Electrolysis potential ? Unorthodox use of Rub-Rail

**home made tunnel** · 05-03-2016, 07:34 AM

Hey guys -
So while installing my amplifiers and speakers for the boat, I had an idea from my automotive background... Instead of running a ground wire through the whole boat harness.... Can I just use the Aluminum Rub Rail as a ground return? Would that potentially cause electrolysis on the rub rail?

My rubrail is nut & bolted in, not riveted. I can put an electrical lug on the inside of the boat up front under the dash, and use the rub rail to travel to the rear, back to the battery, with another jumper.

Anyone else done something like this? Can you think of any issues? The rub rail doesn't sit in the water, which is what normally causes electrolysis, right? Boat doesn't sit in water, always trailered. Rarely will ever be in Salt.

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**Mark75H** · 05-03-2016, 01:05 PM

Speaker doesn't work with just one wire; no real reason not to use paired conductors.

**home made tunnel** · 05-03-2016, 01:44 PM

Originally Posted by Mark75H

Speaker doesn't work with just one wire; no real reason not to use paired conductors.

The amplifier Power wires - I have 2 amps going up front. 1 for speakers, 1 for the sub. If I can get away with only running 2 power wires, I'd prefer that, and just use the Rubrail for the ground return to battery in the back.

**David - WI** · 05-03-2016, 01:52 PM

I would be more worried about how good the electrical connection between the bolts and the rubrail is... even with stainless bolts in aluminum "The corrosion of the base metal is marginally increased by the fastener." https://www.fastenal.com/content/fed...0Corrosion.pdf
It can be frustrating chasing a bad ground when something doesn't work right.

**home made tunnel** · 05-03-2016, 02:20 PM

David, That's a really good read. I wonder if putting the direct current of an 800 watt amp grounding through the stainless bolt would exacerbate the corrosion.
I guess if I lose the ground, I can always move 6" to the next fastener on the rubrail haha.

I love science threads like this. Anyone else have experience?

**pointer** · 05-04-2016, 04:23 PM

800 Watt DC amp and your thinking of using the rub rail as ground?

Likely not a good idea. No science involved.

pointer

**olboatman** · 05-04-2016, 04:34 PM

I have always believed that if ya gonna run 1 wire....why not run 2? I even run ground wires for automotive and trailer electrical connections and have zero problems.

Gary

**rock** · 05-04-2016, 05:25 PM

Many things are grounded to the frame. In my shop I use the conduit as ground and right or wrong it works. I would do some testing with a voltmeter and see if it will zero out. I do believe a separate ground wire is best but don't see why the aluminum rail won't work.

Rock