Rewire-- why did they use welding cable

CaptDana · Post by **CaptDana** » Feb 12th, '07, 12:10

Well- I am in the midst of my 28B rewire- relocating a main panel under the dinnette seat and going to a START HOUSE system. As I am removing old wiring-- I noticed that Bertram used welding cable for my main leads-- Belkin welding cable.--- Can welding cable be used-- what are the Plus and minuses on this-- (I happen to have 100 ft of this and it would save some $$$) Also-- What is the smallest size wire I should use for my Main ciruits--is #2 ok? Mains will be going to a panel under the dinnette opposite the bulkhead wall- so the runs will not be long.
Too much snow here in Michigan!!1
Thanks in advance

CaptPatrick · Post by **CaptPatrick** » Feb 12th, '07, 12:18

Dana,

Welding cable is actually a higher quality than standard cable of the same size. Standard cable has less strands and is thereby stiffer due to the individual strand size. For that short run, #2 is fine.

You're good to go...

Br,

Patrick

Harry Babb · Post by **Harry Babb** » Feb 12th, '07, 12:38

Electricity travels on the surface of a wire. Welding cable has thousands of strands therefore it has more total surface area of wire than the same size industrial or residential wire. Welding cable can carry extremely high amperage loads.

The downside is that its not "tinned" and subject to corrosion more so than wire disigned to be used in the marine enviroment.

My opinion is that if the wire and the wire covering is in good shape use it again.........at todays copper prices you will save a lot of money. Besure to coat the end connections with a good electrically conductive grease such as Noaolox (spelling ?????)

Harry Babb

ScottD · Post by **ScottD** » Feb 12th, '07, 12:38

Capt. Dana, I wouldn't be afraid to use the welding cable either. The primary draw back is the insulation is rubber, and not overly srong or waterproof and the conductor strands are not tinned. If not terminated correctly it is prone to corrode. On the plus side, welding cable is rated to a higher ampacity for a given wire size due to to many, many strands.

ScottD

CaptDana · Post by **CaptDana** » Feb 12th, '07, 14:48

Thanks for the quick replies--- my intention is to replace the existing cable with newer cable-- I did notice some cracking in my mains on the boat--- but this cable is 35 yrs old.--I'll probably be able to sell it for lunch money- I find this all very interesting--- Bertram used tinned wire in the looms etc- and that wire is in great shape--of course I am in fresh water.

The only thing I have seen bad on the welding cable is one area that is was bent over an engine bed-- it cracked-- Are the abyc standards way overkill -- I have read articles such as a Don Cassey Boat US scaring you not to use this kind of cable.

Capt dana

Bruce · Post by **Bruce** » Feb 12th, '07, 16:52

Harry,

When pulses of electrical energy travel along a wire, they produce an excess charge on the surface of a wire, and they cause an electric current inside the wire.

But because the metal acts like an electro magnetic shield, at first the path for electric current only exists on the surface.
As the millionths of seconds pass by, more and more electric current appears deep inside the wire. Finally after a fraction of a second the current is everywhere inside the wire.

On ac this starts with every pulse of current.

On AC "skin effect" causes current to avoid the middle and appear on the surface. But it really has no effect on 60 hz frequencies. It is much more prevalent on higher frquencies.

They do use hollow pipes on high frequency high power radio tranmission coated with copper. On UHF and microwave skin effect current is so thin they plate the copper with silver and the current exists only in the thin layer of silver

You can for the most part ignore skin effect unless your dealing with audio cables, antennas and transmitters, pulses and lightning strikes, etc.

If current only flowed on the surface you could replace heavy gauge wire with plastic tubing of the same diameter with a copper coating, of which you can't do.

Welding cable strands are small and many for current capacity with flexability. Welding cables are constantly being moved, coiled and such. Larger strands would eventually break for the back and forth movement.

ScottD · Post by **ScottD** » Feb 12th, '07, 17:03

Bruce, I was taught as Harry said, that the elctrons traveled predominatly on the outer portions of the copper, I thought that's why welding lead is rated higher for a given circular mil. It's been over twenty years since I have studied any electrical theory, so I'm in no position to disagree, there's a lot of theory that can change in twenty plus.

