Waterproofing Coaxial Connectors

For a great tutorial on waterproofing coaxial connectors, check out this post by Paul, AE5JU, over at K9ZW’s blog. I didn’t use Scotch 130C Coax Seal like he does since by the time I discovered its existence I was out of time to acquire it for this project. Next time!

[Update: After the helpful comments I received on this from VE3WDM and others at amateurradio.com, I’ve ordered some coax seal and plan to finish the job as soon as it arrives. What I’ve done here is better than nothing — certainly good enough until I can get the good stuff — but it doesn’t afford long-term protection.]

[Update: When I went to put on the coax seal, I discovered my nice pretty electrical tape already coming apart after less than two weeks! Use coax seal! Another thing I’ve learned about is “Magic Tape,” the self-amalgamating silicone tape you can easily find even at stores like Target and Walgreens. Some hams have told me it works great to put over the coax seal.]

What I did do was wrap the connectors with teflon plumber’s tape, then covered it with black 3M electrical tape. The teflon tape is intended simply to keep adhesive from gumming up the connector. I put several layers of electrical tape down and made sure to wrap the last layer up, i.e. toward the sky, so that the turns are stacked like shingles on a house with their seams pointed downward. Here’s a slideshow:

Click to view slideshow.

Todd Mitchell, NØIP, is a regular contributor to AmateurRadio.com and writes from Minnesota, USA. He can be contacted at [email protected].

4 Responses to “Waterproofing Coaxial Connectors”

  • Mike VE3WDM:

    What I find that works good on my out door antenna connections is 3M self amalgamating tape. It’s very flexible and seems when pulled tight gets into all the little areas.

  • Sid, 5N0SID:

    Electrical insulation tape is not a long term answer as the tape is not UV protected/stable and not that good at remaining taped up in an outside environment. You will find that the tape will harden up and go brittle and fail or simple uncoil. Far better is to use as Mike has said to use 3M’s self amalgamating tape or like others use UV stable heat shrink sleeving (yes you can get sleeving large enough to cover cable and connectors)to cover the connectors and then simple tape up the ends of the heat shrink sleeving over the connectors.

  • Cliff, KU4GW:

    I use some coax sealer I picked up at the Shelby, NC Hamfest. It is a soft pliable substance much like a clay that you can shape and mold to fit anything to waterproof it. I don’t remember what it’s called other than Coax Sealant, but it works very well. After wrapping the PL-259’s with it I then taped over it with black electrical tape and then a layer of duct tape on top of that.It doesn’t harden, but remains soft and pliable. Very 73!

  • Todd Mitchell, NØIP:

    I’m glad I posted this and got your comments! I’ve placed an order and will upgrade the weatherproofing on these connections.

    Thank you very much for the advice, gentlemen.

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