Crash your Drone? In the WATER? Hers an easy fix.

[umanbean]

Calculate the two weight changes. What is the weight change in the rice and does it match the weight change of the container and water?

Wow. And after all that - it's no secret that dried white rice absorbs water, how else would it get soft and fluffy and moist when you cook it. So it would follow that it also absorbs water vapor.... that makes it an impromptu desiccant, if only a poor one. No disrespect to you or sar104, but it doesn't take a genius to figure that out.

 

[old man mavic]

I just love the way that the good old rice remedy ,pops up from time to time on the forum,and all the effort that goes into explaining ,why it is so wonderful, or not ,for drying out a drone ,that has been in the water
it doesn't really matter, what side of the fence you sit on ,on this subject ,water of any sort ,and indeed other sorts of liquids, if they get onto the electrical components in a drone,can and will do damage, whether it happens instantly ,or at some point down the line ,any drone that has been subjected to immersion,should be deemed to be unairworthy ,IMHO

 

[Yorkshire_Pud]

Wow. And after all that - it's no secret that dried white rice absorbs water, how else would it get soft and fluffy and moist when you cook it. So it would follow that it also absorbs water vapor.... that makes it an impromptu desiccant, if only a poor one. No disrespect to you or sar104, but it doesn't take a genius to figure that out.

When you cook rice it is immersed in hot-to-boiling water or steam at 100C, it is not trying to absorb room temperature water vapour from the air.

 

[MS Coast]

Three thoughts occur to me concerning this thread.
1) There are those who believe rice to be an effective desiccant and there are those people who do not, neither will ever agree with the other.
2) If rice is not a desiccant then sealing a wet drone in an air tight plastic bag it possibly detrimental to the drone as it may keep water in the liquid state due to the air in the bag being 'saturated'. One for @sar104 etc. perhaps.
3) Someone with accurate scales could perform an experiment.
Weigh, to 0.1g or less, a reasonable quantity of rice from a just opened bag and keep a record of that weight. Pour that rice into a zip lock plastic bag and the place that zip lock bag inside another zip lock bag put the bags somewhere with constant temperature that is safe and flat so that the bags can lie flat and undisturbed for perhaps a week.

3a)Weigh, to 0.1g or less, and record the weight of some sort of small, open topped, plastic container that is partially filled with room temperature water.
Without splashing out any of that water, place the container and water inside the inner zip lock bag and seal both bags. Ensure that the top of the container remains open, so that the air and water vapour can circulate within the inner bag. Leave the whole shebang undisturbed for whatever time period was chosen.

At the end of the time period remove the container and water from the bags and weigh, to 0.1g or less, the container and water. Remove the rice from the bags and weigh it, to 0.1g or less.
Calculate the two weight changes. What is the weight change in the rice and does it match the weight change of the container and water?

That will simply show that rice does absorb water. It does. That's known. It just doesn't absorb as much water as other materials developed specifically as desiccants.

Desiccants do no drying when they're already reached their capacity for storage water. Chemical desiccant packs for drying electronics have simple color indicators that reflect their moisture content. If they're "wet" you dry them in an oven before using them. Rice? You have no way of knowing its moisture content. (It's interesting that rice rescue advocates never consider the moisture content of their rice or how to reduce it before using it.)

People who work with, maintain, and repair electronic gear don't use rice. There's no readily available scientific test results showing that rice is an effective desiccant for drying electronic gear and preferable to chemical desiccants. China grows lots of rice, but DJI doesn't put a packet in the boxes with the drones they ship.

Popular culture loves simple solutions to problems that "baffle the scientists" and "prove the experts wrong." Rice for rejuvenating dunked electronics has joined the classics, like "Aeronautical engineers say bumble bees should not be able to fly!"

 

[umanbean]

When you cook rice it is immersed in hot-to-boiling water or steam at 100C

The high temp is to speed up and/or enhance absorption. You can also add spices to it

 

[Yorkshire_Pud]

That will simply show that rice does absorb water. It does. That's known. It just doesn't absorb as much water as other materials developed specifically as desiccants.