ScottD

Bruce · Post by **Bruce** » Feb 12th, '07, 17:08

Scott,
I don't know if this is the case but some mistake the magnetic field which runs around the wire for the current flow.

In Memory of Vicroy · Post by **In Memory of Vicroy** » Feb 12th, '07, 17:23

Bruce is correct - the 'skin effect' is only exists in ac current, and then only of any signifigance at very high frequencies. I doubt weling cable of a certain diameter has a higher dc amp rating than a solid conductor of the same diameter. We use stranded wire on boats due to vibration and movement. We use solid wire in houses since they don't (we hope) move.

UV

Rawleigh · Post by **Rawleigh** » Feb 12th, '07, 18:15

You can also solder the connector onto the wire, which helps prevent corrosion at the connector. Use glue lined heat shrink over that and corrosion shouldn't be a problem. You can also put heatshrink over any cracked areas on the existing wires if you want.

Charlie J · Post by **Charlie J** » Feb 12th, '07, 20:25

bruce
is the skin effect the same as what we call in the field shielding cable, we use it underground up to 1000 mcm, its grounded at all terminations to dissperse all the stray current thats built up, granted iam only talking distribution 2400 to ground 7800 phase to phase

In Memory of Vicroy · Post by **In Memory of Vicroy** » Feb 12th, '07, 21:13

Charlie - yes, its the same when the voltage gets up into that range. For the same reason we use flat copper strips for our boat grounds, since the galvanic voltages (stainless trying to eat bronze, for example) are in the static electricity range (say lightning), but almost no current (amps).

I used to do ham radio in my youth, and rediscovered all this in prep of installing my ICOM 802 sideband on AJ a few years ago. Low voltage, high amp DC or AC is a totally different animal than hi voltage, hi amp AC, or RF stuff.

UV

Bruce · Post by **Bruce** » Feb 13th, '07, 07:08

Like UV touched on, thats more for static charge grounding in buried cable.

You use sheilded cable on equipment you want to keep EMF out of unless your producing strong saturating MF's.

On overhead lines you have corona problems which interfer with RF and TVI signals and is a hugh contributor to the ozone depletion, more so than freon.

Many times on boats I see shielded cable run with neither end of the shield grounded. A waste of time.

What is the smallest size wire I should use for my Main ciruits--is #2 ok

Feed mains are determined by overall load and length of run.
Unless you have high current devices like an elecra-san, crown head, electric reel, etc, #2 should be fine on the 31.

Make sure what ever size you use you match that wire size with the proper size breaker or fuse from the battery.

gplume · Post by **gplume** » Feb 13th, '07, 07:28

Saw this post...and wanted to shaer with you a couple of thoughts. First, all the discussion of the current traveling in the skin is really more applicable to high frequncy. I beleive for the DC we are talking about, the skin effect is most likelynot a factor.

I too am in the middle of a rewire on a B 31. 35 years in salt water, and the OEM bertam primary wire is almost in perfect shape. Kind of makes you think about the requiremnt to use tinned wires in a marine environment may not be idle flap.

Regarding welding cable....I have it a well, and am not going to replace it. However with all due respect to the responders, I beleive the most compelling reason to upgrade would to bring it up to the modern codes. I may be mistaken, but I beleive ABYC may require tinned wire, and may not recomend welding cable...(don't know the exact words in the spec.). The issue will be when you get some pompous marine surveyer looking at your boat most likely when you want to sell it, and then gig you for not having the right wire. The expense of the material is small if you consider it could take thousands off of the value of you boat later. My advice, get the ABYC code book and try to follow it within reason. It will only ad value later on.(gplume@cox.net...may be able to help you with this.)

Bruce · Post by **Bruce** » Feb 13th, '07, 08:39

I work with a bunch of surveyors.

The only comments I see about wiring is corroded connections, undersized wire, no support, poor connections, no anti chaff.

Not one has ever mentioned the boat is not wired to ABYC standards.

Now that being said, will the cowardice of the insurance companies in the future mandate the use of ABYC standards. Maybe.

But if you use closed end lugs on a cable and heat shrink tubing, I can hand you two identical cables and I bet you can't tell which one is copper and which one has a tinned coating.

