Rescuing wet electronics

[GeeTwo]

Originally Posted by Ether

The OP did say "rainwater", but he also said "flash flood", so it's unclear how clean was the water that got into the bot.

By definition, flood waters have been in contact with the ground, so as I read OP and subject to clarification, I agree that this would not be "rainwater" for purity considerations. Even if it were water that got into a building from above, unless there was a gaping hole in the roof, the water probably passed through some building materials that would leave unsavory deposits on your electronics.

Originally Posted by Ether

Also, is the rainwater in NYC cleaner than LA rainwater?

Considering the quality of the air that the rain passes through going from cloud to ground, probably so.

[FrankJ]

Originally Posted by Ether

The OP did say "rainwater", but he also said "flash flood", so it's unclear how clean was the water that got into the bot.

Also, is the rainwater in NYC cleaner than LA rainwater?

Don covered what to do pretty well for dirty water. I did not feel the need to repeat it. I have had laptops hosed down with white water & pulp from paper machines. Fairly dirty from an electronics point of view. I washed them out in the bathroom sink & put them upside down on the hotel air conditioner to dry. YLMV on this. (Your luck may vary.)

I am by no means an expert in this, but with enough rain to qualify as a flash flood, I would think the rain water would be pretty clean wherever you are.

[GeeTwo]

Originally Posted by FrankJ

I am by no means an expert in this, but with enough rain to qualify as a flash flood, I would think the rain water would be pretty clean wherever you are.

Quite the contrary. While in-place flash floods are possible when you actually have more than 6" of rain in 6 hours (e.g. here on the Gulf Coast), most flash flooding is the result of rapidly moving water. Rapidly moving water picks up silt, sand, and even rocks, houses, and bridges if it's moving fast enough. If you check out the Wikipedia page on flash floods today, you will find three pictures. All of them show dirty water.

[FrankJ]

Originally Posted by GeeTwo

Quite the contrary. While in-place flash floods are possible when you actually have more than 6" of rain in 6 hours (e.g. here on the Gulf Coast), most flash flooding is the result of rapidly moving water. Rapidly moving water picks up silt, sand, and even rocks, houses, and bridges if it's moving fast enough. If you check out the Wikipedia page on flash floods today, you will find three pictures. All of them show dirty water.

That would be flood water. (your definition) And you are correct It picks up stuff from places that regular run off does not so it tends to be dirtier. Especially when it overwhelms cache basins. Rain water is the stuff that comes out the sky and becomes flood water when it reaches the ground.

[themccannman]

Number one concern is any minerals/salts in the water that contacted the parts. Rain water is pretty clean but not necessarily entirely exempt from containing this contaminants so whether it was rain or flood water there is still a risk. Number one priority is to disassemble everything, wash it all with distilled/deionized water to remove any mineral deposits, then wash with alcohol and let everything dry. As long as nothing was powered on and you washed everything thoroughly it should all be as good as new.

[GeeTwo]

Originally Posted by FrankJ

That would be flood water. (your definition)

Actually, this definition of a flood was borrowed from FEMA. It's not verbatim, but it's essentially the definition that applies to federal flood insurance. Yes, I'm one of those weirdos who actually reads the policy every few years.

[F22Rapture]

Originally Posted by ChuckDickerson

I have worked in marine research area for years. Several years ago I was involved in a vessel sinking offshore. We had in excess of $200,000 of marine data collection instrumentation on board that went to the bottom. We called in divers and a vessel salvage crew and raised the vessel within 24 hours. When the divers brought up the vessel and gear I quickly opened up all the electronic deck boxes and flushed away the salt water with distilled water then the distilled water with isopropyl alcohol then dried everything as best I could with paper towels and spray cans of air, and a hair dryer. I let everything air dry for a few days. All the equipment still works fine to this day. We lost a few laptops but no data. The laptops were the cheapest thing on board and the data on the hard drives were more valuable. We ripped the hard drives out of the laptops and flushed them the same way. Sent the hard drives to a data recovery service and didn’t lose a single byte of data.

My suggestion is distilled water then isopropyl alcohol then dry as best you can. Spray cans of air to get in all the little crevices.

Member of an underwater robotics team in college here - this is what I suggest. Good advice

[philso]

Originally Posted by ChuckDickerson

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My suggestion is distilled water then isopropyl alcohol then dry as best you can. Spray cans of air to get in all the little crevices.

Yes, do this. Most boards get washed (often with water) though some components, DIP switches, are not designed to be washable.

Un-mate all connectors, flush with clean water then alcohol and let dry.