Tinned Wire Myth Busted?

[richandlori]

The June 2008 issue of Practical Sailor has a question and answer that seem to say that people paying a price premium for so called "Marine Grade tinned wire" are basically throwing their money into the bilge! They say that the use of Marine Grade Tinned Wire IS NOT and has NEVER been a requirement of the ABYC standards and claim it's all a great marketing hype for the makers of this high prices wire. They stress it's the terminals not the wire that are prone to corrosion, which actually is something I have personally seen when removing the 30yr old non-tinned wire from THIRD DAY to be replaced with high price Tinned Wire, as per the recommendations of my Marine Surveyor, who noted that the wire was not up to ABYC standards and needed to be replaced in my purchase survey!

So...why didn't someone tell me this before I blew over a $1000 on "Marine Grade Tinned Wire"?

Is Practical Sailor off base here…or have they exposed yet another boat myth that seem to go something like this:

“everyone knows that (bla…bla…bla..insert rumor here) is best, I wouldn’t go to sea or take my family out on a boat without (bla…bla…bla)”

Damn....

[atzserv]

I bought the tinned wire for my anchor and autopilot additions. While doing the work I wondered the same thing.

When I added the perko A B Both switch they recommended using the liquid electrical tape on the connections. This makes sense. If you seal the wire connections completely I would think you have created a barrier against corrosion.

Gary

[bastonjock]

rich,i have always thought that using crimps and wd40 would cut down on the corrosion,whilst cable may need to be replaced after 30 years due to breakdown on the insulation etc,if the old non tinned stuff functioned well for 30 years then why do we need tinned wire?.

is vaseline and rubber bo remake the terminations a better alternative? what about heatshrink to seal of the ends?if the corrosion is a problem that only effects the tails of the cabling then why not just loop the end terminations thus allowing enough extra cable to reterminate at a later day if required.

some cable salesman somewhere has sold this idea to a Naval architect

[James V]

Interesting. I have removed non-tined from a 30 yr old boat, (16 gauge extension cord) and it was limp and rotted through.

Due to the constant viberation, no solid and fine wire. No stuff for regular household wiring.

For me, I am going to stick with the tined.

[bastonjock]

james i think that you will find that all copper conductors "work harden"
vibration will eventually destroy all copper conductors regardless if they are tinned or not.

id like to see 30 year old tinned copper wire sitting next to 30 year old non tinned copper wire

ive seen 25 year old copper conductors that were in great shape despite being in a salt water enviroment,for me as long as you can seal the ends of the cable then water will not ingress up the sheathing

[James V]

Yes, so would I but they would have to be under the same conditions. the Boat that I pulled the wire out or was a coastal cruising boat of 30 years and was in the cabin top feeding some fans and lights. Not much chance of water getting into but who knows.

A agree with sealing the ends with liquid electrical tape.

[tangentair]

I just used the liquid electric tape to seal a leaking "submergable" tail light fixture and it worked quite well. I have used heat shrink tubing many times but I do not think it makes a water proof seal like the liquid electric tape. A combination of a coat or two of the liquid tape to seal things and then a covering of the heat shrink tubing for general protection/insulation and finish is probabily best - also might be overkill if you are doing a lot of wiring work.

[hart]

I just ran the antenna wire for my VHF up the mast. I also used that liquid electrical tape stuff, then shrinkwrapped over it. We'll see how well it works. I left a few extra inches at the top and bottom to redo the connectors as needed - no matter what you do Mother Nature always wins in the end, it's just a matter of how long it takes her.

[cuisto]

hart,
dont know if you are a realist, pessimist or just resigned.

no matter what you do Mother Nature always wins in the end, it's just a matter of how long it takes her.

[noahvale]

I'm an electrician with 35 years of experience.
Copper wire will tarnish faster than tinned wire. Tin will tarnish as well, but not as fast. Silver plated wire is good too, but it tarnishes as well. Only thing that won't tarnish is gold plated wire. But then if the gold plating is nicked, you can even have problems with it. In any wiring installation, the places it fails are the connection points. This is especially true with marine wiring.
Copper only wire will work fine if moisture never gets under the insulation. Typical low voltage wire for boats and cars does not have very good insulation, and moisture can penetrate to the copper in time. Building wire has better insulation. I use THHN or TFFN wire. That is the standard wire that is pulled in conduit in building construction. It has a clear vinyl layer over the insulation. It's rated for resistance to oil and water.

But the main consideration is how do you keep the moisture out of the wire at the connection points. When I say moisture, I'm talking about air. As mentioned above, the Star Bite brand Liquid Electrical Tape works great. I use several coats allowing dry time between each.

[Paul S]

our old powerboat had copper untinned wire, I used untinned wire for adding stuff. Every time I made a repair to the wire, it was only tarnished up about .25-.5 inch then the wire from there was pristine, nice and shiny.

Like the PS article, it was a very successful marketing campaign! I don't think you NEED tinned wire, but if you have it, use it! I got a lot of wire from http://www.bestboatwire.com/ that was a great price and tinned.

[tangentair]

...... that was a great price and tinned.

Paul
I just checked the website and those are pretty good prices - thanks I am playing with lighting and I can play a lot cheaper there than at WM.

[Don T]

Hello,
There are more free electrons on the surface of copper wire. Low ox wire is formed in an oxygen free environment and has lower resistance per foot than regular wire. Hence more current flows at the surface than the interior of the wire. That's why stranded wire handles more current than solid. Tinned wire will not suffer the loss of current handling that non tinned will when it oxidizes. Also it will have less electrolysis. All this adds up to heat and failure if conditions are not perfect. How many times are conditions perfect on a boat? One nick of the insulation or heat build up hardening and cracking the insulation over time = accelerated failure.

[Paul S]

Hello,
There are more free electrons on the surface of copper wire. Low ox wire is formed in an oxygen free environment and has lower resistance per foot than regular wire. Hence more current flows at the surface than the interior of the wire. That's why stranded wire handles more current than solid. Tinned wire will not suffer the loss of current handling that non tinned will when it oxidizes. Also it will have less electrolysis. All this adds up to heat and failure if conditions are not perfect. How many times are conditions perfect on a boat? One nick of the insulation or heat build up hardening and cracking the insulation over time = accelerated failure.

No doubt, but I , on my old power boat (an apparently PS in their research) found that the oxidization seems to only go in a fraction of an inch under the insulation. Can't say I have ever experienced wire failue to that degree. No doubt it happens..

tinned wire, according to the article, is not an ABYC standard.

I think tinned wire is a good thing and I use it, but never found regular wire a problem, if installed properly

[bastonjock]

ive run the odd wire or two myself,in an offshore enviroment(North sea oil and gas platforms) i have never run tinned wire,i have however sealed a lot of cable ends off and used crimps for end terminations