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The problem with electronics in water is that water is an electrical conductor. So the circuit diagram for the board becomes "everything connected to everythin

The problem with electronics in water is that water is an electrical conductor. So the circuit diagram for the board becomes "everything connected to everything else all at once". Which means, at best it doesn't turn on. At worst it creates a short and current flows from one point to another, usually blowing up some part. Electronics and water therefore are seldom friends.

davidhyde 3y ago
Distilled water does not conduct electricity. It is the dissolved ions in the water that allow electricity to conduct. You may be able to clean the PI to such a level that nothing dissolves into the water when it is submerged. https://techiescientist.com/does-distilled-water-conduct-electricity/ https://techiescientist.com/does-distilled-water-conduct-ele...
- analog31 3y ago
  Getting it that clean is hard. There's stuff like residual flux under the ball grid arrays and other surface mount components.
  - namibj 3y ago
    AFAIK electrolysis will force you to utilize a scrubbing system anyways once you've got current passing through the water. But getting conductivity acceptably low is much less demanding than getting it this extremely low. E.g. some CO2 lasers are cooled with purified water to limit the current through it.
    - analog31 3y ago
      That's true. The YAG laser I used in grad school had the flash lamp inside a water jacket, and the light went through the water.
      - namibj 3y ago
        I mean things like CW CO2 tubes running in the kV range and being immersed in water with exposed electrodes.
- lbourdages 3y ago
  Even ultrapure water conducts electricity. It says right here [1] that its resistivity is 1.82×10^9 Ohm * m. This is a pet peeve of mine. We get told of conductors and insulators in school, but it doesn't work like that. Pretty much everything except a perfect vacuum conducts electricity. It's just that some materials conduct electricity so poorly that it can be rounded off to 0 in most circumstances, but there can still be measurable current flow. [1] https://en.wikipedia.org/wiki/Electrical_resistivity_and_conductivity?wprov=sfti1#Resistivity_and_conductivity_of_various_materials https://en.wikipedia.org/wiki/Electrical_resistivity_and_con...
  - bongodongobob 3y ago
    Ok, sure but 1.8 billion ohms puts you in insulator territory. Same ballpark as rubber or glass. So no, you shouldn't really consider distilled water a conductor.
    - namibj 3y ago
      It's actually quite conductive when you'd try to exploit it's breakdown strength as coolant and insulation for high voltage power electronics.
  - murderfs 3y ago
    A perfect vacuum conducts electricity as well: https://en.wikipedia.org/wiki/Schwinger_limit https://en.wikipedia.org/wiki/Schwinger_limit
FLT8 3y ago
Pure (eg. Distilled) water isn't a very good conductor at all. It's only when you add contaminant ions that it starts to conduct electricity in any meaningful sense. Most people's experience with water rapidly destroying electronics is probably with highly ionised water such as sea water or water in the washing machine which has washing powder added. Of course, it's worth pointing out in this case that as per the comments HZO claim they used water straight from the tap, so it's probably still an impressive enough achievement. I'm curious how they went about sealing the external connectors (usb, hdmi), because surely those would need to be exposed and with the voltage present would act as points of corrosion. The pins on the Pi connectors are quite tightly spaced too. Maybe the AC nature of most of the signals helps there?
- ajsnigrutin 3y ago
  Electronic are dirty, your keyboard has a lot of junk, even salt from chips and pretzels, sugar from sticky fingers, etc. Spilling even distilled water on your keyboard dissolves all of that and makes the water conductive. Luckily some better laptops have channels (drip holes) for water to drain without affecting the board, but relying on bad conductivity of distilled wated in real-life scenarios is really not safe :)
- bruce511 3y ago
  I considered digressing into this in my post, but while completely true, I concluded its also irrelevant to the point being discussed. Even tap water has sufficient contaminants to make it an excellent conductor. Outside of very clean, very lab, conditions, water conducts really well. But your point is a nice aside, and I'm glad you brought it up. Incidentally -drinking- pure distilled water tastes funny.
  - kadoban 3y ago
    Plus even if you use distilled water, it'll probably find something to disolve a bit of if you keep in on your electronics for long and then it'll conduct a lot better.
- somat 3y ago

davidhyde 3y ago

Distilled water does not conduct electricity. It is the dissolved ions in the water that allow electricity to conduct. You may be able to clean the PI to such a level that nothing dissolves into the water when it is submerged. https://techiescientist.com/does-distilled-water-conduct-electricity/ https://techiescientist.com/does-distilled-water-conduct-ele...

