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andyjen 02-28-2009 03:55 PM

What guage do I use
I am wiring some new cabin lights and a car stereo system in my Catalina 22. what guage wire should I use? Do I have to use marine grade wire or can I grab some 14 or 16 guage from Walmart? Thank you from Seneca Lake NY, Andy

FarCry 02-28-2009 05:30 PM

Need more information to answer your first question. What wattage are your lights? How many are there? How long of a wire run will be needed?

Please use marine grade tinned wire if you want it to last.

Trickster 03-01-2009 01:06 AM

I have always used marine grade wire.

As FarCry said you really need to know the wattage / total amp draw on the system. Also one problem I ran into with my stereo was that it was having problems with voltage drop because the run was too long.

Deadeye 03-01-2009 01:44 AM

Short answer: unless you're trying to light it up like an operating room, I can't see a Catalina 22 having enough of a run to overload 14/2 AWG. Definitely use a tinned marine grade wire like Ancor boat cable. Marine 14 guage wire is '14 AWG' which is a slightly thicker conductor than the '14 SAE' that you'd get at wallyworld or an auto place. Additionally, the tinning on the wire keeps the copper from corroding from the ends inward.
Boat cable is handy because the positive and negative conductors are carried together in a common sheath which is really convenient for hookup, identification, and mechanical strength.

Also, the ABYC recommends yellow wire(aka 'safety wire') for the ground conductor instead of black because of the prevalence of AC systems on boats now.

The 'resources' section of the BlueSea website has tables that allow you to check your total draw against the length of the run (remember that's round-trip length) to figure maximum wire size for 10% allowable voltage drop (general) and 3% (electronics and critical equipment) but there's no escaping a bit of simple math.

Here's some reading to get you started:
Voltage Drop in Conductor - Wire Sizing Chart - Resources - Blue Sea Systems
Allowable Amperage in Conductors - Wire Sizing Chart - Resources - Blue Sea Systems
Remember too that this is for AWG wire, not SAE sizes and be sure to de-rate the wire a bit so the fuse/breaker blows long before the wire's ampacity is reached (that's your safety margin)

I'm no stereo expert, but with car stereos on boats I've found that the recommendations for speaker wiring seem meant for the comparatively shorter runs in a car - you won't regret going bigger on the power and speaker wires. My truck has 18 or 20 SAE speaker wire but the longest run is only 6'...
A 'mobile audio' forum is probably a good place to ask and they can address other stuff like noise filters and vibration damping. No offense meant to the folks here of course !;)

AdamLein 03-01-2009 03:06 AM

The Blea Sea voltage drop page talks about assuming that the engine compartment is 50C and the other compartments are 30C. I don't think my boat ever gets to be 30C inside.... what's the deal here?

andyjen 03-01-2009 09:00 AM

Thank you folks, would you use heat shrink tube as well as dielectric grease or is just one of them plenty?

Maine Sail 03-01-2009 09:12 AM

Do you have to used tinned wire? No.

Is it a very good idea to sue tinned wire? Yes!

Do you need to use heat shrink connectors? No.

Is it a very good idea? Yes!

Do you need to use dialectric grease? No.

Is it a good idea? Not with adhesive lined heat shrink connectors!

Proper crimping is critical to the entire system.

This will give you some more info.

Crimping Marine Terminations (LINK)

Also here is a great on-line wire gauge calculator:

Wire Gauge Calculator (LINK)

Also please don't buy wire from any of the big chandleries as most have been suckered into the Ancor scam.

Here are two exceptional sources for both wire and crimp connectors.

Sailors Solutions - Berkshire Wire

Sailors Solutions - FTZ Crimp Connectors

Sailors Solutions - Heat Shrink Crimper $39.95


These guys offer free shipping within the US..

Deadeye 03-01-2009 10:46 AM

You derate the wire if any part of the run passes through an engine room because of the reduction in ampacity as the ambient temperature rises. While maybe not in your case, the engine rooms of many powerboats can get pretty warm - it's just an attempt to come up with a universal set of rues.

MaineSail: Ancor scam ?

Maine Sail 03-01-2009 11:10 AM


Originally Posted by Deadeye (Post 456238)

MaineSail: Ancor scam ?

More to do with their pricing structure and packaging of brands. If a dealer does not choose to stock the Ancor line of wire and crimp products for example they (Marinco) yank the discount structure on Marinco and other the other lines.

They are like an 800 pound Gorilla and strong arm distributors constantly.

Why else do you now only see Ancor wire in places like Hamilton a chandlery who used to carry other brands of marine wire (Cobra) for about 1/3 the price..

Ancor is ABSURDLY over priced!

As of 2-28-09 chandlery pricing for 2GA battery cable per ft is:

2 GA Battery Cable
West Marine = $6.59 (Ancor)
Defender = $6.99 (Ancor)
Hamilton Marine = $6.03 (Ancor) $2.31 (NOT Ancor)

I pay $1.79 per foot for 2 GA Berkshire wire! Berkshire is made in the USA, generally of better quality than Ancor, and can still sell it for MASSIVELY less than what chandleries who bend over to Ancor can..

Between my price of $1.79 per foot and Defender's current pricing on Ancor of $6.99 that is a mark up of 390% !!!!! At the price available from that mark up is still a 300% mark up!

Avoid buying Ancor at all costs as there ARE alternatives. We the boating public have been getting raped for years!! A 10-30-% difference in mark up is one thing but a nearly 400% difference is just offensive!

Just my .02..

AdamLein 03-01-2009 03:12 PM

Maine, thanks for the consumer info... would have cost me an arm and a leg to learn that on my own :)

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