Moderated Discussion Areas
  ContinuousWave: Small Boat Electrical
  Wire Corrosion in Saltwater Environments

Post New Topic  Post Reply
search | FAQ | profile | register | author help

Author Topic:   Wire Corrosion in Saltwater Environments
17 bodega posted 09-05-2006 11:49 AM ET (US)   Profile for 17 bodega   Send Email to 17 bodega  
On my boat and on the 12-volt trailer wiring the wires turn almost completely black and become brittle and carbonized. I'm not sure if the cause is saltlwater corrosion or it comes from shorted or poor connections. I suspect it is from the saltwater corrosion.

Has anyone re-wired a trailer to avoid this? Does using the Anchor-brand wire avoid this alltogether?

Any advice or solutions welcomed.


JBCornwell posted 09-05-2006 12:42 PM ET (US)     Profile for JBCornwell  Send Email to JBCornwell     
Don't know about Anchor brand wire. The reason marine grade wire is tin plated is to avoid what you are getting. My guess is that you don't have marine grade wire.

Red sky at night. . .

17 bodega posted 09-05-2006 07:01 PM ET (US)     Profile for 17 bodega  Send Email to 17 bodega     
Got it, but I find it strange that the new LED trailer lights that are made to be submerged in saltwater are NOT made of the tin shielded wire, which means they would eventually suffer the same fate as the other wires. Also the EZ loader trailer is only a few years old and has the bad wire.. I guess I'm locked into re-wiring the entire trailer and probably my whole boat too.

Backlash posted 09-05-2006 07:57 PM ET (US)     Profile for Backlash  Send Email to Backlash     

I rewired my whole trailer last year and used the regular off-the-self trailer wire. The marine grade tinned wire might be better, but if you use all Ancor (or the equivalent 3M brand) butt connectors, ring terminals, etc. with the heat shrink connectors with the adhesive inside you will be fine. These connectors effectively seal the bare end of the wire which is where the corrosion starts. I have found a heat gun (like for paint stripping) works best for melting the adhesive and tubing.


17 bodega posted 09-05-2006 11:01 PM ET (US)     Profile for 17 bodega  Send Email to 17 bodega     
Thanks for the tip. I have never done the shrink tubing, and the stock plugs were not waterproof and corroded fairly fast. I am a heavy saltwater user and now that I work at a facility with a saltwater boat ramp, rust and corrosion are a major factor for me. I believe there is no way around doing a total shrink tube job on my wiring.

has some good deals on wiring supplies. Anyone have a better, less expensive source for wiring supplies?


jimh posted 09-06-2006 07:30 AM ET (US)     Profile for jimh  Send Email to jimh     
Ancor-brand wire is quality wire but it comes with quite a premium price. Any contact with water, especially saltwater, is harmful to copper wire. Intrusion of water into the copper wire must be avoided. That is the only way to suppress the corrosion.
where2 posted 09-06-2006 09:16 PM ET (US)     Profile for where2  Send Email to where2     
Another thing you can do to increase the reliability on your trailer lights is to run ground wires from the lights back to the trailer plug ground connector, rather than relying on the metal trailer frame to provide an adequate return path for the circuit.
cwolf posted 09-08-2006 12:33 PM ET (US)     Profile for cwolf  Send Email to cwolf     
17 bodega,
I felt I received fair pricing on wiring and connectors from the following eBay dealer. Sure was a lot cheaper then my local West Marine.

chopbuster posted 09-09-2006 12:11 PM ET (US)     Profile for chopbuster  Send Email to chopbuster     
Ancor products, though pricey, are a good choice for saltwater environs. I use only ancor marine grade wiring.

Salt water will "wick" into your standard wiring and leave the salt residue behind causing your problem.

edfish posted 09-17-2006 02:49 AM ET (US)     Profile for edfish  Send Email to edfish     
If you can get a hold of some Navy wire from a surplus supply you will have bullet proof wiring. The wire is stranded, although not as fine as Anchor, and is stiffer, and has "gel" inside the insulation coat. The wire is not easy to find.

Anchor is good wire and I use it often along with the heat shrinks with the sealing compound.

I also use those new waterproof wire nuts on my bait pump connections with great success. These connections are constantly in salt water and show no signs of corrosion when I change the pumps about twice a season. Almost as good as what I will let you in on next.

A little secret for your light bulbs and sockets, use Vaseline. You will be surprised how great this works.

On the electrical panels I use Vaseline or Corrosion Guard. Hoever, do not use Corrosion Guard on printed circuit boards. Use Vaseline on your fuses and sockets too. On your battery terminals too. Paint it on with a brush if you have to.

I have a 1972 21 Outrage that I fish commercially all summer and in the Winter for crab. I take a real beating in the weather and everything is in salt water or heavy spray and what I said is what I use. I have had no problems using these methods.

Be sure to use the Anchor or Navy wiring or you will get the saltwater intrusion and black wire you are describing. Dont't forget about the insulation on the wire. It is just as important as the wire. Make sure it is tough and able to take some impact and abuse. That auto wire they sell is not quite up to marine use.

