Marine Wire

Building my pontoon duck boat blind/ walleye fishing boat. The pontoon will be in the water in the summer months and in and out in the fall.

How important is it to use marine wire?

and with a 2 battery system (12volt) does anyone have a diagrahm of wiring the engine, alt, ignition conections?

thanks

Mark

 

You will get a lot of different advice on marine wire. I like to use marine but there are more boats out there without marine wire than those that use it. The main points of marine wire are that it is tinned and the jacket is chemical and heat resistant. Both are important but I have had boats without and they did fine.

You don't say whether the boat is inboard or outboard. If outboard, the wiring is self contained in the manufacturers set up and can be completely separate from the second battery. the simplest system ties the negative posts of both batteries together permanently and has a single pole on-off switch to connect the house battery in parallel to the starting battery for charging.

If you have an outboard and email me, I can send you a diagram of this simple system as well as on-off-both battery connections with or without solar cells.

 

Marine wire is fine strand which has less resistance. Whatever you do, don't use house wire.

 

Thank Tom,

I sure take your news as very good. I couldn't see putting Marine wire through out this boat. The pontoon is a special setup. We have a vw engine attached to an Alpha I gen 2 stern drive for shallow water use. So I will need run the charging system off the Alt of the Vw engine. The battries (2) will be some 10 feet from the Alt. and most of the switching is another 8 feet on the helm. I am thinking of running the trolling motor, and some flood lighting off 1 bat, and the engine gauges and starter off the other bat. If you have any diagrahms that are simple and what is needed to run both battries off the one Alt on the engine, it would be a big help. I have wired many homes, but this 12volt stuff is giving me a headache.lol.

Wire size is a big concern for me.

Mark

 

Theres is house wire and there is house wire.

The marine stuff (if you can get it) is in my opinion great for one job but its all red and black with poor white sheath.

Fine muti core without tinning is what I have used. Its not house wire but its not marine iether.

All Ive seen in Marine specs is one size only, but then the shops don't stock others or there isnt any. If no one is buying it then they wont stock it.

For instance what would you use to feed an LED indicator? and then what would you use for starter feed. Cant get Marine in that or can you?

 

Around here there are all kinds and sizes of marine wire available. I think you can get adequate service out of non tinned wire and better service out of marine wire. It kind of depends just how reliable and bulletproof you want to make it.

Personally, I use damn good marine wire and solder and shrinkwrap everything. I only want to do it once if at all possible. I think Tom makes a good point that there are more boats running around without it than with it. But I suppose the failure rate might be a little higher. In short you pay your money and take your chances. I'd like to see that wiring diagram too if Tom could be persuaded to post it.

 

Fresh Water or Salt??

This would be the decider for me..

Regular THW type wire (untinned) [Often labeled "machine tool wire"] has a double abrasion-resistant jacket that works well.

But in salt environment if there are exposed plain copper strands eventually there is some corrosion. And if the jacket is damaged and the strands are exposed to salt splash, I've seen serious corrosion on some boats after a few years.

My freshwater boat with off-the-electrical-supply-house-shelf THW or THWN is fine after 30 years...

 

Who decides what is marine wire and what isn't? If you pay a ridiculously high price anything ordinary becomes "marine".
There is commercial wire and there is mil. spec. wire. The latter is very hard to handle because it has a very tough double sheath. Its application is not limited to military objects, the aviation industry is probably the largest consumer. I would not recommend it for amateur use because it is difficult to strip without special tools and has no advantage over commercial wire unless it is used in combination with mil.spec. connectors and terminals.

Stranded wire can be tinned without being '"marine". Most Asian main cords for computers use tinned wire.

Much more important is using the proper size, based on the currents to be expected and the cable length.

http://www.boatdesign.net/forums/on.../simple-wiring-diagram-small-craft-27778.html

 

CDK. If you are an engineer you should know who decides what is marine and what is not. There are specifications on wire for different applications. Sometimes they overlap.

 

If we were discussing paint, sealant or alloys marine specs make sense. For many other items it doesn't.
I have dark blue towels on board. Marine blue....

 

TY CDK'

I printed your diagraham and it is a little much for my application. It did give me some ideas, but I was wondering if you had a less complex drawing. We are only putting this on a 20 foot pontoon.

Mark

 

No, I have nothing simpler. But you could adapt it by eradicating everything you do not need. For a pontoon, that probably means there will be not much left.

 

If you are using a VW engine, the wiring diagram is on any mechanical manual. The battery wiring is included in a marine battery switch.

 

Are you saying a Battery Switch or Battery Isolator? Or are they the same?

Mark

 

I agree with CDK. Most of the 'marine' wires is only marine because the label says so.

The things to consider has been mentioned before. Use tinned wire, it oxidizes less than copper wire. The 'mil' wire had it's insulation melted to the conductor so there is no place for moisture to penetrate the insulation.

One other thing often not considered when wiring is done is the current carrying capability of the wire. Mostly the green oxidation you find in older wiring is too much current or a poor connection that causes excessive current for a relative small conductive area.

I would in any boat use tinned mufti stranded copper wire that can handle the current comfortably, then use an insulation media like conformal coating to seal all open wiring. Even hair spray works !

Insulation does not matter much, you do not need a special type insulation like the mil wires. Normal PVC insulation is fine if you shield it from the sun with a sleeve or some cover, otherwise it may become brittle over time. Other than that you won't have problems.

Battery switches or battery isolators are exactly the same thing. It is only a high current capable relay, and to be fancy gets called a solenoid switch. You should design your circuitry so they are normally in the off position, the excitement coil can draw a bit of current and will use unnecessary power. I replaced some of them on my Yamaha's trim and tilt with el cheapo ones from a car spares shop and they look as good as the originals at 20 times the price.