WELDING VS MARINE-GRADE CABLE

tidetim
tidetim Registered Users Posts: 10 ✭✭
Getting ready to do a fairly large upgrade of my boat's battery system. Will wind up with 12 6 volt batteries in 2 banks (12 volt system). Fairly large amount of new wiring. Would appreciate the opinion of the use of welding cable (which comes in various colors now; black, red, yellow) instead of the much more expensive marine-grade wire (eg. Ancor).

Comments

  • mcgivor
    mcgivor Solar Expert Posts: 3,854 ✭✭✭✭✭✭
    Anything marine comes at a premium for good reason especially in a salt water environment, electronic equipment will have coatings on printed circuit boards, liquid insulation on terminals and so forth, to keep the elements out which would accelerate degredation. Taking these things into consideration by preparing terminals with appropriate barriers it would be possible to utilize welding cable in leu of the more expensive " marise grade " conductors. If there is one criticism with welding cable, which I use, is the insulation tends to be extremely thick, obviously for mechanical protection, along with very thin strands which can displace if the correct terminals are not used. Just some random thoughts.
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  • Estragon
    Estragon Registered Users Posts: 4,496 ✭✭✭✭✭
    Just IMHO, welding cable (with good quality termination) would do the job, unless you need major contortions to run wire. If so, it seems to me the marine stuff is more finely stranded and easier to work with.

    With three parallel connections in each bank, you'll want to keep an eye out for corrosion etc anyway. Are you fusing each parallel connection?
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  • Dave Angelini
    Dave Angelini Solar Expert Posts: 6,728 ✭✭✭✭✭✭
    As the guys have stated but I would ask what are you going to do with the boat? If it lives in a marina and used sparsely as almost all marina boats are then use the weld cable if you are good at crimping it.

    If you going out on the big blue ocean, taking her to the tropics, living in places where the people on the boat are the only ones for a 1000 miles, then I would use the best available. Corrosion in weld cable will happen long before marine grade. The excellent results I have seen
    on boats that have circumnavigated for decades bears it out. Anchor is an excellent product and a joy to crimp!  Well it was back in the day....
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  • jonr
    jonr Solar Expert Posts: 1,386 ✭✭✭✭
    edited April 2018 #5
    Just to clarify for some readers, marine cable is tinned (each strand separately), which makes it much more corrosion resistant.  I've dealt with enough "turned black" untinned wire that I have a preference for tinned.

    Some say that the black oxide can be removed with vinegar and salt - I haven't tried it. 

    I agree that electrical grease should help - preferably applied before connectors are attached (people who have tested this say that even dielectric grease doesn't interfere with conductivity in a tightly compressed connection).

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  • Dave Angelini
    Dave Angelini Solar Expert Posts: 6,728 ✭✭✭✭✭✭
    edited April 2018 #6
    And  some welding cable is also tinned.... Clean, dry, torqued connections will go a long way anywhere.
    They both have UL ratings but the marine meets coast guard and the american yacht/boat standards.
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  • cow_rancher
    cow_rancher Solar Expert Posts: 117 ✭✭✭✭
    As the guys have stated but I would ask what are you going to do with the boat? If it lives in a marina and used sparsely as almost all marina boats are then use the weld cable if you are good at crimping it.

    Which brings up a question, do you tin welding wire, or for that matter any large diameter cable, like 250 MCM before you crimp on the lug, or not?  By tin I mean use solder to make it a solid soft conductor.

    Rancher
  • mike95490
    mike95490 Solar Expert Posts: 9,583 ✭✭✭✭✭
    edited April 2018 #8
    Any cable to be crimped, should be plain, do not tin it.    Marine cable has each strand tinned at factory, they are not soldered together.  When a cable is soldered, the solder wicks up into the strands, fusing it into a giant single strand.  When any vibration or flex happens, the motion is focused on the juncture of stranded + wicked. Then the cable degrades and breaks inside the insulation, which looks virgin and hides the evil beneath.

    When cables are properly crimped, with large hydraulic crimpers, the enormous pressure fuses the strands and the lug together into a  gas tight connection.  You can apply vaseline or anti-ox grease to the strands before crimping, the excess will be forced out of the joint, which will still fuse into a homogeneous piece of metal. Factory tinning of cable or lug will not affect the joint internally, the tin helps protect the copper until it is crimped.
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  • Dave Angelini
    Dave Angelini Solar Expert Posts: 6,728 ✭✭✭✭✭✭
    Definitely as my main man said! DO NOT TIN.  
    Adding on, it is especially important not to tin anything in a maritime/mobile application because vibration can fracture the joint. Boats and their engine/genset or an ambulance need all the good engineering they can get. Space also.

    The old joke I tell about working in a Marina and an owner looking at my resume saying, wow you worked in aerospace that must have really required quality workmanship. No sir, in marine electronics, if the boat sinks there is a very good chance they will get in a life raft and hunt you down. In aerospace they rarely come home....
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  • Dave Angelini
    Dave Angelini Solar Expert Posts: 6,728 ✭✭✭✭✭✭
    Buy pre-tinned welding cable! it is cheaper than Anchor marine cable. Whatever you do buy the right crimping tool if you are going to do this very much.
    "we go where power lines don't" Sierra Nevada mountain area
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  • jonr
    jonr Solar Expert Posts: 1,386 ✭✭✭✭
    I did a quick search and got $4.83/ft for tinned 1 AWG welding cable, $3.44 for 1 AWG marine (not Ancor) cable and $3.19/ft for Ancor.  Not tinned welding wire was $1.80/ft.

    I am available for custom hardware/firmware development

  • scrubjaysnest
    scrubjaysnest Solar Expert Posts: 175 ✭✭✭
    My only thought on this is the welding cable I'm familiar with doesn't have the gas/oil rating of the insulation marine grade does. Personally I use marine grade on the RV and boat both.