But will rice straight from a freshly opened pack absorb, at room temperature, water vapour from the air and significant quantities of water vapour at that?

The high temp is to speed up and/or enhance absorption. You can also add spices to it

Again, that is liquid water or hot steam, does the same thing apply to room temperature water vapour?


I do not know and don't have the scales to make the measurements.

 

[MS Coast]

But will rice straight from a freshly opened pack absorb, at room temperature, water vapour from the air and significant quantities of water vapour at that?

Again, that is liquid water or hot steam, does the same thing apply to room temperature water vapour?


I do not know and don't have the scales to make the measurements.

The rice in the kitchen cabinet has reached equilibrium with the water vapor content of the air in the kitchen. It's only going to absorb moisture if it's placed in an environment with a higher water vapor level. If it's put into a sealed container with a wet drone, it's going to eventually stabilize at a moisture level above the room conditions on the shelf.

The typical packaging isn't moisture impermeable. And even if the rice was packaged in a totally sealed and impermeable bag it would only be as dry as the place where it was put in the bags.

If I was on a fishing trip in the remote Canadian wilderness and dropped an electronic gadget in the lake and didn't have desiccant packs, I might give rice a shot as a last resort. But I'd dry it out in the wood stove's warm oven for a few hours before putting it in the empty pickle jar with the dunked gadget. But if it was good locally harvested wild rice and the gadget wasn't too expensive, I'd probably just eat the rice with the trout from the lake.

 

[umanbean]

But I'd dry it out in the wood stove's warm oven

To clarify,
that's dry out the rice,
and not the device

Can I go fishing with you sometime? Spicy rice and trout sounds MmmMmm good!

 

[Yorkshire_Pud]

The rice in the kitchen cabinet has reached equilibrium with the water vapor content of the air in the kitchen. It's only going to absorb moisture if it's placed in an environment with a higher water vapor level. If it's put into a sealed container with a wet drone, it's going to eventually stabilize at a moisture level above the room conditions on the shelf.

The typical packaging isn't moisture impermeable. And even if the rice was packaged in a totally sealed and impermeable bag it would only be as dry as the place where it was put in the bags.

If I was on a fishing trip in the remote Canadian wilderness and dropped an electronic gadget in the lake and didn't have desiccant packs, I might give rice a shot as a last resort. But I'd dry it out in the wood stove's warm oven for a few hours before putting it in the empty pickle jar with the dunked gadget. But if it was good locally harvested wild rice and the gadget wasn't too expensive, I'd probably just eat the rice with the trout from the lake.

That might tie up with something that has just come to mind I was about to post.
From grains of hard rice that I have found around the house in places where uncooked rice would NEVER be i.e. cooked rice that has fallen off a plate, I presume that 'wet', cooked rice dries out when exposed to the open air.

I think it would be interesting to know, on a g for g basis, how much water vapour nominally dry rice can absorb from the air at room temperature.

 

[old man mavic]

all this talk about rice ,convinced me to just have a nice bowl of boiled long grain rice,with chicken and black-bean, and water chestnuts for my evening meal, as i sat in my man cave ,at my computer , and very nice it was to ,and i checked to see if i had dropped any ,but fortunately i hadn't on this occasion

 

[umanbean]

I think it would be interesting to know, on a g for g basis, how much water vapour nominally dry rice can absorb from the air at room temperature.

Yes that would be interesting to know, but not for the purposes of this discussion I think. The changes in heart rate, pumping ability and appetite of the average Space Station long-term astronaut would also be interesting... to a point.

 

[Droning on and on...]

I think it would be interesting to know, on a g for g basis, how much water vapour nominally dry rice can absorb from the air at room temperature.

As reference, a quick Google search turns up a ratio of approx 1:1 to 1.5:1 water:rice by volume or weight for food applications. It's imprecise because we're talking cooking food, so the ending saturation, and therefore texture and consistency, is going to vary based on recipe and personal preference.

