Working on mast cap

[ChrisW]

I have my mast in the yard and want to do some work at the mast cap.  As you can see from the picture there is a really bad and strange hole in it.  The wire cable going through it is a coax to the VHF antenna.  It is almost completely severed.  I installed an anchor light there on a bracket that you cannot see.  The PO had no anchor light.  I bought new coax for the antenna and new cable for the anchor light that I want to run through the existing PVC conduit. 

I have a few questions:

1.  How  would you recommend I cover up or fill in that ugly hole?  I thought about finding some aluminum to either weld or fifty-two-hundred over it.  But I don't know how to weld and I don't know where I'd find a thick piece of aluminum the right size.

2. Should I use that better looking hole to run both the coax and cable for the light, and install a grommet in it?  And if I do that should I put any kind of sealant around the wires?  Or should each cable have its own hole?

3.  Would it be better to drill a new hole(s) for the two cables that is actually on the side of the mast that the conduit is on?  What exists now is a hole through in inside of the mast cap allowing the wires to go from the starboard side to the port side of the mast (the exit holes are on the port side).  I have no idea why they didn't just drill the hole through the starboard where the conduit is attached.

Thanks

[kh3412]

Perhaps you could drill a hole that removes the problem area and install a rubber plug. Then grommet the hole for the wires and seal. We use big rubber plugs on old police cars when taking all the lights and antennas off.

[Gregory M]

Or you could use something like this https://ca.binnacle.com/Electrical-Cable-&-Deck-Connectors/c58_198/p10126/Glomex-RA140-Cable-Feed-Thru-White-Nylon/product_info.html
or this https://ca.binnacle.com/Electrical-Cable-&-Deck-Connectors/c58_198/p1381/Blue-Sea-1002-Waterproof-Cable-Clam-.825-in./product_info.html
I used that type on all cables coming out of mast side, different sizes  for different cables. Easy to attach.

[KWKloeber]

Chris a couple thoughts come to my mind.

I ran both mine thru the side, less likely to get water intrusion.

Though not my preference, keeping them thru the top would probably be the easiest for you, using 1 or 2 pass throughs.

If you do cover the top it doesn't need to be really heavy aluminum, you just want to put window dressing over what's there.  You can get many oddball materials thru McMaster Carr. Probably heavy gauge alum.

You might be able to get a LARGE."well nut" to plug the ugly hole if you redrill it.

Alternatively a rubber cork, drill a hole thru it for a stainless screw to tighten it once inserted (sorta like a plastic wall anchor) experiment with the size screw. A plug w/a shoulder like a well nut would be best but unsure if you can find that at McMasterCarr.com

[scgunner]

    Chris,

      That black hole with the three screw holes is probably where the original anchor light was, looks like PO broke a couple of screws trying to remove the anchor light. The other butchered hole looks like it was done by a guy sitting in a boatswains chair with a drill who just kept drilling holes until the opening was large enough for whatever needed to be passed through it. I wouldn't be overly concerned about the cosmetics, the only way anyone can see it is to take a trip up the mast in a boatswains chair. I'd just run or install whatever you need, then seal any holes that remain, it doesn't have to be an exotic sealer, Henry's roof patch would work fine.

[sailr4]

Just redid mine.

[ChrisW]

Perhaps you could drill a hole that removes the problem area and install a rubber plug. Then grommet the hole for the wires and seal. We use big rubber plugs on old police cars when taking all the lights and antennas off.

How would one drill a hole that removes the problem area?  I assume you mean to enlargen the ugly hole to make it round so a plug can fit.  I'd be afraid to do that and am not sure how.   It seems like it would have to be a pretty big hole, and there isn't a whole lot of room there. 

BTW, my use of the word "ugly" was to distinguish between the two holes in the picture, not that I am worried about the aesthetics of it.  The only thing I am worried about is water intrusion.

[ChrisW]

Also I found that it's not easy to find the right rubber grommet that will fit the thickness of the mast cap.  I found some retailers online that can supply them in the exact specifications but they deal in large quantities.  You can't just go down to your local hardware store and pick one up, apparently.  At least that's what I've found.

[ChrisW]

Or you could use something like this https://ca.binnacle.com/Electrical-Cable-&-Deck-Connectors/c58_198/p10126/Glomex-RA140-Cable-Feed-Thru-White-Nylon/product_info.html
or this https://ca.binnacle.com/Electrical-Cable-&-Deck-Connectors/c58_198/p1381/Blue-Sea-1002-Waterproof-Cable-Clam-.825-in./product_info.html
I used that type on all cables coming out of mast side, different sizes  for different cables. Easy to attach.

I ordered the first item you mentioned. But now I am wondering how well it will hold up in the sun being that it is made of nylon.  Was it the second one you mentioned that you used?  If I were to use one of those, is there any danger of the cables chafing if the underlying hole in the aluminum is left bare?

[dfloeter]

Maybe try the Blue Sea version with a stainless cap to cover the nylon?  As to the ragged hole, I would try to drill it out with a larger bit and file/dremel the edges.

[kh3412]

To drill a bigger hole you need to backup the area with something solid to use a a guide for the hole saw. Check youtube for ideas. From the picture not sure how big the hole would need to be, but we get plugs upto at least an inch. You would need to remove the cap from the mast to have access to the other side.

[Stu Jackson]

Have you considered just covering it?  A small piece of aluminum plate, drill holes in four corners for bolts, drill & tap the four holes, seal it with Bed-It-with-Butyl tape.

[ChrisW]

Have you considered just covering it?  A small piece of aluminum plate, drill holes in four corners for bolts, drill & tap the four holes, seal it with Bed-It-with-Butyl tape.

That's what I was originally thinking. KWKloeber suggested a site where I could maybe find a piece of aluminum. Otherwise I don't know where to get a piece of aluminum plate.  I should have done that.  If I try to enlargen the hole to put a rubber stopper the hole would have to be at least 1 1/4 inch in diameter.  I don't want to do that.

I'm thinking now of just putting some plastic over it and getting it done with so I can go sailing.

[Stu Jackson]

Chris, I don't know where you live, I usually include it in my signature on this and other boating forums.

I found scrap aluminum at an iron works place in a town near me.  I do, however, live out in the country, where we still have Kubota tractor dealers and service places right out in plain sight!  Can you imagine!?!  :D

You might consider asking at an auto repair place, or ask them where they get their stuff.  Could be something close by you that you just hadn't considered.

Good luck, happy hunting.

Don't forget Maine Sail's butyl tape, it'll last forever.

[KWKloeber]

Drilling out a very ugly hole seems like a head-scratcher, but it's actually straight forward.  However, like the ugly hole for the VHF cable, you can't use a normal twist drill. 

If it's small enough draw a circle using a hole template, bottle cap, whatever works -- and round out w/ a Dremel but.  Finish up with a twist drill if you need it perfectly round (dremel it slightly undersized).

If it's large, you need a template to guide a hole saw, instead of a pilot bit to guide it.  For aluminum, a cheap steel hole works.  Bore a hole thru 3/4" pine or any wood -- doesn't much matter.

"Affix" the template over the odd hole -- clamp it, drill and screw it, even make it a long "bar" that someone else can hold in place.  Or double-stick tape and hold it.  Or gorilla tape it in place.  Or make a "hat" for over the top from three pieces screwed together held it in place with a binding strap around the mast.  Whatever works to hold the template temporarily.

Remove or retract the pilot bit in the hole saw and drill thru the template.  Depending on the material use very light pressure/med speed, or medium pressure and very slow speed -- just avoid "chatter" on the material.
The goal is just to get a groove started -- then remove the template and finish thru-drilling.