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Waterproof wire connection

Discussion in 'Do It Yourself - DIY' started by vitaly, Oct 20, 2017.

  1. bada3003

    bada3003 Solo Diver

    # of Dives: 200 - 499
    Location: Indiana
    234
    40
    28
    It's likely to be too stiff and a potential breaking point.
     
  2. bada3003

    bada3003 Solo Diver

    # of Dives: 200 - 499
    Location: Indiana
    234
    40
    28
    Off ebay. :)

    Three cables I've bought:
    General Cable/Carol 13003 18/3C Carolprene SVO 90C/300V Flexible Power Cord/40ft
    Carol 02722 16/2C 16 awg/2 Cond Carolprene SOOW 600V Power Cable Cord USA /20ft
    Carol 01310 18/2C 18 awg/2 Cond Carolprene SJOOW 300V Power Cable Cord USA /20ft
    Search for them on ebay and you'll find others perhaps closer to your needs. 20ft should cost less than $20.

    Check for gauge, power spec, no. of strands, and grade (SJOOW, SOOW, etc.). Your existing cable should have the specs inscribed on the sleeve. If not, or not legible, then check the power specs of your light and order accordingly. I used these cables for DIY mods to dive lights, drysuit heated undergarments, and DPV external power connections so it's more varied.
     
  3. spoolin01

    spoolin01 Solo Diver

    # of Dives: 500 - 999
    Location: SF Bay Area, CA
    1,559
    240
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    I've had good luck with the durability of liquid electrical tape - a liquid vinyl product. Haven't used it under water, but it sure looks like it should be watertight. There are liquid rubber products as well.
     
  4. JohnnyC

    JohnnyC PADI Pro

    # of Dives: I'm a Fish!
    Location: United States
    3,374
    3,734
    113
    You can generally get a few feet of the right cable (see bada3003's post above) at the Homeless Despot or similar hardware store. It's nothing special.

    As for repair, 3M Scotchcast is designed for underwater use. Get the small size though, the standard size will put a 1" diameter waterproof splice 6" long. Solder and heat shrink the wires, then cover the whole thing with Scotchcast. It's similar to liquid e-tape, but it's a 2-part flexible jacket.

    The problem with adhesive heat shrink is that it can contain porosity in the glue which may be a path for water ingress.
     
  5. vitaly

    vitaly Angel Fish

    # of Dives: 500 - 999
    Location: SF Bay Area
    48
    12
    8
    I tried liquid electrical tape with heat shrink tube and it didn't work well underwater. Adhesive heat shrink tube seems works better so far.
     
  6. spoolin01

    spoolin01 Solo Diver

    # of Dives: 500 - 999
    Location: SF Bay Area, CA
    1,559
    240
    63
    That looks like interesting stuff. Is it waterproof? The product description says it's porous for breathability.

    The liquid tape is just a flexible coating, what didn't work?
     
  7. vitaly

    vitaly Angel Fish

    # of Dives: 500 - 999
    Location: SF Bay Area
    48
    12
    8
    I used a liquid tape to isolate wire connections and make a seal over the whole cable. Above it I put a regular heat shrink tube. It leaked after submerging to ~70'
     
  8. JohnnyC

    JohnnyC PADI Pro

    # of Dives: I'm a Fish!
    Location: United States
    3,374
    3,734
    113
    Scotchcast is definitely waterproof. When I was in Dubai we used it for all of the cable splices that live inside a 2.7 million liter pool. They do fine in a highly chlorinated environment.
     
  9. spoolin01

    spoolin01 Solo Diver

    # of Dives: 500 - 999
    Location: SF Bay Area, CA
    1,559
    240
    63
    There seem to be a number of 3M products with Scotchcast in the name. The Scotchcast Plus cast (medical casts) tape comes in a variety of widths, and is stated to be both breathable and water resistant, which may or may not seem contradictory, depending on definitions. They also make a Scotchcast splice for high voltage wet conditions, which appears to be a wrap inside a hard sheath, filled with hardening urethane. They also sell epoxy based coating and potting resin for electronics, under that name.
     

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