analog31 3y ago
Getting it that clean is hard. There's stuff like residual flux under the ball grid arrays and other surface mount components.
- namibj 3y ago
  AFAIK electrolysis will force you to utilize a scrubbing system anyways once you've got current passing through the water. But getting conductivity acceptably low is much less demanding than getting it this extremely low. E.g. some CO2 lasers are cooled with purified water to limit the current through it.
  - analog31 3y ago
    That's true. The YAG laser I used in grad school had the flash lamp inside a water jacket, and the light went through the water.
    - namibj 3y ago
      I mean things like CW CO2 tubes running in the kV range and being immersed in water with exposed electrodes.
lbourdages 3y ago
Even ultrapure water conducts electricity. It says right here [1] that its resistivity is 1.82×10^9 Ohm * m. This is a pet peeve of mine. We get told of conductors and insulators in school, but it doesn't work like that. Pretty much everything except a perfect vacuum conducts electricity. It's just that some materials conduct electricity so poorly that it can be rounded off to 0 in most circumstances, but there can still be measurable current flow. [1] https://en.wikipedia.org/wiki/Electrical_resistivity_and_conductivity?wprov=sfti1#Resistivity_and_conductivity_of_various_materials https://en.wikipedia.org/wiki/Electrical_resistivity_and_con...
- bongodongobob 3y ago
  Ok, sure but 1.8 billion ohms puts you in insulator territory. Same ballpark as rubber or glass. So no, you shouldn't really consider distilled water a conductor.
  - namibj 3y ago
    It's actually quite conductive when you'd try to exploit it's breakdown strength as coolant and insulation for high voltage power electronics.
- murderfs 3y ago
  A perfect vacuum conducts electricity as well: https://en.wikipedia.org/wiki/Schwinger_limit https://en.wikipedia.org/wiki/Schwinger_limit

FLT8 3y ago

Pure (eg. Distilled) water isn't a very good conductor at all. It's only when you add contaminant ions that it starts to conduct electricity in any meaningful sense. Most people's experience with water rapidly destroying electronics is probably with highly ionised water such as sea water or water in the washing machine which has washing powder added. Of course, it's worth pointing out in this case that as per the comments HZO claim they used water straight from the tap, so it's probably still an impressive enough achievement. I'm curious how they went about sealing the external connectors (usb, hdmi), because surely those would need to be exposed and with the voltage present would act as points of corrosion. The pins on the Pi connectors are quite tightly spaced too. Maybe the AC nature of most of the signals helps there?

ajsnigrutin 3y ago
Electronic are dirty, your keyboard has a lot of junk, even salt from chips and pretzels, sugar from sticky fingers, etc. Spilling even distilled water on your keyboard dissolves all of that and makes the water conductive. Luckily some better laptops have channels (drip holes) for water to drain without affecting the board, but relying on bad conductivity of distilled wated in real-life scenarios is really not safe :)
bruce511 3y ago
I considered digressing into this in my post, but while completely true, I concluded its also irrelevant to the point being discussed. Even tap water has sufficient contaminants to make it an excellent conductor. Outside of very clean, very lab, conditions, water conducts really well. But your point is a nice aside, and I'm glad you brought it up. Incidentally -drinking- pure distilled water tastes funny.
- kadoban 3y ago
  Plus even if you use distilled water, it'll probably find something to disolve a bit of if you keep in on your electronics for long and then it'll conduct a lot better.
somat 3y ago