Originally Posted by colemj
I'm betting the OP will come back and show you that the price difference between local welding cable and shipping
in marine cable where he lives would allow him to fly to Morocco
for a dinner out.
We have welding cable connecting our inverter. Strangely, it is the only welding cable used on the boat - even though there are large amounts of 4/0 and 2/0 marine cable used elsewhere. This cable is crimped well and sealed with heavy glued heatshrink. No problems.
The thin strand argument doesn't make sense unless one's boat flexes like a plastic toy all over and one uses long unsupported runs where the boat flexing causes 90* bends to occur frequently. In this case, one should be arguing against the boat and not the wire.
The tinned argument is also strange seeing how marine wire outside the US is rarely tinned. Whole boats are made with untinned wire. Large expensive boats. It is only in the US where people start hyperventilating about untinned wire.
The heat rating, etc arguments make sense, and one should choose appropriately rated wire - welding or not.
Some good healthy pros and cons for tinned vs. non-tinned, and welding cable vs. boat cable. Non-tinned wire will work fine so long as it is protected from all the nasty air and water
on boats. The trick is to make that happen. Even the most skilled boat electrician can produce a heat shrink "air-tight" cover at the end of a cable where it mates with the lug and still have it leak.
Lugs are not perfectly round. People don't always use the best heavy-duty heat shrink (it should ALWAYS be the kind with adhesive inside and the adhesive should ooze out of both ends when you heat it up for your crimp). Heat shrink (especially the thin stuff) can split on sharp lug edges made by some crimpers (by a lot of different kinds of crimpers). Don't ever put a bend at the heat shrink. If it doesn't pull off right away it will creep off later and not seal right.
The cable should be secured so that it cannot move from its position relative to the post. Otherwise it will work itself and cause a "leak" leading to corrosion
. All tinned wire does is to help prevent corrosion
when it leaks
. Securing the cable helps prevent it from loosening at the post too.
I do use tinned wire and high quality (heavy duty/adhesive) heat shrink and always secure the cable so it won't move. But if you use welding cable you can do this and it may work out fine for you. However, I have worked on some European boats where the untinned wire had corroded so bad that the cables were in fact only half there - in the middle of the cables. Just because it is an expensive boat made in Europe
does NOT mean it uses the best quality materials or use best practices in installation
. Those of you who have not seen this won't have the same concern I have. Some of you won't see the pounding that some boats take in big seas either.
Regarding the rating of cables - they are important. Heat - oil
resistance - insulation quality. Some welding cables may be used in 150 degree environments like you can have next to engines but 99% do not. They are designed to be used in everyday work environments and usually have short cycle times so heat doesn't build up as much (knowing that this is not true in many cases). I am not a welder so am not expert on what kinds of welding cable is available but I bet most of you aren't either. I challenge you to go properly "spec" welding cable for the harsh environments in boat engine
spaces. I am sure you can do it, but do it.
Regarding wire size within cables: I wish that all boat cable was as flexible as welding cable but it isn't for two reasons. It has much smaller diameter internal wires. These can corrode much faster if air/water does get in there. So to the extent you can keep that from happening all good. The electrons just want a given amount of metal to travel and the air space between the wires is not that big a deal.
The other thing is the insulation though. Run of the mill welding cable insulation is not a rugged as boat cable. This makes it bendier but also makes it less durable. Welders consider it a tool that they replace when it gets bad, like you and I do with a hack saw blade. They need it to bend because they move in an out of tight places and are always coiling and uncoiling it. You don't have to do that with boat cable. You install it once and it stays.
If you wanted to consider your boat cables as maintenance
items that you inspect and replace every 5 years go ahead. Most of you will not do that.
Regarding made to order cables: I bet that anyone that does that will either have a cable that if they are lucky will be 5 inches too short or one that is 2 feet too long. I have been running 2/0 cable for a long time and I have never been able to measure the length with a tape measure. Even short lengths I do one terminal lug and try it to see how it will fit. I also make sure the terminals on shorter lengths match up to the configuration/orientation of the terminal on the other end. Sometimes you need a lug that is 180 degrees (or some other odd orientation) different from the other lug to be able to put batteries in series in close spaces. If you have to force a cable, even flexible welding cable, you will put torsion forces on both ends will cause the heat shrink to fail and get corroded. Not to mention causing the crimp to fail.
Which brings to mind that batteries are the very most corrosive places on a boat and where the corrosion protection has to be 100%. If you do the welding cable "right" no problem. Wrong and you check the battery fluids one time and the battery cable falls off of one of the lugs because the wire had dissolved.
Not trying to be argumentative but there are some who seem to think there is a conspiracy of boat cable fanatics trying to get everyone to buy expensive cable. An exaggeration for sure but sometimes it sounds like it. I absolutely hate to buy the spendy stuff myself. I spend hours researching products I want to add to my boat to get the lowest cost for what I am trying to do. I don't have a lot of money
. Whatever I spend on one thing is a trade-off on some other stuff I really need or want. But I won't compromise on wire or the installation
I don't think I will convert any of you diehards but it is a shame that some amateurs will actually listen to some of this cheap
advice. I almost fell out of my chair when the OP said that he got out of this thread that he should go out and buy welding cable since he decided that was the consensus. It is not the consensus.
I am NOT saying that you absolutely should not use welding cable, but if you do, please do as much as you can to install it the best way possible. Buy the expensive heat shrink. It is VERY expensive. Don't cut it too short to save a buck or not go back to the boat store because you didn't get enough the first time. Shrink it right. Secure the cables. Don't run them laying on anything - secure them with wire times and cable clamps out of the bilge
and not under the engine
. Don't bend them tightly at the terminal. Don't pinch them with anything - the insulation won't take it. Get heavy duty cable of the right size and spec. And inspect it often - look at and touch it the entire length of the cable, especially at the terminals. And then go boating