What gauge wire to use

Fish Assassin

Crew Member
Ok cleaning up all the wiring on my rig well the new motor project is happening.

I want to replace the old bus bar and 5 additional wires running the lenght of my boat and run two single wires to two new bus bars.

This is were I am wondering, if I run two #8 wires it should give me 40amps each if we are doing it correctly.

One is just for the Simrad/Nav/radar system

Second is for daul wipers, radio, bilge pump, nav lights, wash down system

Is #8 tinned marine wire the right way to go? These would go to two Blueseas Bus Bars

Everything is going to be switched thru a Blueseas Weaterdeck Fused switch panel.

Should be nicely rigged and ready to play once this is all done. :)
 
So I've been told pre rigged boats often come rigged with 12/2, many custom rigged boats are 10/2, 8 is over kill but so is everything on my little boat :)

Now just to get it done, hang the new motor and get out there
 
FA, it really depends on 2 things
1- the actual circuit length ( total distance round trip )
2 - the acceptable voltage drop for the devices.

Good plan running 2 separate circuits for the critical and noncritical devices, your electronics will thank you

Your sensitive electronics I would recommend you keep below 3%, the pumps and lights will likely survive up to 10%
Assuming a 30' (15' up and 15' back) circuit then 2 separate 8awg runs will give you 15a for your critical electronics and 40a for your reg devices like pumps and lights.
Not really overkill, likely a little light for your noncritical circuit but the likely hood of you running all your devices at the same time, well……..?
 
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It's 18-20ft complete circuit

Simrad, Radar on one

A single 12v nav light, bilge pump, two wipers, radio and wash down system on the other. Wash down is used most of all. One light hardly ever used, radio very rare to even have on, wipers..... It never rains here :)

8awg would give me 20a critical and 40a non critical
10awg would be 15a critical and 30a non critical

Id be safe with both, but yes 8 is not over kill
 
another tip here is rather than crimp and heat shrink

flux and solder before hand and make almost fool proof in your connections
last thing you want is black wires ....lol
 
Never solder anything on a vehicle other than circuit boards as it creates solid core wire which causes work hardening, breakage, resistance and fires.

Or so the marine electricians I work with tell me.
 
A good crimped connection, protected by shrink wrap to which some dielectric grease has been applied (after the connection is made) should last a very long time.
 
Never solder anything on a vehicle other than circuit boards as it creates solid core wire which causes work hardening, breakage, resistance and fires.

Or so the marine electricians I work with tell me.

yup what he said^^^^^

same in heavy and automotive. never solder, only crimp, also use the quality tinned marine wire and heat shrink with glue inside.

use long handle crimpers
https://www.channellock.com/909-THE-CRIMPER-Crimping-Tool.aspx
 
, also use the quality tinned marine wire and heat shrink with glue inside.

https://www.channellock.com/909-THE-CRIMPER-Crimping-Tool.aspx
Not going to get into the debate of solder or no-solder but……you are 100% right about the quality of the components used and too often I see people spend big money on wire only to terminate with a cheap china connector.
The offshore garbage sold at places like PA will not hold up for any length of time, often the barrels are 1/2 the thickness of a quality connector like Anchor or T&B.
The thinner material seems to quickly relax its pressure from temp cycles and allows oxygen into the crimp and off starts the corrosion, in order for a connection to last it must cold fuse the wire to the connector and stay there.
 
I rewire guide boats for inspection. 2, 10 gauge pos and neg. they com in pairs black and white. Never soldier any wires on a boat. Use bare terminals and double walled heat shrink with sealant built in.
 
funny then how all the electronics on a boat are solder.......
all i say is you can't be bothered or find it awkward
would still suggest using the glue heat shrink to belt and braces
seen quite a few boats with corrosion in the wires at terminals
cause we all know how many really good marine electricians are out there .........
i don't know one here on the coast
 
Havent met this guy yet have you?? one of the best on the lower island cares and a bit fussy when it comes to doing it right ask any local Guy whos Had their boats done by Glen .....
some before and after and some of his work

As for the gauge i always say go big or go home I ran # 6 gauge to front of boat for the "house" stuff and then big bus bars for downriggers went with 8,,, overkill perhaps but want as much power delivered as i can....
 

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Does he do work up here in the Comox Valley? I love to find an electrician the could complete at mine clean job like that. Mine I s much simpler though.
 
While the guts of the electronics on a boat may well be soldered, I'd have trouble finding any of the connections between the electronics and the electrical system on my Striper that are soldered.
 
Guess you need to tow your boat to sooke Owen road trips are not that bad then you can go fishing when its done off of sooke LOL
 
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