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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, then 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 probably a dozen terminal strips for everything from mast light wiring to TV/RF to masthead instrument cables. BUT they are mounted in moisture-proof boxes with moisture-tight wire entries.

I made my own setups with moisture tight 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/ gasketed cover, and mounting ears so they don't need to be compromised with a thru case mounting hole.

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

  • Get appropriate-size nylon male npt x hose barb adapters -- Grainger carries many sizes -- so I got a selection of many different size npt and 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 generally use one barb per pass-thru, but sometimes combine multiple conductors thru a single barb.)
  • Screw in the adapter, pass your cable or conductor thru, apply adhesive heat shrink tubing (AHST.) . Voila`.
  • Where you have multiple conductors thru one adapter, tighten a small (4" variety) zip-tie on the end of the HST to mush the adhesive into the voids between the cables/conductors.
  • Mount the terminal strip to the inside box cover (w/ thru-cover, countersunk, flat-head, s/s machine screws and nylock nuts.) With fat fingers it's easier to wire up the strip on the cover than in the box, and you can bury enough wire/cable in the box, and pull the cover out and away to easily work on the strip later. Where it makes sense I'll Dremel off excess thread to the barb ends up nearly flush with the inside of the box.

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