Question:
As a winter project, I brought my 14 year old Jon boat into the garage to
clean, paint, and generally overhaul it. While working on it, I decided that
this would be great time to rewire all of the electrical devices, (trolling
motor, bilge pump, lights, livewell pump, depth finder, etc.) shorting the
cables and adding off/on switches. With a 12 foot Jon boat, it seems like
I'm always tripping over a wire somewhere.
So I logged onto eBay and found a very nice marine switch panel that has
several switches including a timed on/off switch for the livewell. My
question is, would it be possible with an aluminum boat, to run the
battery's ground cable directly to the boat, and then just use a few "hot"
wires to the 12 volt devices and switches, much as you'd do in an
automobile? This would eliminate running two wires to everything.
There's no high voltage, even when charging, and the aluminum should be an
excellent conductor. It would sure simplify things. Has anyone done this, or
do you think I'm missing something here that would keep this from working or
would cause it to be dangerous?
Answer:
-I don't think that you would want current running thru the hull of your
boat. Even it it were a good idea you would be relying on the rivets or weld
to be good enough to pass current. They do not use aluminum wire any more
due to bi-metal corrosion, and on existing aluminum wire you have to use a
conductive paste. Put in a pair from the panel and common ground to each
device. Don't risk life, limb, or personal safety over some extra wire.
Get the good marine wire by the way. The high strand count gives you a much
more flexible wire, and will keep it from breaking out of your crimps or
connectors.
-Solder all the connections rather than use crimp-ons and you will save
yourself a bunch of headaches as time passes.
-In the 60s and 70s a lot of mobile homes were wired with aluminum wire. It did
not work out very well due to the fact that aluminum oxidizes instantly in
contact with air and reacts with most other metals, but it was used as a
conductor.
