corroded wiring

HoffaLives · #1 (**permalink**) 05-04-2007

I'm in the process of yanking my seacocks and I notice that there is
copper wiring
attaching all the bronze thru-hulls, presumably so they all have the same
galvanic potential.
But the wiring is very corroded, as are the surfaces of the thru-hulls, and I imagine the
resistance would be
so high as to nullify any conductivity. The wires are held on by stainless hose
clamps. Should
these connections be routinely cleaned? Any problem with soldering directly to the bronze thru-hull?
And I'm wondering if there isn't something that should be put on the connections andwires to keep them from deteriorating.

sailingdog · #2 (**permalink**) 05-04-2007

Is the copper wire just plain copper... if that is the case, then that is probably why it is so corroded. Soldering the wire to the thru-hull isn't generally recommended, as you want a mechanical connection, that you can remove in an emergency. The wire, really has to be marine grade pre-tinned wire, to reduce the problems with corrosion. It sounds like they used plain copper wire... which is a bad idea on a boat.

HoffaLives · #3 (**permalink**) 05-05-2007

Yeah, just plain single-strand copper wire. I guess I have to yank it. This is on a CS 36 and I'm surprised - doesn't look factory at all and I would expect more from this calibre of boat.

I found a large seacock on the exhaust, which is above the waterline -is this normal? I would think thru-hulls above WL wouldn't need them. A PO with too much money perhaps?

sailingdog · #4 (**permalink**) 05-05-2007

If it is solid untinned copper wire, then that is really a bad idea on a boat.

The solid wire will fatigue much more quickly than the finely stranded marine grade wire would, and being untinned means it will also corrode much more quickly. If it was to protect the throughhulls from corrosion...then it probably stopped working, and I would highly recommend you inspect said throughhulls for galvanic corrosion. If the boat is out of the water, scratch the thru-hulls and if they appear at all pinkish, it is very likely that some corrosion has taken place and that they are in need of replacement.

gc1111 · #5 (**permalink**) 05-05-2007

Bonding seacocks is controversial. There are arguments both ways. The point is that many boats have survived quite well without the bonding. So even if your bonding failed, it does not necessarily mean damage to the seacocks.
The traditional way to check the seacocks is, WITH THE BOAT OUT OF THE WATER, take a hammer and give them a good whack. If they shatter, they need to be replaced! If not they are probably good for another year.

About seacocks on above the water fittings. You want the seacock. This is a case where a gate valve is acceptable. My boat (center cockpit) has the exhaust coming out almost midships and a couple of feet above the water. It has a gate valve that is operated once a year for winter storage. It keeps bugs, small rodents, etc out! Also, the exhaust can be buried in rough conditions. If there is a problem with the exhaust system you might want to be able to close it off.

HoffaLives · #6 (**permalink**) 05-05-2007

I found an article from Practical Sailor describing various grounding systems aboard and they state that bronze thru-hulls should not be bonded together as stray marine currents can then attack them. While it may be controversial, I think I'll just pull that stuff out. The wiring and plumbing is enough of a mess as it is.

And I am replacing the seacocks because someone replaced the original bronze ones with ABS plastic (not Marelon) valves.