Now all the wire I ever use is tinned coated for anti corrosion protection. It has nothing to do with ABYC standards or recommendations.

The only thing I have seen out of the ABYC standards is higher costs and cut corners on production boats.
Standard factory wiring 30 years ago was not all that bad with what they had to work with.

Until you have to pull a permit to do boat wiring and have it inspected and have marine electricians certified, ABYC standards don't mean crap.

Harry Babb · Post by **Harry Babb** » Feb 13th, '07, 08:52

Bruce,
You gave an in depth explaination of electricity traveling thru a wire. Thats a bit more information than I got from my "Tailgate Engineering" classes that we have down at the river. Thanks..........

I have been using the "Boat Wire" for both the 12 V and 110V rewire on my 31 "De Nada". I have pulled out several miles of the original wire as well as 41 years of crap such as lamp cord, romex and who knows what else. The "Boat Wire" is expensive but I figure its worth it. A lot of the wire that I pulled out has deterioated to a point that just stripping it back and twisting it causes the strands to break.

I appreciate your explaination but still have a question.........Can stranded wire carry more current than solid conductor??? I have always believed that to be true but by no means am I an authority on the subject.

Hey guys...............this is why I enjoy this site so much........I would like to participate in more discussions like this one........paint.........glass.......electricity.........mechanics and on and on.

Harry Babb

CaptDana · Post by **CaptDana** » Feb 13th, '07, 12:01

Thanks for the input guys-- While removing my "old" 14-10 gauge wire = I couldn't help but to note that the wire itself was in in good shape--and was tinned from bertram back in 1972 The only reason I am replacing this wire is the outside of it is discolored from the wire clamps, bilge dirt, etc. I will leave the welding cable for grounds and replace my mains with Red #2 Tinned wire-(happen to find some in the garage yesterday) --At least the hot leads will be red. --I agree--the only one to probably call you out on it is a bull headed surveyor when I sell. UV and Bruce--thanks for the lesson---Learned more in this discussion than a whole year of school.

What a great place we have here.

Bruce · Post by **Bruce** » Feb 13th, '07, 16:05

Can stranded wire carry more current than solid conductor

Thats a loaded question because of the varing kinds of voltages, frequencies, current, signals, pulses and such.

For the most part the answer is no and that solid wire has less resistance so it can carry more current.

This is nothing that anyone here will see in rewiring the boat. We are talking about things that the average meter will never be able to tell the difference between the two.

It is a common belief even among alot of electricians about the path of current. But most electricians have very little theory knowlege.

They have been trained based on procedures and codes to do things a certain way.

I got 18 months of deep theory when I was in school to get my Avionics cert. I sometimes refer back to the text books when answering some questions because my mind has become so feeble.

If you think a boat is tough trying to find a problem, try getting a repair ticket on a DC-10-10 for intermittant warning lights.

Btw on my comment about using sheilded wire, only ground one end. If you ground both ends it will act as a giant dipole antenna.

and was tinned from bertram

Are you sure it is tinned wire or is the strands just soldered to give a better bite to the clamp screw used on some fuse holders and breakers used back then?

Charlie J · Post by **Charlie J** » Feb 13th, '07, 16:32

bruce
thats me no theory all practical hands on, in a nut shell

Bruce · Post by **Bruce** » Feb 13th, '07, 16:42

Without us hands on guys, the theory people wouldn't get out of first gear.

Its just nice to know enough theory so when the resident egg head comes down to the job site from the home office, we can at least nod our head at the right times.

gplume · Post by **gplume** » Feb 13th, '07, 21:14

Bruce-

Ok....so ABYC does not mean squat. I am not necessarily a rules guy myself, so I canot disagree with you...., but in your reply you say;

"Now all the wire I ever use is tinned coated for anti corrosion protection. It has nothing to do with ABYC standards or recommendations. "

No I guess the recomendation to our friend with the original post is....use marine tinned wire, not welding cable? Is that the message?

I am no survey pro, but the two I ran into doing surveys pointed out numerous ABYC code violations. Guess I must have hit couple of church ladies.

