> Reviewed a bit of history of this thread to see if it was covered because I wanted to ask what pbryant has 30 feet over his head when sailing at night.
I have red-over-green lights conforming to COLREGs Rule 25(c) at the top of my mast (with conventional navigation lights down on deck). It's a rare configuration in these parts - but all the USCG licensed mariners have memorized: "Red over green -- sailing machine." Out in the Pacific, it's the big boats that worry me the most. I want there to be no ambiguity that I am a sailing vessel with a mast that might ding their prop as it passes through the blades.
Tinned wire is a must around salt water. Bare copper dissolves around seawater. I've repaired electronics on board vessels where, after stripping a wire, I discovered there was no copper left inside. And salt air will creep up unsealed insulation corroding bare copper a significant length inside the insulation. Tin plating isn't eternal, but it lasts much longer.
My procedure for making a splice is:
1) Make a Western Union splice (see graphic). This is the recommended method NASA uses. I've added to it the step of using a sealant. The splice will be as strong as the unspliced wire. You can read more here. If you are working with stranded wire, apply a thin coating of solder to the strands after twisting them together. This will prevent the strands from unroving when the splice is made.
2) Solder. I use 60/40 tin/lead with rosin flux core (never use acid core solders). Kester makes the best solder. Lead fumes are very bad for you. Solder only in adequate ventilation and avoid inhaling any of the fumes (the lead can boil on a hot iron releasing lead fumes that are easily absorbed if inhaled). If you inhale much lead you'll be as dumb as I am. Tin - with no lead - solder doesn't flow well, but it is safer. Use a soldering iron - not a gun. A good iron has a lot of mass in the tip that won't rapidly cool when it is applied to the wire joint. A gun will run too hot, will violently boil the solder, char the rosin core, contribute to oxidizing the wire and solder, and damage the insulation.
3) Remove any visible rosin (light brown to black in color), which you will only see if you used an inferior brand of solder. Remnant rosin can be mildly corrosive. Rosin is soluble in alcohol, ether, benzene and chloroform. Only alcohol is safe to inhale. Use isopropyl alcohol and a toothbrush.
4) Coat exposed conductor liberally with silicone or 3M 5200. Glob it on good.
5) Slide good quality (not Radioshack / Fry's) heat-activated-adhesive heat shrink tubing over the joint. Make sure there is an ample amount of heatshrink to cover the joint and insulation on both sides of the joint. I use Raychem heatshrink.
6) Use a heat gun (not a lighter or you'll burn the insulation) to shrink the tubing. If you used enough silicone/5200, it will ooze out both sides of the tubing when you shrink it.
I avoid like the plague all crimp-on solderless junctions. The action of crimping stresses the wire causing it to have very little flex (fatigue) life remaining. The connection depends on the metal material forming the crimp maintaining a state of compression - which gradually fades. Most of the factory crimped-on terminal lugs on my Ariel had relaxed to the point that the wires could be rotated inside the lugs. Water vapor/salt intrudes into the non-airtight junction and it eventually corrodes away. If there's substantial current flowing through it, it then gets hot and accelerates the corrosion: power dissipated as heat = current squared times resistance. The resistance rises with increasing corrosion, causing more power to be dissipated. Any junction that's a solderless crimp-on is a little ticking timebomb waiting to fail on the day you find yourself being clobbered by a ruff seastate.
If you are going to make wire junctions on a boat that last, you need to know how to solder. There's plenty of instructional material on line.
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