Hope this helps. The Best to all. Ed T.

edfish posted 09-17-2006 02:53 AM ET (US)     Profile for edfish  Send Email to edfish     
Just thought of another use for the Vaseline, I use it on all the connections of my electronics. I just stuff the plugs full of Vaseline and squish them together. Never had a problem yet. The connections stay perfect. Also on the antennae connections. The list goes on and on.

Once again, all the best to all. Ed T.

swist posted 09-17-2006 07:25 AM ET (US)     Profile for swist  Send Email to swist     
I never found most commercially available trailer wiring accessories (lights, harnesses, etc) to be very high quality (nor the stuff the comes in most trailers to begin with!). I would not tolerate that stuff in my boat. Claims of submersibility seem to be exaggerated. As the previous posts suggest, the only way to get first-class trailer wiring is to do it yourself to marine standards.
HAPPYJIM posted 09-17-2006 09:07 AM ET (US)     Profile for HAPPYJIM  Send Email to HAPPYJIM     
I install low voltage landscape lighting in my business and always have wiring on hand. The wiring used is approved for direct burial in wet conditions. I use this low voltage wiring for my trailers whenever I have to replace the wiring . The wire is multi-strand and very flexible. It is 2 conductor and looks very much like lamp cord but heavier. The wire is #12 gauge so it is much heavier than the standard #14 or #16 normally found on trailers. Not a big deal on the short runs on trailer wiring but a bigger wire will have less voltage drop making lamps burn brighter than smaller gage wire. The insulation is heavier also which protects the conductors from bumps and scrapes.
It runs about $30 for 100 foot, enough to do 1 trailer.
It is not color coded but it has a molded tracer in one side of the insulation.
I try to solder as many connections as possible.
I use heat shrink tubing that incorporates a gel waterproofing material that oozes out both ends of the tube to seal the splice. I use the tubing on ALL splices. The tubing runs about a dollar for 2 pieces.
I use a di-electric grease that is used on low voltage lamp sockets to prevent corrosion on lamp bases and sockets when replacing burned out bulbs.
If you can keep out salt air and water from contacting the conductors of wiring, standard automotive wire will work. By using the heat shrink tube and di-electric grease where needed, trailer wiring will last much longer and will be easier to trouble shoot.
Nothing is permanent in salt water environment
17 bodega posted 09-18-2006 04:50 PM ET (US)     Profile for 17 bodega  Send Email to 17 bodega     
Great info gang.. thanks. this is just more proof that I will need to rewire my entire boat and trailer and make the proper shrink tube seals this time around. The ebay link seems good and the vaseline idea too.


Chuck Tribolet posted 09-18-2006 05:40 PM ET (US)     Profile for Chuck Tribolet  Send Email to Chuck Tribolet     
The problem with vaseline is that it melts in hot weather.
Use a good silcone dielectric grease. It will stay put.


swist posted 09-19-2006 10:47 AM ET (US)     Profile for swist  Send Email to swist     
Chuck, what's a good source for Silicone Dielectric Grease?
Chuck Tribolet posted 09-19-2006 11:01 AM ET (US)     Profile for Chuck Tribolet  Send Email to Chuck Tribolet     
Ancor part 700115, West Marine part 1201250 is an easy
source, $8.99 for a small tube (1/3 oz.)

Another option is Dow-Corning #4, McMaster-Carr p/n 1204K12,
$10.00 for a BIG tube (5.3 oz.).

I use Dow-Corning 111, just because I have it for some of my
dive gear, McMaster-Carr p/n 1204K32, $9.62 for 5.3 oz. It's
heavier bodied and REALLY stays put when wet. Good to 400F.

I wouldn't be surprised if the Ancor part was actually Dow #4.

Don't get hung up on the tube sizes. The Ancor part will
be good enough for most of us for several years.


chopbuster posted 09-19-2006 03:20 PM ET (US)     Profile for chopbuster  Send Email to chopbuster     
Try Permatex Ignition & Wire Drier and/or dielectric grease at Auto Zone cheap prices.
17 bodega posted 10-11-2006 12:03 AM ET (US)     Profile for 17 bodega  Send Email to 17 bodega     
I spoke to ancor wire on the phone today. Strange as it would be, the company is down the street from me but they only sell to distributors which is a few cities away...

They do have a part which is a 4 flat wire roll but not the trailer connector. It is ancor part #154002

the ebay store looks like a good source...It's just too bad they don't have a discounter right in my neck of the woods.


