Tinned Copper Wire In Freshwater Environment

[kevintblack]

This is question is more informational. I've been doing some rewiring and have been using tinned copper wire. I am in a 100% freshwater environment in the Great Lakes. <br /><br />My dad is a metalurgical engineer and specializes in copper and brass alloys. His specialty is residential wiring and he really doesn't have any boating experience. <br /><br />He asked why I was using tinned wire. He said tinned wire in a marine environment made perfect sense because of the corrosion issues, but didn't see the need for it in a freshwater environment.<br /><br />I didn't really have an answer for him. I assumed that even freshwater systems may have some levels of salts that could cause excessive corrosion. I also assumed there may be issues with the pH of the water as well.<br /><br />I'd be interested in hearing anyones thoughts on this.

 

[peterc38]

Re: Tinned Copper Wire In Freshwater Environment

My humble opinion would be that even in freshwater, the wire is exposed to the elements, i.e. oxygen and water that it would not see in "residential wiring" service conditions. I would think bare copper can oxidize relatively quickly, and potentially cause some failures, even in a freshwater environment. I have a 14 ft Lund that I only use in freshwater. I'm no expert, but I just wired some electronics in it and I used all marine grade tinned wire. I felt the extra expense was justified for the increased reliability and longevity. For the same reasons, I used waterproof fuse holders for the inline fuses, as opposed to an automotive grade fuse holder. Hey, its a boat, things get wet.

 

[18rabbit]

Re: Tinned Copper Wire In Freshwater Environment

I’m thinking along the same line as Peter. It’s not the water that is the problem; it’s all the stuff that can be dissolved in water that causes the corrosion. Saltwater is not necessarily the only enemy of bare copper wire.<br /><br />Also, if you think you may ever sell your boat, a potential buyer that has saltwater use in mind, and may pass on your boat if it has bare copper wiring.<br /><br />Btw, does your dad have an opinion on crimping vs. soldering for the connections on your boat?<br />

 

[kevintblack]

Re: Tinned Copper Wire In Freshwater Environment

I've seen the melee that results from the crimp vs solder issue in the historical posts. Not sure I want to be the cause of another one. <br /><br />On the wiring I'm replacing the prior owner used a combination of electrical tape and wire caps (didn't see a ceiling fan anywhere on the boat). <br /><br />I haven't seen any postings on the crimp vs solder vs wirecaps debate. Maybe this will start one.

 

[18rabbit]

Re: Tinned Copper Wire In Freshwater Environment

I recall something about wire caps/wire nuts being specifically prohibited, but I don’t remember the reference.

 

[kevintblack]

Re: Tinned Copper Wire In Freshwater Environment

I was just kidding about the wirecap debate. I was a little shocked to find them stuffed under the deck.<br /><br />I just bought this boat and I'm finding all kinds of 'interesting' repairs made over the years. I've found duct tape, bondo, and a whole lot of electrical tape. I've decided to start at the bow and work by way back, replacing any hack jobs I run accross. I'm guessing I will be craeating a lot of posts.<br /><br />I appreciate the help! There are a lot of really smart people on this site. A lot smarter than me!

 

[jlinder]

Re: Tinned Copper Wire In Freshwater Environment

For marine use you cannot use solder as the only mechanical support for the connection. You must use crimp. The debate is whether or not to add solder to the crimp connection.<br /><br />(I am on the side of not soldering. I do not believe it adds anything but can weaken the metal on the crimp terminal and make it weaker.)<br /><br />You should also get some heat shrink tubing to put over the connection to seal it. Preferably the type with adhesive on the inside that will form a completely air tight connection.<br /><br />Solder only, wire nuts, tape, etc are big no-no's.<br /><br />Also (and I hope this goes without saying), stranded wire, marine tinned preferred, and support the wire fairly often. Keep in mind that boats vibrate a lot. If it can shake free it will.

 

[JB]

Re: Tinned Copper Wire In Freshwater Environment

On the crimp vs crimp and solder, no comment. He didn't ask about that.<br /><br />If household wiring were subjected to an (even freshwater) marine environment codes would require tinned wire.<br /><br />'Nuff said?

 

[Paul Moir]

Re: Tinned Copper Wire In Freshwater Environment

Tinned wire isn't a requirement of the ABYC, but it is a good idea.

 

[willamettejeff]

Re: Tinned Copper Wire In Freshwater Environment

BB, like yours my new-to-me boat's wiring was a mess and very unreliable. Even found some of those wire nuts too, so I decided on a complete rewire. Also like you, I went back and forth for a couple of weeks deciding on whether to spend the extra money on tinned wire as my boat would more than likely only be used in fresh water. In the end I chose to use the tinned wire as the whole point of rewiring the boat in the first place was to make the boat as reliable as possible so that it could just be enjoyed without worrying about it. Also, heatshrinked all connections although only used the adhesive lined stuff on butt connections and in the primary battery wiring circuits. Used only marine-grade tinned connectors as well.

 

[Realgun]

Re: Tinned Copper Wire In Freshwater Environment

"Twist on connectors, i.e., wire nuts, shall not be used.” 11.16.3.6.

