Re-wiring box construction spar

[N Wilkens]

Another posting refarding my rig:

I am refinishing 2 wood spars. This process has been more "invasive" than originally planned and so I am going ahead and re-wiring for instruments, antena, deck lights, navigation lights, etc.

The masts are both laid-up box construction and have a hollow core through which current wiring runs to the head of each spar. Near the top of the mainmast the wire comes out of the side of the mast. It appears that a wood scarf has been installed here to allow additional pulling purchase (?) of the wire.

My question is this:
How do I remove this scarf and replace it? What kind of glue/epoxy should I use to rebed the scarf?

As with my other post, any suggestions or observations are welcome and will be considered at great length since I have never done this before.

-N

[Dan McCosh]

It's kind of tough to get a picture of what you are looking at. I would guess that the scarf is the solid tip of the mast, and that is why the wiring exits there. You probably don't want to disturb it.

[Bruce Hooke]

One tip from my experience -- unrestrained wires inside a mast will bang back and forth as the boat rocks at anchor. This is really noisy in an aluminum mast and can be really annoying if you are trying to sleep. I'm not sure if would be an issue in a wood mast. My solution was to tie balled up bits of newspaper to a string every 5 feet or so and pull same up into the mast -- a pretty crude solution but it worked. Non-moisture absorbing foam might be a better solution, especially in a wood mast where something that holds water could be a problem.

[Hughman]

Originally posted by Bruce Hooke:
One tip from my experience -- unrestrained wires inside a mast will bang back and forth as the boat rocks at anchor. This is really noisy in an aluminum mast and can be really annoying if you are trying to sleep. I'm not sure if would be an issue in a wood mast. My solution was to tie balled up bits of newspaper to a string every 5 feet or so and pull same up into the mast -- a pretty crude solution but it worked. Non-moisture absorbing foam might be a better solution, especially in a wood mast where something that holds water could be a problem.

Styrofoam peanuts is easier, just make sure you get the old indestructible ones, not the cornstarch biodegradable ones.

Fill the mast completely after you chase the wires.

[Hughman]

Originally posted by N Wilkens:
My question is this:
How do I remove this scarf and replace it? -N

I wouldn't disassemble a wooden mast for wiring replacement.

Pull one of the old wires out, (from the base, most likely) making sure you have securely attached TWO strong strings to it. These will be used to pull new wires. Remember, the mast might be solid at the spreaders and partners, with a small hole for the wiring, which might scrape your chase strings apart. Repeat with the others. I would leave an extra string in place for future use.

Good luck.

[N Wilkens]

Thanks for your input. I'll try w/o removing the existing (10" x 3/4") scarf and see if I can get all the cables through.

-N

[Stiletto]

Another option for stopping the wires rattling in the mast is to fit three cable ties around the cable, leaving the ends sticking out at 60 deg. to each other. Every foot or so should do it.

[gaffman]

Rather than tying string to the wire to pull it through, I think I might soldier the next wire right on and pull that through. You don't have to worry about the knot slipping on the wire.

[Nicholas Carey]

A couple weeks ago, I was talking to someone in the boatyard where PIRATE's been getting her finish paint put on. They were refinishing/rewiring a rather large -- 60+ foot -- box section hollow mast.

At some point in the spar's past, someone had done something fairly brilliant: they'd run thinwall PVC conduit the length of the mast (inside), through which all the various wires were snaked. I don't know if it was an afterthought, or if it was designed in, but it certainly made snaking new wire easy enough.

[N Wilkens]

Originally posted by Nicholas Carey:
A couple weeks ago, I was talking to someone in the boatyard where PIRATE's been getting her finish paint put on. They were refinishing/rewiring a rather large -- 60+ foot -- box section hollow mast.

At some point in the spar's past, someone had done something fairly brilliant: they'd run thinwall PVC conduit the length of the mast (inside), through which all the various wires were snaked. I don't know if it was an afterthought, or if it was designed in, but it certainly made snaking new wire easy enough.

That's a great idea! Unfortunately I have to deal with what I have. My main mast is about 10' shy of 60'and could have benefitted from this kind of arrangement. Did you happen to notice how/where the wires exitted the mast at top/bottom?

Thanks,

N

[Dave R]

gaffman's suggestion to solder the new wires to the old before pulling is an excelent suggestion. Solder the wires end to end and put a nice, fair tape covering on the joint.

While you're at it, pull an extra wire or a piece of strong line in case you want to add something else aloft later.