Ideas on how to plug a cable hole in cabin roof

[GWilly]

So I am running the cable from a new GPS antenna on the radar arch on my 30’ power boat down to the new AIS transponder inside the cabin. The cable end already has a PL259 connector on the end so I’ve got to drill a 3/4” hole thru the fiberglass in a semi-protected location (to be covered by a clam shell cover). The cable isn’t very big, so there’s a lot of open space around it as it passes through the 3/4” hole. My query is how do I plug that hole, or with what? Filling it with 4200 caulk seems overkill or excessive. What have any of you done in a similar situation? Thanks.

[Jd1]

It's fairly straight forward to chop off the connector, run the cable and put a new connector on. Maybe ask around your friends as to who has a soldering iron and can help you. It really is only a 5 min job.
There might even be connectors that do not require soldering - not normally recommended but since it's inside in a protected area it should be ok.

[belizesailor]

Mechanical seals make for a cleaner and serviceable seal.

https://www.defender.com/category.js...-1|328|2289986

[Suijin]

I would definitely cut a PL259 connector off and put a new one on vs. drilling a 3/4" hole. Those connectors are easy to put on. There are a zillion YT videos on how to do it.

That said, I also like the clam seals the belize pointed you to and you can get one big enough to accommodate the 3/4" hole. You can seal the cable and the hole with caulk, but the mechanical seal lasts longer and if you need to rerun/adjust the cable for any reason in future it's easy. I would use one no matter what size hole you drill.

[belizesailor]

Is deck where you plan to drill cored?

[MartinR]

There are mechanical seals available that take multiple cables, and also the connector can pass through with ease.

[GWilly]

Great suggestions! I completely overlooked the mechanical seals, so appreciate those suggestions. Previously I’ve had to run an antenna coax and I chopped off the potted connector, then attached one of the new Shakespeare connectors that doesn’t require soldering. It was okay but I wasn’t hugely impressed. I’ll look closer at the mechanical seals. Thanks everyone.

[MartinR]

Mitron Marinteknik: Sure from Sweden

[stormalong]

I agree with others that you should cut off the connector and put a new one on after threading the cable through the whole.

I do not like any of the cable seals on the market. I prefer to drill a hole that is a tight fit for the cable, countersink both top and bottom to eliminate any sharp edges and seal the cable with a bit of white silicone. It looks nicer that any cable clam I have ever seen.

To make a neat job of the silicone you can mask around the hole and around the cable leaving about a 1/4 inch reveal. Smooth the silicone with your finger and before it cures hard pull off the masking tape.

If your deck is cored you need to seal the core - whatever the core material is. The way to do this is tape the bottom of the hole. Mask around the top of the hole and fill the hole with epoxy. If the core soaks up the epoxy (good) top it off with more epoxy. Once cured redrill the hole. If you don't seal the hole you will pay a much higher price to fix it later. That was a big headache on my boat because the original builder didn't bother to seal the chain plate slots.

[HopCar]

Take a look at the Newmar CCX series of Waterproof Thru-deck fittings. They are designed to do exactly what you’re trying to do. No need to remove the fitting. They are available in several sizes for holes up to about 1-1/2”.
https://dcpoweronboard.com/waterproo...ru-dex-series/

Blue Sea Systems also makes them.
https://www.bluesea.com/products/cat...23/Cable_Clams

You can order them from my old company.
Cable Clam

[Defeverboat]

Blue sea cable covers are crap plastic uv light problems. Go with Scanstrut deck seals stainless steel from Defender or internet.

[GWilly]

To wrap this up...

Thanks to all for the comments and suggestions. I opted to go with the Scanstrut mechanical seal. I think it’ll work fine for my purposes. I like the look and ease of installation.