CAPRI posted 06-05-2007 04:38 AM ET (US)     Profile for CAPRI  Send Email to CAPRI     
I just bought some Self Fusing Silicone tape...can I wrap the connectors with that? Supposed to be water proof...for a ski (jet ski). I am going to use your advise for the trailer lights.. (I just got this older model & am fixing it up).
Bella con23 posted 06-05-2007 05:01 PM ET (US)     Profile for Bella con23  Send Email to Bella con23     
I have found that leaving the trailer light connector in place while backing into the water has the most detrimental effect on wiring and there connections. I have witnessed fine streams of bubbles boiling up from the trailer light connectors in salt water. This electrolysis effect turns the copper wires black and erodes the conductors and connectors alike.
17 bodega posted 06-06-2007 01:04 AM ET (US)     Profile for 17 bodega  Send Email to 17 bodega     
Yes. I curse myself when I forget to disconnect before dunking. The problem as I see it is the cheap West Marine LED tailights are junk. They use the old style cheapo copper wire and are not properly sealed. Even if you disconnect before dunking, the salt water gets in. In theory, if your seal is true and complete, there should be no ill effect from dunking with lights on. Am I correct on this Chuck? Dive lights work underwater as does lots of electric dive equipment. This equipment would be useless if the water tight seals were compromised.

CHRISWEIGHT posted 06-13-2007 08:11 PM ET (US)     Profile for CHRISWEIGHT  Send Email to CHRISWEIGHT     
black rot I believe is only a problem on DC supplies and I don't believe it to be related to salt water. however the cure seems to be tinning of the copper conductors so marine grade tcw is the only solution that can be relied upon.

regards chris

Chuck Tribolet posted 06-15-2007 11:27 PM ET (US)     Profile for Chuck Tribolet  Send Email to Chuck Tribolet     
The sealing on dive lights is an order of magnitude better
than even on expensive trailer lights. But they should be --
the really good dive lights run upwards of $1K. And they are STILL
problematic, though it's usually the fragility of the HID
bulbs. Even expensive UW cameras leak from time to time.

Yes, if you could keep the water 100% out, there wouldn't be
any corrosion (thought cold water on hot bulb might be bad).

My West Marine LED trailer lights are holding up just fine.
I do USUALLY remember to unplug them, but do forget from
time to time. There's no evidence of water intrusion (you
can usually see the condensation on the inside -- I had some
Peterson Pirahana running lights that didn't keep water out.)


17 bodega posted 06-16-2007 12:02 PM ET (US)     Profile for 17 bodega  Send Email to 17 bodega     
On my West Marine brand LED lights, many of the individual LEDs on each light have burned out. This happened on several lights that I returned to the store. I haven't been able to determine the cause so I assumed the lights were defective. I was careful to use shrink tube butt connectors, extra shrink tubing and liquid electrical tape on all the tailight connections.

mentor posted 02-24-2010 06:03 PM ET (US)     Profile for mentor  Send Email to mentor     
this is a great product we use on all our boats here. I have nothing to do with the company that makes this stuff but it is far and away the best protection ever.... great on aluminum as well
mentor posted 02-24-2010 06:04 PM ET (US)     Profile for mentor  Send Email to mentor     
forgot the web site,,, sorry

17 bodega posted 12-18-2011 07:29 PM ET (US)     Profile for 17 bodega  Send Email to 17 bodega     
I brought this topic back because:

1. It was at the top of the search "saltwater corrosion" on Jim's search function feature of the website.
2. I lost a GPS sounder/chart plotter largely due to poor care and maintenance of electrical connections in a saltwater environment.

Don't do what I did. Treat your electrical connections with dielectric grease regularly. While we are here talking about corrosion to chart plotter/sonar connections (and all electric and electronic connectors for that matter) I would like to ask about other creative ways you have retarded saltwater based corrosion on your vessel.

I have ordered a large tube of grease that Chuck referenced over five years ago above this post. The tube of grease is closer to $15 now but still a bargain.

May your boating cup runeth over this season


ericflys posted 12-19-2011 03:42 AM ET (US)     Profile for ericflys  Send Email to ericflys     
When I rewired my boat I shopped around quite a bit, and the best source I found was It is not Ancor brand, but they guarantee that its at least as good. I found their wire to be identical, and I like their heat shrink connectors better.
seahorse posted 12-19-2011 08:28 AM ET (US)     Profile for seahorse  Send Email to seahorse     

what's a good source for Silicone Dielectric Grease?

Often you will see small envelopes or tubes of dialectric grease at the counter of auto supply chain stores. If they don't have it on display, just ask.

Do not use Vasoline, not only does it melt and also attract dirt, it can affect the rubber and plastic insulation and other parts.

lizard posted 12-19-2011 10:54 AM ET (US)     Profile for lizard  Send Email to lizard     
I use dielectric gel and routinely find it in automotive stores. I had my entire boat rewired last year, bow to stern. There were a few problems (starboard bow light was out) but most of it was done to be proactive about 20+ year old wiring.

Prior owners had meddled with various wiring over the years. I have found Anchor wire to be far better than non-tinned wire and this bore out as we stripped the boat.

Post New Topic  Post Reply
Hop to:

Contact Us | RETURN to ContinuousWave Top Page

Powered by: Ultimate Bulletin Board, Freeware Version 2000
Purchase our Licensed Version- which adds many more features!
© Infopop Corporation (formerly Madrona Park, Inc.), 1998 - 2000.