Good thing you removing those wire nuts!<br /><br />Somne of the boat builders here in New Mexico build their wire looms from non-tinned wire. I was a bit surprised to see these 500+ Hp 27 foot or bigger and real expensive boats using the cheap wire but the guy said that there was no salt water for at least a 1000 miles and it has not been an issue.<br /><br />I was tring to find a local source of tinned wire and failed.

 

[ron7000]

Re: Tinned Copper Wire In Freshwater Environment

OEM wiring is not tinned wire, that should tell you something.<br /><br />The only place you'll have a problem, with any wire, is where it is exposed which is at the connector. Tinned wire will corrode and fail just the same. Just do the connections good.<br /><br />the funny thing is, tinned copper wire (ie the ancor crap) is great for soldering... since it is already tinned.

 

[jlinder]

Re: Tinned Copper Wire In Freshwater Environment

I suspect that good use of adhesive heat shrink to seal the connections will help you more than tinned wire. But that is just my suspicion.

 

[kevintblack]

Re: Tinned Copper Wire In Freshwater Environment

Thanks. It is interesting to hear the different perspectives. <br /><br />I'll continue to use the tinned wire, though I wish I could find a better local source. The boat shop I go to is always about 2 feet short of what I need and their connector section is a little thin too. I've been sticking to the internet, but that doesn't work real well when you're in the middle of something.<br /> <br />I agree with Jack L though. I think even the best wire will fail if your connections are bad.

 

[peterc38]

Re: Tinned Copper Wire In Freshwater Environment

"OEM wiring is not tinned wire, that should tell you something."<br /><br />Actually, the upper tier boat manufacturers do use tinned wire, That should tell you something!

 

[Realgun]

Re: Tinned Copper Wire In Freshwater Environment

Actually, the upper tier boat manufacturers do use tinned wire, That should tell you something!

Wow I am an upper tier MFG on my bayliner.

 

[Buttanic]

Re: Tinned Copper Wire In Freshwater Environment

Originally posted by Realgun:<br />

Actually, the upper tier boat manufacturers do use tinned wire, That should tell you something!

Wow I am an upper tier MFG on my bayliner.

Several years ago I did a rewire on a 31 Bertram and I don't recall finding any tinned wire. I still have some of it that I removed. I guess Bertram is not an upper tier manufacturer

 

[byacey]

Re: Tinned Copper Wire In Freshwater Environment

As far as crimping and soldering I may offer my opinion. I am an electronics technician, and for my own purposes have done wiring on cars, boats, trailers and other wiring exposed to the great outdoors. A crimped connection will work for a while, until moisture and electrolytic action between the dissimilar metals of the wire and connector cuase corrosion resulting in a high resistance connection. Once you have resistance and current, you get heat. now you have corrosion, heat and more oxidation taking place due to the heat when current flows and the process snowballs over time. If you crimp AND solder, you have a mechanically strong connection to begin with. Soldering this connection creates an even better, low resistance connection plus the added protection to the joint due to the inert properties of the lead/tin solder. A connection done in this manner will outlast a crimped connection many times over. Be sure to only use rosin flux solder for radio or electronic work. Acid core plumbing solder will only create more corrosion. Tinned wire can be had from any Electronic industrial wire cable supplier for a very reasonable cost. 18/2 guage wire is about $80.00 US per 1000 feet.

 

[jlinder]

Re: Tinned Copper Wire In Freshwater Environment

byacey,<br /><br />I suggest you read the number of posts that have been made regarding crimp vs. crimp&solder. This is no where as straight forward as you think.<br /><br />I am of the camp that says not to solder. A crimp connection will last a very long time. In fact, I raised the question in a post a while back asking for people with experince on old connections that had been done either way. The only reply I got with experience was with a navy boat with 20+ year connections that was still in perfect shape.<br /><br />When you solder a crimp connection you heat the crimp and possibly weaken them. While not definative, there is a lot of evidence to indicate this.<br /><br />Crimp connections are very simple to do if you get a good crimper. Solder connections are easy to do incorrectly.<br /><br />A proper connection will be crimped and have have heat shrink applied. Preferably heat shrink with adhesive. I have opened 10 year old connections with this heat shrink that were airtight and looked like they were new.<br /><br />As for 18/2 guage wire, that is not necessarily a good idea. You need to take into account the current and the length of the wire.<br /><br />I would not use 18 guage for anything over 7.5 amps, and only if the length is short enough to keep the voltage drop low. Some people consider 3% the maximum, some use 10%.<br /><br />The question is not that simple

 

[byacey]

Re: Tinned Copper Wire In Freshwater Environment

You are correct, the wire guage must be chosen for the current load, I just used that guage as an example of price. A crimp connection if kept dry in a low humidity situation will as you say, last for years. Get it wet every once in a while and you will have problems before long. Some copper type crimp connectors may become annealed from soldering, but that shouldn't affect their strength as far as a connection. Wires should be properly supported and tied in place to eliminate the connector bearing the wire weight. This is common practice in my industry.