Putting a wet phone in rice vs. leaving it in an open space

[greypilgrim]

Hi.

The usual recommendation for a phone that got wet is not trying to turn it on again and place it in rice overnight as the rice will absorb humidity.

But is there any advantage over leaving it in a big, maybe ventilated room (and maybe placing it upright)? If a water molecule leaving the phone gets absorbed by the rice or just flies off shouldn't make a difference, should it?

 

[DaveC426913]

A thought experiment:

If evaporation happened as fast as absorption-by-rice then you could put a drop of water on the table, and place a pile of rice touching it, and the water should evaporate just as fast as it gets sucked into the rice.

If you ran this experiment, which way do you think the water is likely to go? Into the air, or into the rice?

Follow up question: Can you think of reason why it might be preferable to remove the water as fast as practical, rather than at a leisurely pace? What does water do if left to its own devices on metallic parts?

 

[greypilgrim]

Well the rice isn't touching the water inside the phone, is it? And I'd surely dry off the water on the outside first before placing it in the rice.

 

[DaveC426913]

Fair enough, but water likes to wick. The more water you draw away from any cracks or openings, the more water can be drawn out from inside.

 

[Frabjous]

I think the relevant physics is vapor pressure. The rice in a CLOSED container absorbs moisture, creating a lower humidity environment which increases evaporation. At some point, a low humidity environment with circulation would be equivalent, but I do not know the humidity level.

 

[greypilgrim]

I think the relevant physics is vapor pressure. The rice in a CLOSED container absorbs moisture, creating a lower humidity environment which increases evaporation. At some point, a low humidity environment with circulation would be equivalent, but I do not know the humidity level.

Does that mean I'd need rice from a sealed package? I reckon any rice that had been stored in contact with the ambient air would already have absorbed enough water to be in equilibrium with that vapor pressure again.

 

[Frabjous]

Does that mean I'd need rice from a sealed package? I reckon any rice that had been stored in contact with the ambient air would already have absorbed enough water to be in equilibrium with that vapor pressure again.

It lowers the humidity in the air so that the water on the electronics evaporates faster. Googling the topic, there are sites that say it doesn’t work, so it might be an urban myth. On the other hand, I do not have a better desiccant handy at home.

 

[DaveE]

1) A "ventilated room" in Pensacola usually isn't the same as in Tucson.

2) If rice is the best desiccant you've got it can't hurt. You can buy real desiccants from amazon and get them the next day.

It's all about the humidity of the air next to the water you want to remove. Key words: "humidity" and "next to". Remember, you are using air to transport water away from your phone to some other place.

 

[A.T.]

The usual recommendation for a phone that got wet is not trying to turn it on again and place it in rice overnight as the rice will absorb humidity.

There are many recommendations. One is to rinse it with isopropanol to flush out the water and the stuff that was floating/resolved in it. The isopropanol then evoporates cleanly without resudiuals.

But is there any advantage over leaving it in a big, maybe ventilated room (and maybe placing it upright)? If a water molecule leaving the phone gets absorbed by the rice or just flies off shouldn't make a difference, should it?

I'm pretty sure people have already tested this. I remember a youtube video which didn't find much advantage in using the rice. But there are too many factors at play to give a general answer.

 

[snorkack]

There are many recommendation. One is to rinse it with isopropanol to flush out the water and the stuff that was floating/resolved in it. The isopropanol then evoporates cleanly without resudiuals.

It might be logical, except that I see warnings that specify acetone and ethanol as dangerous for electronics - probably to plastic parts. Since isopropanol is of comparable polarity, it would have same objections. (Methanol would be slightly less polar).

 

[A.T.]

It might be logical, except that I see warnings that specify acetone and ethanol as dangerous for electronics - probably to plastic parts. Since isopropanol is of comparable polarity, it would have same objections. (Methanol would be slightly less polar).

I have used isopropanol once, with a phone that had been in apple juice, which then dried. I didn't disassemble the phone, just bathed it in isopropanol and sprayed it into the openings. So I don't know what it did to the plastic inside. It substantially improved the function of the phone, but didn't completely fix it. Display still had dead zones.

 

[JT Smith]

I have a relatively old phone and it's highly water resistant. When it gets wet I just towel it off.

An even older phone? You could do better than a bag of rice for a DIY desiccator (do a search) but the basic idea is to put it somewhere warm (90°F should be safe) and dry. If the water was going to damage the electronics it's probably too late anyway.

You could crack a phone open with a few minimal tools to facilitate drying. But it's a little risky if you're not skilled.

 

[greypilgrim]

It lowers the humidity in the air so that the water on the electronics evaporates faster.

But if I use rice that has been in contact with room air for a while, wouldn't it already have absorbed enough water to be in equilibrium with the vapor pressure of the air? Why would it still lower the humidity of the air around the phone?

It's all about the humidity of the air next to the water you want to remove. Key words: "humidity" and "next to".

Why is the humidity of the air next to the phone significantly higher? When in a big room a water molecule flies out of the phone, why wouldn't it fly off but linger around the phone?

 

[sophiecentaur]

You could crack a phone open

YouTube will tell you how to get inside almost any piece of electronics. Open is way better than closed. If you see actual droplets inside then remove them with the corner of some kitchen towel. Removing the battery will help to avoid too much corrosion whilst you wait for drying out to complete. A fan will help improve the drying rate whether open or closed.

