Tinned Marine Wire

Why care about tinned copper marine wire?

This comes down to another simple and basic argument. If there's a benefit to your wire installation and the cost is negligible then why wouldn't you take advantage of the extra protection?

Tinned copper is a process of electroplating the individual copper strands with tin so that each strand is totally encased in a thin tin layer that keeps corrosion and oxidation at bay. We've all seen what happens to bare copper when it is exposed to air and moisture. The beautiful bright shiny copper turns black and/or green with the buildup that forms on it's surface. That buildup can be scrubbed away however it's not a task you want to perform daily and it's not feasible to "scrub" each individual strand of your copper wire. 

Now, of course the argument can be made (has been made and surely will still be made in the future) about
non-tinned bare copper and how long it has lasted on a particular boat without a problem. Wow...that's great and we are all very happy for you :) Let's be honest here, it's like the argument where a person drinks and drives but has never been arrested or had an accident so it's not so bad, Right?

As far as the approved wire types for boats, only the cheapest SAE style wires are likely un-tinned. Of course there will even be some tinned version of those SAE wires which, while meeting the bare minimum standards for a wire installation on your boat lack in other areas with regard to copper conductor mass, insulation thickness, strand count and flexibility among other small issues. Most of the UL listed wire approved for boat use will be tinned copper as the cost for tin plated copper stranding is not that much more than the bare copper and the benefits extend far past just the marine environment into automotive and machine wiring where a desire to avoid corrosion is common. In fact..in this author's humble opinion, all copper wire should be tin plated to prevent corrosion just because it makes too much sense once you understand and see the difference with your own eyes. 

One of the many ironical arguments surrounding the sorts of folks who'll defend bare copper as "okay" is those same people are the ones using solder to made connections instead of crimping. Solder will adhere much better to tin plated copper strands. In fact, the correct process to dip solder bare copper stranded wire into a connector is to first dip the strands into the solder in order to tin the strands and then dip a second time to achieve better adhesion. 

So beware...and try to side on the side of logic and reason. If you're looking for a quality wire for your boat you'll likely want a tinned wire and that wire would likely be UL1426 listed Boat Cable meeting and exceeding all recommended specifications set forth by the US Coast Guard and ABYC.