To the other responders;
Last point to clarify; With DC, unless the voltage is the stratosphere...It does not travel in the skin of the cable. In the high frequency domain, the skin is where its at, and that is why ribbon is particularly good for grounding high frequency equipment, but for DC, the bulk wire carries the current.

gplume · Post by **gplume** » Feb 13th, '07, 21:43

Guys-

One thing I forgot to add. My understanding is that stranded cable is used for all wires on a boat strictly to islolate the stress. The floppy welding cable or nice supple primary wire is so that vibration or other random motion is not transmitted to the mounting point.

-Giff

In Memory of Vicroy · Post by **In Memory of Vicroy** » Feb 13th, '07, 22:04

Tinning - that is, all the strands of the wire are coated with solder - is common in marine wiring. You can get any size stranded and tinned, including welding cable. So let's get apples and oranges in their proper slots.

If plain copper stranded (or solid) wire is isolated from salt water, it will last fine. On the other hand, if water gets inside the insulation, it will corrode, turn black and go to dust. Tinned wire will last a little longer in those conditons, but not much more. If you want to use wire that will last a very long time in very adverse conditions, use the wire that is intended to be buried undrground. It has a gummy sealer in it and will drive you up the walls trying to splice or lug it, but it will lay in salt water for 100 years and not corrode. Point is, just use common sense, keep the wire supported, out of the bilge water, heat shrink the ends and go about using the BEst Boat Ever Built for fun,not worry.

UV

Bruce · Post by **Bruce** » Feb 14th, '07, 06:25

gplume,

I don't think the two surveyors you talk about were church ladies. I think they are misguided in their thinking.
If you are surveying a new boat that was wired according to ABYC standards and someone either changed or added wiring that did not match the standards, then that would be a valid point.

If they were looking at a boat not wired to ABYC standards and remarked that violations to ABYC standards were present then that makes no sense at all.

Of course there are going to be ABYC standards violations.

I use tinned wire cause being in the service business I want to reduce my liability in case of a problem.
Copper wire properly prepared can reduce the amount of corrosion quite a bit. If I were wiring my own boat, I would reuse good wire if I couldn't afford to buy new.

randall · Post by **randall** » Feb 14th, '07, 09:01

bruce.....most of the artists, surfers, and musicians i know go to the same church as you...............even had a prayer meeting in the front of a pick up last saturday night between sets

CaptDana · Post by **CaptDana** » Feb 14th, '07, 11:23

Yes, the 14-8 gauge wire is tinned and not just coated on the ends. (cut the wire in the middle and stripped it-- tinned ) My 28 B is a 1972 -- seems Bertram was ahead of the game in this area- I have seen many other boats of the same era that have wire that is plain jane and has disintigrated.

gplume · Post by **gplume** » Feb 14th, '07, 22:14

This one is a good, I'm getting into this;

Capt Dana-
Could not agree with you more....the quality of the OEM Bertram wireing is amazing. All of the wire (excpept the battery cables under discussion) is tinned all the way through and good stuff. Mostly I am replacing what was added on over 35 years....with maybe a couple of OEM wires in the mix. I have been chasing a corrosion issue so I really scoped out the bonding system. Way, way better stock from Bertram than what is on my folks late 80's trawler yacht. These guys did good work.

Bruce-
This leads me to the survey talk. I think we had a misunderstanding. What the survey guys pointed out was all the non ABYC stuff added on, (Anybody out there got a 100% stock 35 year old boat?) and on my boat there was plenty....lots done by "reputable" marine proffesionals, and very hack if you "looked under the hood", and the rest by MR "Bad wrench". I do not remeber any pointing out of any issues on the OEM Bertram stuff. Nor any mention of the stock OEM Bertam battery cables, which on my boat say "welding cable" right on them, so that was not an issue. It seems the guys I have been assciated with had a good nose for what was "non stock" or added on. So, my point was originally, if you are going to replace or add something, do it to the highest stds...of course, thats my opinion and I'm sticking to it.

Agree with the comment.....use common sense, and all will be fine.

Praying for spring here in NE - Giff

bertram31.com

Rewire-- why did they use welding cable

Rewire-- why did they use welding cable

Interesting

thanks and a quick note

Bruce

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