This, of course, is much more saturated than would be intended in any dessicant application of rice.

As far as commercial/industrial dessicants, you all can find more than you ever wanted to know at this site, with plenty more fodder to argue about.

 

[Yorkshire_Pud]

Yes that would be interesting to know, but not for the purposes of this discussion I think. The changes in heart rate, pumping ability and appetite of the average Space Station long-term astronaut would also be interesting... to a point.

Ooh could you book me on the next flight to the space station please?
The knowledge would I think go a long way to settling the it's-a-useful-deseccicant /it's-of-no-use-as-a-desiccant debate.
I think its best we end our discussion.

and water chestnuts

mmmmmmmmm, pity there's no mouth watering emote

 

[MS Coast]

As reference, a quick Google search turns up a ratio of approx 1:1 to 1.5:1 water:rice by volume or weight for food applications. It's imprecise because we're talking cooking food, so the ending saturation, and therefore texture and consistency, is going to vary based on recipe and personal preference.

This, of course, is much more saturated than would be intended in any dessicant application of rice.

As far as commercial/industrial dessicants, you all can find more than you ever wanted to know at this site, with plenty more fodder to argue about.

Hmm. The graphs of water absorption capacity don't have any values plotted for rice. Silica gel looks pretty darn good, though.

 

[umanbean]

The knowledge would I think go a long way to settling the it's-a-useful-deseccicant /it's-of-no-use-as-a-desiccant debate.

And if it turned out to actually be useful or not, could you spread that information across the internet as far and wide as the rice myth? Reinforcing or debunking every mention of it on every website? Or just for the eyes of the participants in this thread?

 

[Droning on and on...]

If I was on a fishing trip in the remote Canadian wilderness and dropped an electronic gadget in the lake ... dry it out in the wood stove's warm oven for a few hours

^^^This.

If you (reader) have any formal college-level physics in your background, surely you know this is extremely more effective than any dessicant, rice, pasta, sucking real hard on the back of the drone, etc.

Heat. Literally hundreds of times (WAG, probably more) more effective at getting those water molecules all worked up, angry, buzzing around in there trying to get out of your drone. The siren call of a distant dessicant at room temperature is way less effective at getting those little guys to stop clinging to everything and each other with surface tension.

That's always been my solution. Oven at 150°F, leave the phone, whatever, in there for 3-4 hours. Has worked for me every time.

Those among us that hobby in 3D printing as well as these mechanical gnats know this heat vs dessicant issue well, especially if experienced with nylon filament.

 

[Droning on and on...]

That might tie up with something that has just come to mind I was about to post.
From grains of hard rice that I have found around the house in places where uncooked rice would NEVER be i.e. cooked rice that has fallen off a plate, I presume that 'wet', cooked rice dries out when exposed to the open air.

I think it would be interesting to know, on a g for g basis, how much water vapour nominally dry rice can absorb from the air at room temperature.

Like, well, everything, rice simple moves toward water vapor equilibrium with the Relative Humidity of the air it's immersed in.

So, depending on how moist or dry it is, the RH, temperature, it will absorb water vapor or outgas it.

The same is true for absorptive dessicants. Chemical dessicants, on the other hand, remove the H2O from the environment by chemical reaction, so do not re-release moisture when the air is dryer than the dessicant.

 

[Droning on and on...]

Kicking myself for not keeping my mouth shut.

 

[Yorkshire_Pud]

Aeronautical engineers say bumble bees should not be able to fly

Haven't they cracked that, something about moving the wings back af forth rather than up and down with the wing pitch being reversed with the change of direction?

 

[Yorkshire_Pud]

And if it turned out to actually be useful or not, could you spread that information across the internet as far and wide as the rice myth? Reinforcing or debunking every mention of it on every website? Or just for the eyes of the participants in this thread?

No, I will leave that up to you.