashes. So what I did was get two large 5-gallon buckets of fresh water. When the diver finally found the drone. (submerged for 15 hours) I immediately submerged the MINI in the first bucket. I had muck and sand all over it and the diver said he kept mistaking blue crabs for the drone because they were all around it. After 2 minutes of shaking the drone in the 1 st bucket, I placed it in a second bucket. I shook it again as the sand and muck seemed to be coming out of the fuselage. Then I pulled her out and rinsed her again with fresh water. The next thing I did was drowned her again in isopropyl alcohol making sure every component visible was exposed to alcohol. Finally, the last thing I did was buy a 16-pound bag of rice, put the drone in the middle of the bag, sucked as much air out as possible, and re-sealed the bag. Then I waited.

The diver cost me $85. I had heard that the batteries are fried and junked after water exposure. This battery, when I opened it, looked like it had been under water for 30 years. Completely destroyed. This left me not so sure the drone would make it. However, after a full 24 hours, I took her out of the rice. Threw a fresh battery in it. And fired it up. That was 2 months ago. This drone didn't even miss a beat and has performed exactly as it did the very day I bought it. In fact, I have a fleet of drones, and this one is my favorite.

So, in summary, a MAVIC MINI can survive overnight in saltwater, if following this procedure. I am sure there are many procedures that work, but this one for sure brought my MINI from death.

 

[Yorkshire_Pud]

You were lucky. Also, apparently rice has very little deliquescent value and the grains and dust can get EVERYWHERE.
What's the salinity of the water there?

 

[MS Coast]

Did you completely immerse the drone in isopropyl alcohol or just spray and wipe the outside?

 

[Stortiz1]

Yorkshire,

I was indeed aware of the dust particulates so I actually put the drone in a gallon zip lock and put the bag in the middle of the rice and had the ziplock bag open. So minimal dust fragments got into the drone. The muck and mud were more worrisome because the harbor is dredged. The typical summer salinity varies in the summertime between 18-22 parts per thousand (ppth).

MS Coast! Howdy from Long Beach. I literally went to family Dollar, brought the large isopropyl alcohol and sprayed it inside-outside, and drenched it. I made sure every part got wet because isopropyl alcohol helps dry the components from its volatility properties. In my opinion both the fresh water and the isopropyl alcohol saved the drone. Where are you located?

 

[MS Coast]

Yorkshire,

I was indeed aware of the dust particulates so I actually put the drone in a gallon zip lock and put the bag in the middle of the rice and had the ziplock bag open. So minimal dust fragments got into the drone. The muck and mud were more worrisome because the harbor is dredged. The typical summer salinity varies in the summertime between 18-22 parts per thousand (ppth).

MS Coast! Howdy from Long Beach. I literally went to family Dollar, brought the large isopropyl alcohol and sprayed it inside-outside, and drenched it. I made sure every part got wet because isopropyl alcohol helps dry the components from its volatility properties. In my opinion both the fresh water and the isopropyl alcohol saved the drone. Where are you located?

I hope that alcohol penetrated well enough to get the salt off the circuit boards and other internal components. You might anticipate some long-term issues to come up with the Mini having spent so much time in the saltwater.

I'm in Ocean Springs.

 

[MAvic_South_Oz]

Your process was just as I have been led to believe (and often touted here on the forum) to be the best method . . . well, minus the rice, silica gel desiccant works a lot better.

Sound like a success story, but after 2 months, is it worth taking shells off and checking boards etc, see what the inside components look like ?

"18-22 parts per thousand (ppth)" is this normal sea water level, or a little less ?
A quick google says normal sea water is 33-38 ppt, so that probably helped having nearly half normal salinity.

Hope it continues to give you good service for a long time.

 

[Stortiz1]

MAvic south,

That’s a good idea. I will open her up and check the boards. Yes the salinity is les but the particulates or the silty like water really bothered me. I did not know if she was going to purge that stuff or would it short something out. But it did not. Thank you for the advice.

MS COAST,

Yes I have been anticipating something happening by now. An oxidized component or something cracking . But it seems to be fine thus far, including the camera.
Hey is there a club or something or you ever fly with anyone? I seem to be the only flyer around Long Beach Pass Christian. Over in your parts there is a huge no fly zone as you know. Where do you like to go?

 

[MS Coast]

Your process was just as I have been led to believe (and often touted here on the forum) to be the best method . . . well, minus the rice, silica gel desiccant works a lot better.

Sound like a success story, but after 2 months, is it worth taking shells off and checking boards etc, see what the inside components look like ?

"18-22 parts per thousand (ppth)" is this normal sea water level, or a little less ?
A quick google says normal sea water is 33-38 ppt, so that probably helped having nearly half normal salinity.

Hope it continues to give you good service for a long time.

The salinity in the open Gulf is nominally about 35 ppt. Inside the barrier islands, in Mississippi Sound and along the coast, it's typically lower and strongly influenced by rainfall.

