+ Reply to Thread
Results 1 to 15 of 27

Thread: All those wires inside my mast gotta go!

Hybrid View

  1. #1
    Join Date
    Sep 2001
    Location
    Santa Cruz, California
    Posts
    461

    Question All those wires inside my mast gotta go!

    The saga continues:

    Now that the mast is down, the old paint is stripped off and the aluminium is polished, the mast base block has been removed, and new chainplates are on order, I have time to evaluate a new problem. A small part of the lower end of my VHF Radio antenna is corroded. This was hidden by rigging tape, until I decided to remove the tape. My VHF antenna runs continuously from the mast head down through the deck to connector inside of the cabin. This seems like a good design, since the connector can be removed by a simple un-screwing and can be easily shoved up through the deck if the mast is un-stepped. I just did this.

    However, the coaxial cable just above the deck flexes at least twice a day to an extreme entent as a result of lowering the mast during the tabernacle operation. So it appears that over time the wire failed where it flexed. Corrosion is evident in discoloration of the exposed copper coaxial wire sheeth. It does not appear that the copper wire sheeth in theg coaxial cable was tinned.

    So the best thing to do is probably to pull a new coxalial cable through the mast, but here is the problem:

    The coaxial cable enters the mast a few inches above the mast base block It is met on the opposite side by four electrical wires. A black and white pair run about ten feet up the mast to the steaming light, and an orage and white pair never emerge from the mast. The coaxial cable and all four wires are bundled inside of a series of taped foam tubes that look very much like the foam tubes that you put around household water pipes in cold climates to keep them from freezing, except that the foam in my mast looks like it might be blue in color.

    Hmmm: Is this an original Pearson installation, or someone else's bright idea? I can't pull the coaxial cable without pulling the four electric wires with it. I have ascertained that the orange and white wires don't run as far as the mast head, and the coaxial cable in the vacninty of the main halyard sheeve is not encased in foam.

    It is my guess that the foam tubes run up as far as the spreaders.

    The possibility that that orange and white wires may run into the spreader tubes is somewhat disconcerting, becasue that means those wires might not pull easily. There are not spreader lights, and no opening in theh mast that might have once been used as exit ports for those wires.

    With the foam tubes, you don't have good visibility up the mast, even with a flashlight, but I can make out what appears to be a solid tube running between the spreaders. This could be an illusion. It might only be the aforementioned wires, or it could actually be an aluminum tube, which functions as an integral part of the spreader support system. I thought that removing one of the spreaders would be a good idea so that I could see what happens to that orange and white wire pair before I try to pull the wires, but alas, I would have to destroy the ss screws to remove them. The nuts are loose enough, but the screws seem to be immovable.

    1. So has anyone found foam bundled wires in their masts?

    2. Has anyone pulled the wire in your mast and replaced it?

    3. What materials and techniques did you use to pull your new wires either up or down the mast. Since I am have this foam to deal with, and I am not planning to remove the mast head, it seems easier to pull the wires down and out and down and in, rather than up and out and up and in.

    4. How did you protect your new wires from chaffing and your ears from the ringing of wire against aluminum at future anchorages. Encasing the wires in rubber hose has been suggested to me. It would have to be soft rubber hose however.
    Scott

  2. #2
    Join Date
    Sep 2001
    Location
    Northern MN
    Posts
    1,100
    Scott,
    Foam? Well that's a new idea. Did it work in keeping the mast wiring Quiet? Don Casey in This Old Boat recomended/suggested using aluminum pop-rivets to fasten lengths of PVC pipe to the inside of the mast to form a wire chase. Something needs to be done to minimize that annoying 'ding' at anchor.
    Why is it you don't want to pull the masthead off? Seem like an ideal time to do it and it would give you a better look inside the big stick. But to answere your questions-no, not yet, undecided, undecided.

  3. #3
    Join Date
    Sep 2001
    Location
    San Rafael, CA
    Posts
    3,621
    'Lo Tony,
    Congrats on getting to the mast.
    The foam pipe insulation was invented long after Pearson put the mast on the boat. My research (and I have reams of it) shows that it is the most popular method of silencing and protecting wires in the mast. Cheap, easy to install. Another method is to use nylon wire ties and leave them long so they provide a spring=like cushion in the mast.

    Imagining what I will do, but if you are forthcoming I will copy what you come up with, I would probably go to the masthead with wire in foam, and to the spreaders with the other set of wires in their own foam tubes. Stop the foam short of the mast bass with a positive tie and taping and form a loop of all wires and cable befor they exit from the mast.

    I've thought a little about that chaffing or bending problem. I thought (correct me if I'm wrong) that the exit of the wires from the side of the mast could be upwards of a foot above the maststep. Be arranged in a soft loop befor entering the deck to the junction box below. The idea, of course, is to give the wires more scope to turn, and not bend.

    I've been convinced ('Understanding Boat Wiring', John C. Payne) that #12 should be used for these long electric runs. The wires would be bundled with a self amalgamating rubber tape as they exit the mast and enter the gland in the coach roof. Seems to me it would be an impressive loop of stuff, and not likely to stress the wire at all.


