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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. VK6FLAB

    VK6FLAB Ham Member QRZ Page

    foundations-of-amateur-radio_300.jpg
    Foundations of Amateur Radio

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

    It's been raining around here for a while now. Not in the order of 40 days and 40 nights, but significant. Mind you, I have lived in a place where it rained every day for 57 days, but I digress.

    Water, plenty of it and often in all the wrong places.

    Being a radio amateur you come across water in many aspects of the hobby, sometimes it comes in handy, like lubricating your throat while you're calling CQ, or as a ground plane for an antenna, other times, not so much, like when it enters the shack and causes the black smoke to escape from your pride and joy.

    As I said, I'm no stranger to rain and in my travels I've encountered plenty of it. I managed to travel around Australia for a couple of years and I took with me a two-way satellite dish with sensitive electronics attached. Living in Australia I planned for dry. This place is dry. Often very much so, but as it turns out, dry doesn't mean without humidity, storms, rain or in one case hail.

    These experiences told me a little about protecting electronics from the weather.

    I should add a disclaimer here, I'm not a certified weatherman, nor am I certified in waterproofing, water ingress, or any other guarantee. So, if you do as I say and it breaks, you get to keep both halves. That said, I have some thoughts on the matter and I wouldn't be me if I didn't share them.

    Water is generally everywhere. It gets into everything and it's one of those silent killers. Electronics and water rarely mix, unless you submerge the electronics in mineral spirits, or if you seal your electronics in circuit board lacquer. Even then, there are few guarantees.

    The best you can hope for, in my experience, is to plan for failure, hope for success.

    Finding where water gets in is often the hardest part of keeping it out. Sealing off your electronics from the world in a waterproof anything will trap heat, which in turn will cause condensation, which will ultimately cause rust and destruction of your priceless electronics.

    Giving your stuff time to acclimatise is a very good idea. For example, if you have a radio stored in your garage and you bring it indoors, leave it there for several hours, if not overnight. Unless you live in Alaska with an in-floor heater to prevent your engine block from freezing, your garage is cold, your home is warm, the combination causes condensation. Alternatively, if your garage is hot, and your home air-conditioned, the reverse is true and condensation will still happen.

    Water has a habit of finding its way into anything, encouraged by gravity. That means that a length of coax, run into your wall will attract a stream of water along the coax, straight into the connector and into your wall, or between the core and the braid, or into your radio, or some other undesirable place. If you create a low point before the connector, like a drip-loop, a place where water would have to go up before it can do damage, you'll likely solve the issue, but don't discard the effects of wind which can cause water to go uphill.

    Connectors are magnets for water. Most connections in use in amateur radio have little or no waterproof rating. There are special waterproof connectors about and you may consider using those, but alternatives like self-amalgamating or rubber tape, which you wind tightly around a connection and in doing so, stretches and glues itself together to keep the water out. These tapes are generally not stable in the ultraviolet of the sun, so you may have to wrap that sealed connector in another layer of tape, plumbing or electrical tape is one solution.

    Based on the experience from national coax installations, the way to do this is with three windings of rubber tape, followed by two of plumbing tape. Think of up as towards the weather and down as away from the weather and make the windings like this:

    Wind the rubber tape three times around the connector, up, then down, then up again.

    Seal this from the sun with two windings of plumbing tape, down and then back up towards the weather.

    For endurance, add a cable-tie to keep the tape in place when the glue eventually fails. This will ensure that water always runs away from the connector.

    The way to remember this, for a positive result, there are three ups and two downs.

    If you ever get your coax wet, that is, the end, be prepared to cut off a length to protect your gear. Coax rot is real and is essentially the rusting of the braid, the shield or the core and it spells bad news for your gear.

    Operating portable is a whole other subject in relation to weather, but the same principles apply. Keep the temperature stable, keep the water out, protect from rain ingress along the coax and you'll likely be able to have a good time and come home without any damage to your gear.

    There is a persistent idea that rice can help you dry electronics. While it does have some effect, it's slow and by the time it's removed the water, the damage will already have been done. Air drying is much more effective. Use a fan, keep it running and you'll have a better chance of rescuing a drowned circuit.

    As for electricity and water, they don't mix, they can kill and you should know better.

    I'm Onno VK6FLAB

    To listen to the podcast, visit the website: http://podcasts.itmaze.com.au/foundations/ and scroll to the bottom for the latest episode. You can also use your podcast tool of choice and search for my callsign, VK6FLAB, or you can read the book, look for my callsign on your local Amazon store, or visit my author page: http://amazon.com/author/owh

    If you'd like to participate in discussion about the podcast or about amateur radio, you can visit the Facebook group: https://www.facebook.com/groups/foundations.itmaze

    Feel free to get in touch directly via email: onno@itmaze.com.au, or follow on twitter: @VK6FLAB (http://twitter.com/vk6flab/)

    If you'd like to join the weekly net for new and returning amateurs, check out the details at http://ftroop.vk6.net, the net runs every week on Saturday, from 00:00 to 01:00 UTC on Echolink, IRLP, AllStar Link and 2m FM via various repeaters.
     
    W4MMR, EA3GNH, W3MT and 3 others like this.
  2. NU4R

    NU4R XML Subscriber QRZ Page

    If "air" will dry my seeming perpetually soaking wet golden retriever, it'll surely dry soaked electronics! Though, I've NEVER tried drying her in rice.

    All kidding aside...good stuff Onno! 73!
     
  3. AB2YC

    AB2YC Guest QRZ Page

    I have washed out with water many pieces of electronics gear over the years.
    Wash it out then put it with a fan blowing on it (or over furnace register etc.).

    Water can be your best friend when cleaning electronics out, it's
    far gentler than many other solvents and pure water is residue free.
     
    K4IIN, AJ4LN and KI7HSB like this.
  4. KA9JLM

    KA9JLM Ham Member QRZ Page

    Water is life.

    Just need the correct type of water.
     
  5. K7YVO

    K7YVO Ham Member QRZ Page

    FYI...pure water is a perfect insulator and will not boil
     
  6. K9CTB

    K9CTB Ham Member QRZ Page

    When I was in naval electronics school <garble> years ago, I had this great (to me at least) civilian instructor who beat it into me that "dirt is death" in electronic equipment. I later learned that, so is water .... and the combination of the two is an even quicker death. I never forgot the lesson. Now my ham gear is pristine on the inside, compared to my shack floor which needs sweeping even as I write this!! :)
     
  7. K9CTB

    K9CTB Ham Member QRZ Page

    Once that pure water touches a wire or circuit board, it becomes an instant conductor. Try it yourself. On the "will not boil" part, um, just plain no. Ask any Operating Engineer for a demonstration.
     
    K7HOR and 10XSHOOTER like this.
  8. KF5UMC

    KF5UMC Ham Member QRZ Page

    DI water is used to clean "wafers' that contain many IC's prior to being cut into small pieces and placed into a chip. Water is also a wonderful thing in the right place. I also travel around the country and have found after a good rain the counterpoise or ground plane improves and my signal and reception is better with the vertical antenna. I have found through trial and error, that hanging up a dipole antenna between oak trees, with the feedline too close to the trunk of a tree will adversely affect the SWR.
     
  9. W1UO

    W1UO Ham Member QRZ Page

    Deionized pure water is a poor electrical conductor, having a resistivity of 18.2 million ohm-cm (18.2 megohm).

    When I worked at VOA, all the big transmitter tubes were water cooled, with tens of thousands of volts on the plates. No arcs, no sparks.
     
  10. G0WXU

    G0WXU Ham Member QRZ Page

    Regarding water cooling tubes (Valves). That was a point of great interest to me as a young Royal Signal operator who had the chance to look into an "E10 Transmitter" many years ago. There was this bloody great glass tube, glowing nicely with water cooling pipes connected up and warning notices for ensuring that the water supply was on at the correct pressure before transmitting. No operator safety notices were to be seen. It was presumed that you would have the sense to keep well away from Anode connection when power was running. The feeling of power, knowing that just one touch of the key would send a signal out across the world. Doing the Marconi thing. while on training at Catterick, I was located very close to one end of an E10 transmitter antenna with my 1Watt output transceiver and vertical whip antenna. I was part of a small CW net of stations around the Catterick Garrison area. We had not been on the air for very long before getting a visit from our instructors telling us to pack-up ready to move. Apparently, my CW signal was being picked up along with the E10 teleprinter signal and causing QRM on the received printer signal in Hong Kong. Work that out for QRP BCI.
     
    EA3GNH, K4IIN and KU4GW/SK2023 like this.
  11. WQ4G

    WQ4G 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
     
  12. KI7HSB

    KI7HSB Ham Member 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/SK2022 and WQ4G like this.
  13. K4ECD

    K4ECD Ham Member 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.
     
    K2NCC and AJ4LN like this.
  14. 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.
  15. 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.
     

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