 

[EsaT]

Indeed the way biggest risk is in salt water soaked metal parts getting to contact with air and oxygen.
Salt basically works like catalyst for corrosion oxidizing things fast.
Pure water itself wouldn't be even electrically conductive.
But once you start adding things present in even in normal fresh water, it becomes more risky.
And salt really takes it up to twelve. (because up to eleven just isn't adequate)

So priority is in keeping that salt dissolved and flushing it away without giving it change to dry on surfaces.
That also minimizes exposure to oxygen.
Also pure water would have been good for extra stage.
Though IPA is definitely preferable for last flushing.


Not exactly drone, but shows well what salt water does for camera.

About Getting Your Camera Wet… Teardown of a Salty Sony A7sII

People think that because I expect the worst and try to prepare for it, that I'm negative. That's not it at all. I'm not a negative person; I'm cheerfully cynical. If I expect the worst and it doesn't happen, I'm happy because things went better than I expected. If I expect the worst and it does...

www.lensrentals.com

 

[chiangmaicharlies]

A good story - and happy ending. I once crash-landed my Mini in a flooded rice field. Retrieved it as soon as possible, whipped the battery out, cleaned it in clean tap water and left it to dry. Perfect next day. I was impressed.

 

[Drone-Retriever]

Check out drone-retriever.com for insight on how to clean a drone after a water event.
Note: Isopropyl alcohol is 70% water.

 

[MS Coast]

Check out drone-retriever.com for insight on how to clean a drone after a water event.
Note: Isopropyl alcohol is 70% water.

Pure Isopropyl alcohol has no water at all. The consumer product most commonly offered is 70% isopropyl alcohol mixed with 30% water. 90% Isopropyl alcohol (10% water) is also offered in many drugstores.

 

[EsaT]

Note: Isopropyl alcohol is 70% water.

Almost 100% IPA is easily available at least here in Finland.

 

[Phantomrain.org]

Let me just be the first one to day Bloody Miracle considering how many Mini 2 we have submerged under water.

That ESC module along with Chattering of the Camera has been a constant problem for the Mini 2 after submersion

Keep an eye out for the ESC errors .

I remember the bath tub taking out a mini, lol

Phantomrain.org
Gear to fly your Mini 2 in the Rain. Land on the Water .

 

[Stortiz1]

Well two months have gone by… no camera errors or any failures. I am going to open her up and check things out. I’ll take a picture.
Recap on salt water crash.
MAVIC MINI crashed next to a shrimp boat and sat in 18-22ppt salinity and mud overnight with blue crabs.
Diver found it 15 hrs later.
Immediately submerged it in two fresh water baths.
Used family dollar70% IPA and bathed it thoroughly.
Rice dried it in an enclosure within a 16 lbs or 7.2kg bag of rice.
Survived and no issues
Battery utterly destroyed

 

[eEridani]

The method you used is more or less industry standard for recovering electronics that have been immersed in salt water. Rice is a very good desiccant, despite all the comments that say otherwise (many government labs have done tests and found it is almost as good as a commercial desiccant). As for rice dust, well, have you ever looked at the bottom of a bag of commercial desiccant?

That said - the camera and gimbal would be the area of concern ... but if that is giving you good stable images, then the lens was sealed well enough and the alcohol did it's job.

Gratz.

 

[Stortiz1]

Hey I appreciate the post! My mini is still strong and completed a round of aerials for a local bar and grill. Literally, has not affected it. I also agree with the rice thing because 16 lbs of dry rice sealed with a semi damp drone will suck every bit of moisture in the sealed bag. But not many people want to pay for that much rice. It is a lot.

Yes I also have saved other electronics with alcohol and time. But the battery and the chemical reaction that was immediate was quite severe. Like I said, it looked like it had been submerged for 39 years.

 

[MS Coast]

The method you used is more or less industry standard for recovering electronics that have been immersed in salt water. Rice is a very good desiccant, despite all the comments that say otherwise (many government labs have done tests and found it is almost as good as a commercial desiccant). As for rice dust, well, have you ever looked at the bottom of a bag of commercial desiccant?

That said - the camera and gimbal would be the area of concern ... but if that is giving you good stable images, then the lens was sealed well enough and the alcohol did it's job.

Gratz.

I couldnt find any serious sources that endorsed rice ad a dessicant. Have any links to sources?

 

[Lennox]

Well two months have gone by… no camera errors or any failures. I am going to open her up and check things out. I’ll take a picture.
Recap on salt water crash.
MAVIC MINI crashed next to a shrimp boat and sat in 18-22ppt salinity and mud overnight with blue crabs.
Diver found it 15 hrs later.
Immediately submerged it in two fresh water baths.
Used family dollar70% IPA and bathed it thoroughly.
Rice dried it in an enclosure within a 16 lbs or 7.2kg bag of rice.
Survived and no issues
Battery utterly destroyed

Hey, so how does the internal boards looks ? Did any part became rusted?