    The spreader tube is there of course to keep the thrubolt from squeezing the mast where all the work is consentrated, spreader sockets and the four lower shroud tabs. It is installed from outside into holes that just fit the tube. Since it is hopefully unlikely that the mast will be worked on again for an age, I will replace all fastenings. I know that pvc chase is considered highend but couldn't it be argued that it increases weight and holes in the mast and probably more dissimilar metal in the rivets? I think the simpler way is best: all foam, all ties, or a combo.

    Remember to include a pull string for the future. How about nylon snap line of different colors, one to the spreaders, and one to the top. As for rewiring while the mast is horizontal, how about a plumbers snake to get it all started???

  4. #4
    Join Date
    Sep 2001
    Location
    Orinda, California
    Posts
    2,311
    When we pulled the wires from A76's mast in '86, there was nothing in the mast but wires When we replaced all the wires, we tried using a block of foam a few feet up from the base to keep the wires in place, but it eventually came dislodged and the wires now "clang" with every swell.

    Those other wires? Maybe someone installed a spreader light that's now gone?

  5. #5
    Join Date
    Nov 2002
    Location
    Lutherville, Maryland (near Baltimore)
    Posts
    197
    Three wire-ties with their tales sticking in three different directions every 18 inches silenced my mast. That includes VHF line to the top, a pair of wires for the anchor light and a pair for the steaming light. We laid it out on the ground then fished it in one run with an ancient electrician's snake collectively owned at the boatyard. I think I found that in Good Old Boat magazine. The local boatyard folklore says that foam holds moisture inside the mast and eventually adds weight in addition to adding to the corrosion load. The tie-wraps work fine and don't cost much.

    Your tabernacle system sounds like a necessary evil that will be hardest on the VHF line. You might consider putting RF connectors in on either side of the section that takes the most wear and tear. That way you can just disconnect the worn wire and put in a new section. Lots of connectors don't help your signal but if done well don't hurt is as much as a total signal failure someday when you need the radio. Don't tell Uncle Sam but that's what a lot of us did in the army on field radio set-ups with wire sections that consistently wore out from being set up and taken down. We just cut out the beat up section, got four connectors and two barrel splices and patched in a good piece of wire. It carried traffic just fine. We made up a patch or two and were never off the air for long because of worn wire. If you assemble and solder them carefully you won't experience much signal loss and gain some security.

  6. #6
    Join Date
    Sep 2001
    Location
    San Rafael, CA
    Posts
    3,621
    me again...
    SkiperJer, interesting advice.
    For the electrically challenged a drawing would help a lot.

    I am thinking that a connection system that would allow the mast to be EASILY disconnected for whatever reason would be a good thing. That is aside from lowering and raising 'on the run.' I was hoping there was in the marine market a waterproof junction box that would be placed over the wire thru cabin fitting that would allow efficient disconnect. There might be two glands under such a box. One to get the coaxial cable inside and there have an even more protected junction. But it doesn't exist, yet, does it? Are there any O-ring coax barrel fittings? There are, but not weather or salt proof we can use on deck?

    A strong ondeck junction box would be better to make waterproof with rubber goop or gasket replacement than wires going direct thru the deck. In a perfect world wouldn't it be a good thing if the mast could be taken down by the skipper on a regular basis? That is, all mast wires would disconnect in the junction box on deck. I can think that at haul out for bottom paint work that if the mast was already horizontal when arriving at the yard maintenance wouldn't be a problem, and we'ld save the mast pulling charge.

    How do we set up for the (near)perfect disconnect or just connecting for that matter ON deck. Need help visualizing, designing. Thanks
    Last edited by ebb; 09-28-2004 at 11:49 AM.

  7. #7
    Join Date
    May 2002
    Location
    Manchester, MA
    Posts
    151
    Ah yes...Mast wiring....I teach Marine Electronics for our local Power Squadron. (A great source of good info). The material I have says that code and ABYC standards call for minimum wire size of 16 ga stranded. I have not seen any recommendations for minimums in the mast. 12 ga makes sense.

    I have seen 2 suggestions but have tried neither. The first was to buy the longest heaviest wire ties you can find and then use 3 at a time to make a spider every few feet. In other words, tie them so the ends are about 120 deg. around all the wires in the mast. This assumes you can drop all your wiring and then pull it back in the mast with the spiders in place. The second is a variation on the foam suggestion. Buy the foam split tubes that are used to insulate pipe runs in cold places. Wire tie them in place and slide them up as far you cana nd keep placing on the wires until you can't get them to slide up any further,

    I replaced the wiring for my steaming/deck lamps last year. I used tri-plex cable in the mast but did not try either method. I am thinking of trying the tubes. I used a snake to pull the cable into the mast and that was fiarly simple. I had to use some light gauge wire to pull wire up through the compression post.
    Last edited by John; 09-28-2004 at 05:44 PM.
    John G.
    Valhalla
    Commander No 287

+ Reply to Thread

Similar Threads

  1. STRONGBACK DISCUSSION etc.
    By Tony G in forum Technical
    Replies: 89
    Last Post: 09-10-2021, 09:39 AM
  2. Dropping the mast by hand
    By epiphany in forum Technical
    Replies: 30
    Last Post: 11-22-2006, 06:29 PM
  3. Tabernacle Operation
    By Scott Galloway in forum Technical
    Replies: 17
    Last Post: 09-04-2003, 08:56 PM

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts