(Moisture-proof) Alternative to open-type terminal strips

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(Moisture-proof) Alternative to open-type terminal strips --KWKloeber 14:18, 9 May 2015 (PDT)

I'm not generally a fan of terminal strips in the marine environment -- IF I can avoid them, I do. HOWEVER, if I can't, I use them judiciously -- in the proper locations (e.g., not an open terminal strip, in an engine compartment or bilge, hanging by a thread, no physical protection, wire/cable support/strain relief, etc.)

THAT said, I have a half-dozen terminal strips for mast wiring to TV/RF to masthead instrument cables. BUT they are mounted in moisture-tight boxes with moisture-tight wire entries.

I made my own setups with 4" x 4" x 2" Carleton (top) or Cantex (bottom) PVC junction boxes (from big-box building supply/online/Amazon etc.)
They have no openings for conduit or threaded blanks -- just a totally solid case w/ a gasketed cover, and mounting ears so they don't need to be compromised with a thru-case fastener hole.

I tried several ways to get a moisture tight wire entry, but found this method was the best: Barb.png

  • Get appropriate-size nylon male npt x hose barb adapters -- Grainger carries many sizes -- so I got a selection of several size npt/barb combinations -- up to 3/8" npt and 3/8" barb.
  • Drill & tap the box side for whichever nylon barb your conductor or coax cable will snugly pass thru (I typically use one barb per large wire pass-thru and combine multiple smaller conductors thru a single barb.) Dremel off excess threads so it sits flush with, not protruding much into, the inside of the box.
  • Screw in the barb, pass your cable or conductor thru, seal the wire entry w/ adhesive heat shrink tubing (AHST) around the hose barb end. Voila` - a moisture-tight connection.
  • Where you have multiple conductors thru a barb, tighten a small (4" flavor) zip-tie near the end of the AHST to mush the adhesive into the voids between the separate wires.
  • Mount a standard or euro type terminal strip to the inside box cover (w/ thru-cover, countersunk, flat-head, s/s machine screws/nylock nuts.) It's easy (even with fat fingers) to wire up the term strip with it on the cover vs. recessed into the box, and you can bury excess wire cable in the box to be able to pull the cover out and away to easily work on the strip.

Those boxes also come in 6" size, and there are many similar inexpensive, gasketed solid boxes online in rectangular/round/whatnot configurations. Some w/ and some w/o mounting ears.