 

[jrmichler]

The usual recommendation for a phone that got wet is not trying to turn it on again and place it in rice overnight as the rice will absorb humidity.

Similarly, the recommendation for wet running shoes was to stuff them with newspapers to absorb the water. So I ran some tests. Running a few miles in heavy rain gets the shoes just as wet as running in knee deep water. I stuffed a pair of wet shoes with newspaper. An hour later, the paper was damp, so I replaced it with dry paper. After repeating several times, the shoes were still wet the next day.

It's all about the humidity of the air next to the water you want to remove. Key words: "humidity" and "next to". Remember, you are using air to transport water away from your phone to some other place.

The next test was a boot dryer like this one:

That got the wettest shoes completely dry before the next morning. I put a remote reading thermometer into my shoe dryer earlier today. The temperature inside the shoe is 110 deg F. That's enough to get the relative humidity from a typical 20% to 50% down to less than 10%. The low humidity, along with a continuous flow of air, dries the shoes very nicely. An additional benefit to always having dry shoes is that the shoes last longer.

Why is the humidity of the air next to the phone significantly higher? When in a big room a water molecule flies out of the phone, why wouldn't it fly off but linger around the phone?

There is a boundary layer of air next to any surface. Moving air makes the boundary layer thinner, which increases the moisture gradient, which increases the rate of evaporation.

I suggest gentle heat on the phone - about 110 to 120 deg F for a couple of days. Be very careful to not overheat it.

 

[hutchphd]

The circuit board will be happier to have the water + ionic contaminants wicked away rather than evaporatively dried in situ (thus concentrating ionic dendritic contamination) I vote Rice.
I also always put some in my salt shaker.

 

[gmax137]

Maybe worthwhile to pre-dry the rice by putting it in a warm oven.

A coworker had dinner at his elderly mothers house. She was doing the dishes afterwards so he told her to go sit while he finished them. When he got to the bottom of the sink, he found his digital point and shoot camera. After a week in the rice, it worked fine.

 

[DaveC426913]

Maybe worthwhile to pre-dry the rice by putting it in a warm oven.

Well if you have an oven you might as well just bypass the rice altogether ...
phone > oven.

 

[gmax137]

Pan roasted android, yum!

 

[DaveE]

Well if you have an oven you might as well just bypass the rice altogether ...
phone > oven.

Many ovens either won't have a warm setting, or won't do it well. Also, be mindful of radiant heating of the object, the phone may get much hotter than the air. It's a great idea if you can do it, but don't cook your phone.

Also, unless you can open it, water transport out of the phone may be a slow process. Vapor inside may recondense when it cools later.

 

[jrmichler]

I used the warm location method to dry my Garmin Forerunner 310xt when the display fogged. It took about one day after setting on the heater in my shop. That heater is about 120 F when running.

Pan roasted android, yum!

Pan roasted battery, BLAM. The electronics will tolerate much higher temperatures, but I assume that 120 deg F is safe for the battery.

 

[jrmichler]

Finally, an authoritative answer for drying phones: https://gizmodo.com/apple-warning-against-wet-iphone-rice-bath-heat-1851269963.

The headline: Apple Officially Warns Users to Stop Putting Wet iPhones in Rice. From the article:
Saving a wet iPhone by putting it in a bowl or bag of uncooked rice has been a popular go-to rescue method for years, with the logic being that the rice absorbs the excess water from the phone. However, the God of iPhones has recently warned poor mortals against resorting to rice in these situations, saying it could make things worse.

In a recent support document, Apple states that putting wet devices in a bag of rice could “allow small particles of rice to damage your iPhone,” although it doesn’t go into further detail. The company also recommended against using other well-known hacks, such as using an external heat source to dry the phone or sticking a cotton swab into the connector.
The link in that quote is: https://support.apple.com/en-us/102643.

 

[DaveC426913]

I don't suppose they deign to say what their reco is for rescuing a phone from a dunking?

 

[gmax137]

I don't suppose they deign to say what their reco is for rescuing a phone from a dunking?

Is obvious, buy a new phone, lol.

 

[DaveE]

Apple states that putting wet devices in a bag of rice could “allow small particles of rice to damage your iPhone,”

Really? They make phones that can be ruined by "small particles" on the outside? Better not put it in your pocket either then.

Although I do suppose rice could plug up the microphone or speaker holes. Which, BTW, is an improvement over a completely broken phone. Perhaps you could de-rice the phone later?

Real desiccation chambers will have something like a shelf to keep your stuff away from the desiccant.

Maybe it's really the ziplock bag they are warning about?

 

[DaveC426913]

Perhaps you could de-rice the phone later?

The recommended method for de-ricing a phone is to rinse it in water.

 

[JT Smith]

Is obvious, buy a new phone, lol.

For sure. I took my three year old phone in for a new battery and the Apple guy who gave me my phone back told me he hoped that I'd get a new one before too long. Why would he care? Is he worried about his Apple stock or something?

That said, if you still have a phone old enough to have such poor water resistance that you need to worry about how to dry it out if it gets wet then maybe it is time.

Get a new phone!


Back in the day, before I had a phone with a camera and was still using a P&S camera, I got my camera wet in the rain on an overseas trip. It was not waterproof. I bought a tiny, tiny screwdriver and opened it up. And then I used the hotel hair dryer on it for about twenty-five minutes. It worked... until I got sand in the lens mechanism a week later. That killed it.