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Water and Electronics, a match made in hell ...

Discussion in 'Amateur Radio News' started by VK6FLAB, Aug 4, 2018.

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  1. KI4AX

    KI4AX Ham Member QRZ Page

    When I was in College Chemistry class we performed an experiment which showed that pure water does not conduct electricity.

    Basically, we made a circuit containing a battery, a light bulb, and a cup of water as a switch. With pure water in the cup the light bulb would not light up - the circuit would not conduct. But, when we added a bit of impurities like salt, to the water, the light bulb would light up.

    According to the results of the experiment pure water will NOT conduct electricity. There has to be some impurity in the water, causing Ions to form, before water will conduct.

    Dan KI4AX
     
  2. KI7HSB

    KI7HSB XML Subscriber QRZ Page

    Water WILL NOT harm electronics. However, Energizing said electronics in water will ruin your day.

    I remember back in the early 80's when I was an electronics tech...

    We had these test machines we were using at a semiconductor manufacturing plant. The channel timing boards (we called them "Pin Electronics boards") had to be calibrated regularly and sometimes they were a bastard because the signals wouldn't stay still. I reasoned that the problem was invisible dirt, so my solution to the problem was to take the boards (4 per machine) to the sink in the back of the shop and using mild hand soap, a long soft bristle brush and lots of warm water, scrub the ever loving bejeebers out of them. After a thorough rinse, I tossed them into the burn-in ovens to dry for a couple hours. After that, they calibrated right up and the timing circuits were rock steady.

    One day, the suck-up-know-it-all-master-brown-nosing-gonna-be-the-boss-someday tech on the crew saw me doing this and he about had a stroke. Said I had just destroyed a $10,000 PE board. I just said "No... it'll be fine". He thought the dumb farm kid was just plain lucky that the things still worked after I did that. Well, about a year later, Mr. suckup got selected to go to a training class at the test equipment manufacturer in California.

    When he came back he told me "I owe you an apology."
    "For what?" I asked.
    "Remember how I thought you were crazy for washing the PE boards?"
    "Yeah."
    "Well, that is exactly what the manufacturer taught us to do to them when they become unstable and can't be calibrated."

    I might have taken the opportunity to rub it in his nose that the farm kid wasn't such an idiot after all, but I was pragmatic... All I said was "Cool, now you have a new tool you can use too."

    Of course, this was all indoor equipment... Keeping rainwater out of live circuits is important.
     
    VK6APZ and KI4AX like this.
  3. K4ECD

    K4ECD Premium Subscriber QRZ Page

    The internet. That place where fact and fiction collide in a single sentence.

    "perfect insulator" is relative, but that part is correct - pure water or distilled water is an excellent insulator.
    "will not boil" - that is just wrong. Of course it boils: at 100 Celsius or 212 Fahrenheit at normal atmospheric pressure.
     
    W4RAV and AJ4LN like this.
  4. W0DGH

    W0DGH Ham Member QRZ Page

    Forget about rice to dry stuff unless that is all you can find. Go to your Wally-Mart or equivalent and buy a tub or two of the closet dehumidifier desiccant and bury your electronic device in it. That has saved many cell phones around here. After you are through put the desiccant in your oven for a couple of hours at about 200*f and dry it back out. Store it in a ziplock bag for future use.
     
    AJ4LN likes this.
  5. W4KDN

    W4KDN Ham Member QRZ Page

    An interesting experiment but could have been taken further by increasing the voltage until it did conduct. So, the findings would be "pure water" is a POOR conductor of electricity. Air will conduct electricity......if there is enough electricity to make it happen.
     
  6. VA3ECO

    VA3ECO Ham Member QRZ Page

    I don't know if I can post a you Tube link, but here goes:

    It's an interesting video about the use of Corrosion X.
    I personally have never tried it, but apparently it has quite a following.
    -Chris VA3ECO
     
  7. W1YW

    W1YW Ham Member QRZ Page

    Huh!

    That's totally wrong. Of COURSE it boils....

    Go look up the physics of phase changes.

    What you MEAN to say is that approaching the phase transition, pure water approximates a metastable state which is offset by an impurity or a change to the potential well. In others words, any type of motion. Random motion in the water water itself will also set it off.

    Boiling chips help offset that metastable state, for example.
     
  8. KI7HSB

    KI7HSB XML Subscriber QRZ Page

    Given enough potential, electrical energy can pass through nearly anything, but what you are referring to is the breakdown of the dielectric properties, which isn't really the same thing as conduction. During the breakdown of the dielectric, a bridge of ions becomes the conductor allowing the energy to pass through the insulator.

    Water has a dielectric strength of 65-70kV/mm. Air, (at atm pressure and flat electrodes) around 3kV/mm. Once past that point, electrical power will "conduct" over the ion bridge that forms between the source and sink.
     
    Last edited: Aug 17, 2018

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