Rewiring the mast; Conduit and other musings...

[sailingchefs]

Just getting ready to rewire the mast on our '87 Hunter 26.5. In searching the archives, I only found one entry about installing PVC conduit, riveted to the inner forward surface of the mast. Neat trick with a bent nail!
I have rewired the mast on an O'Day 222, so I know about using string leads and a fish tape, but want some input on conduit, since I will now have to avoid the internal hals, as well as the hardware of the shrouds and spreaders. Would it be advisable to just bundle the harness with lots of zipties and leave it at that?
Currently, there is only a steaming light with 2 wires. We are adding VHF coax, an anchor light, and upgrading the steaming light to include a foredeck light. Would it need two conduits with one only going half way up, or drill a hole in the plastic at that point? Which wires should I choose, how many strands per and what gauge? I'm thinking of running an extra pair to the steaming light in case we decide to add something else later like a horn or spreader lights. I'm also planning to leave an extra string or two to pull other wires down the road, for wind speed etc. I am planning to use marine grade wire, and would like to use one size larger than is really needed. Also planning to solder, grease, and cover the connections with heat-shrink tubing wherever possible.
I am planning to over-drill, fill, and redrill the holes through the coachtop for the connectors, so they can be properly bedded with 4200 and not leak into cabin or core. How many connectors will be needed? with how many pins? Currently there is one 4 pin connector partially/badly installed, with the anchor light addition in mind, but there will be 3 switched circuits: anchor light, steaming light, foredeck light; make it 4 with an extra. Is there an 8 pin connector I should be looking for?
On the inside, it looks like there's a removable panel on the compression post, so I'm hoping to fish all the wires through to the bilge, and aft with the original harness. Has anyone tried this? What will I find below the sole when that comes up? Should I just run new conduit on the side somewhere under the settees instead?
Many questions at once, I know, but any enlightenment from those who've done this refit will be greatly appreciated........ Thanks, Glenn and Tom

 

[Scott T-Bird]

I did this a few years ago ...

First of all, to size your wires, do the simple math based on the wattage of the lights and the lengths of run. I used Sailboat Electrics Simplified by Casey for reference. You may be able to come up with smaller guage, but I basically had nothing smaller than 16 guage. I have VHF coax, a wind instrument cable and an anchor light at the mast head, midway up I installed a combination steamer and deck light. If I'm not mistaken the deck light wanted a 14 guage because of the higher wattage.

So I ran all wires and cables in a 3/4 inch conduit (maybe it was an 1" - I don't remember) and I used zip ties to bundle. I might have left the coax alone - don't remember). The conduit is rivited to the front of the mast as you describe. I cut a hole in the conduit where the steamer/deck light is installed. Some people say that combining grounds is a no-no but I did it this way ... The anchor light ground runs to the base of the mast. The steamer and the deck light ground is combined on the fixture so I just needed a ground for that combo running to the base of the mast. I used the larger wire, so 14 guage. At the base of the mast I combined the 16 guage anchor light ground with the 14 guage combo ground and led a 12 guage ground to a 4-pin connector. 4-pin connectors are easy to deal with so it consists of 3 power leads (16 guage anchor light, 16 guage steamer light, 14 guage deck light) and one 12 guage ground. I never saw a good explanation for how to size a ground for a combination involving different lengths of run, so I assumed a combined wattage for the longest run and came up with 12 guage. It may be overkill, but it is only from the mast step to the panel so no big deal.

I have a deck step mast and the hole leading into the salon is in the mast step and very tight so all my connectors are above the step and pushed into the mast before stepping. I am not really happy with this arrangement and have made a decision to change it the next time I have my mast down. I am going to configure a way to make the connection inside the salon but haven't worked out the details yet. The problem I have is that rainwater finds it's way down the inside of the mast and thru the roof where the hole in the mast step is. It ends up on a fiberglass floor which doesn't bother me but it also seeps into other places which is a disturbing problem. I can't help you with the best way for fishing your wires to the electrical panel. Rest assured, it will not be easy and you will run into snags!

 

[BobM]

Loose wires, even zip tied into a bundle, will slap inside the mast when it is windy. A conduit is the best idea, but I don't know if I would want to drill a bunch of holes in my mast either. Perhaps a combination. Zip ties and a piece of conduit in part of the mast, say from the base to the steaming light. Chances are you can make a connection at the steaming light add at the base of the mast without drilling and riveting, leaving just the need for a couple of rivets in the middle. I wouldn't necessarily put extra wires in the mast, although it isn't a bad idea, but I DEFINITELY would leave a thin line (strong twine or something similar) in place so I can pull a wire through easily in the future.

 

[jackhartjr]

I am getting ready to do this to an Oday 22.
I plan to have the coax as well as a combination tri-color and anchor light. The coax that I am replacing has a small hole about 3 inches from the base that it goes in and comes out a couple inches below the masthead. I will drill those out a little larger and put a rubber thingy that I can't remember the name of in order to prevent the coax from chafing and rubbing a hole in the coax. For the light the wire will share the holes the coax goes in.
There is a through deck connection already near where the coax goes into the cabintop...I will simply replace it because it has had rain on it for years unprotected. I will find a cover for it for times the boat is on the trailer.
I am purchasing a deck connector, probably from West Marine that has four pins which is enough. You can find them with up to 12, there was a post I made on this a week or so back, it has a link to several.
To prevent the dreaded wire slap I will run several of the 'pool noodles' that kids use in swimming pools. I have to run them up from either end because they will stop at the spreaders.
I will also have an extra cord it there in case I decide to add something later.
Hope that helps.
I will post photos when I get done.
Jack