Issues About Welding on Boats?

If, "off" physically disconnects the current path from the hull to the battery, fine.

Otherwise take one of the terminals off whichever battery is first in line.

Are you a gambler?

It might be a concern about if the batteries are connected, they may be charging and emitting hydrogen gas.

The other issue could be that some folks may tie one side of their electrical system to the metal hull and the welder wants to be certain that any current return paths from the welding electrode don't go through the hull, back to the earth ground at the electrical panel and through the boat's battery charging system.

He's probably fried some boater's expensive charging system in the past.

<...emitting hydrogen gas...> Hydrogen goes straight up, though. The reason there is so little in the atmosphere is that its velocity, as a molecule at ambient temperatures, exceeds this planet's escape velocity.

I totally agree, but the U.S.C.G. still freaks out about venting battery compartments, etc. Obviously, in the case of well-sealed compartments, it is a concern. But if they leak like a sieve, then not a problem. The Hindenburg still falsely remains on the minds of nannies all over.

GA for that!

Yes - just like the issue with welding when a PLC + I/O cards are in place and wired in the control panel on a process skid. Some customer reps say you must remove them if you must add something to the skid by welding and others let us go ahead and weld with them in place and wired. Next time we "kill" one while welding, and this is TIG welding with a high frequency start, I'll let you know. Don't expect to hear from me soon.

I've never heard of that, and I've been welding energized and the occasional battery powered what have yous for decades.

I've not welded on the water, but in the rain and so forth without so much as a single zing or damage.

I agree with tcm, but as a former service worker SE has a point.

It could be a "company policy" that he picked up for whatever reason.

Interested in hearing about any actual pitfalls.

I agree with you about issues with the electrical grounds in shipyards, In this case, the boat is afloat (in freshwater) in a marina.

Do you still consider it may be of risk?

The welder was right and had probably learned his lesson through bitter experience. He has no clue whether your electronics were installed and grounded properly, and there are plenty of sneak paths for current to flow throughout a boat, especially one with a metal hull. One slightly corroded seam, joint, or connector will provide the return current an opportunity to find its way through a piece of electronics that never was designed to handle the current, and let's not forget the transients and spikes that get generated during all the arcing and striking.

I watched the same thing happen in a generating station when a welder didn't want to wait for a piece of equipment to be tagged out before he started his job. Even though he properly connected his grounding clamp to the station steelwork, it injected current into the instrumentation ground detection system; which then created lots of spurious ground fault alarms but thankfully no unit trip.

During the last year I have done a lot of welding on my boat (both in the yard and afloat) without caring about the batteries / electronics -just because anyone warned me about this before.

Fortunately nothing happened (so far).

Now that I know there may be a potential risk, what should I do?

1.- Disconnect the positive pole (by means of the regular battery switch)

2.- The latter AND also the negative terminal

3.- only the negative terminal.

4.- What about the electronic stuff that is grounded to the hull?

Thanks!

If I knew the guy knows what to do I would gladly let him proceed.... but he has no idea: he is very good at welding, but incapable of chewing gum and f_ _ting at the same time: he heard about this, and simply told it to me.

His way of preventing a mishap is just to disconnect the positive pole terminal from the battery... which is actually a complex way of doing what the battery switch does just by turning a lever.

as long as the circuit to the battery is open. Read what others with more experience in this matter have to say.

R&ddoc, on vehicles the precausion is for contrary to what you belief the alternator is connected to negative through the chassis and with a 100Amp Red wire to positive and there is no switch in sight. The only insulation between positive and negative is the coatings on the coil wires and the diode pack. The problem is "what is the potential on the floating earth of the welder" It will only become equal to that of the hull after current flow to pull it up or down to be 0 Volt.

He is correct to insist that you allow him to remove any system that can give you the oppertunity to accuse him of causing expensive damage to your property even if he knows it is not possible to cause the damage,?he has no way to know that you know and will not decide different if something goes wrong later. Experience taught him that client have that inclination if they experience problems after his welding job. It is all about covering your own ass and eliminate comebacks and expensive and time consuming arguments.

I posted the same question in the Trawler Forum, and here are some opinions:

ABfish: "Ive been around construction equipment for 35 years. I've always been told (and I've read in operators manuals) to disconnect one or both battery leads before welding on a piece of equipment.
That being said, I've welded on dozens of pieces of equipment and heavy trucks without disconnecting the batteries, and I've never seen an electrical failure directly attributable to the welding.
But, I can't blame your welder for being cautious. In my case, I own the equipment that I work on, so I'm not always as careful as I would be with other folks' equipment."

Sky in NC: "Welder probably got blamed for some electronics failure and decided to take no further chances. Can't blame him. And the failures may have had nothing to do with his work."

D.Duck44: "I have been welding on our steel yacht for over 20 years. On the mooring, in salt water. Some quite large jobs, both MIG and stick.
Never have disconnected anything, and have never had the slightest problem.
Only electronics on board are radios and GPS."

boomerang:"Your welder was correct in not doing any work until the batteries were disconnected. John Deere specifies the cables be removed on their electronic-controlled engines or the warranty will be voided"

There are some more opinions. I would say 50% is for being careful, and the other half says there is nothing to care about........

It's always better to err on the side of caution where expensive electronics are involved....I don't think anybody would argue that point....

^{SolarEagle, I agree and no one can make a statement that every thing goes through the ignition that is off without a comprehensive Diagram to read. Today a lot of electonics have memory facilities that need power to maintain the memory. Security systems, tracker GPS, coded radios, access control and various other systems are connected all the time.}

Disconecting the battery are the only known safe way to isolate what you do not know.

I've always heard to disconnect sensitive electrical equipment before welding. In fact, I've seen gas compressor skids that had warning labels to that effect.

In a somewhat related note, I heard about a guy that died when the engine on his airplane quit and he crashed. Turns out that he had done some welding on the plane and put the ground lead on the propeller...

And that would be another perfect example of a welder who didn't know jack shyte about how an arc welder works regarding current flow paths.

More than likely he arc pitted his engine bearings and they shelled out once put under a load for a while. No different than having run his engine out of oil for a moment.

Also what sort of aircraft was he flying that he couldn't keep control once the engine had quit? Seems there were compound failures in play for him to have crashed and died.

As for warning labels I am pretty sure everyone of us knows the real reason they are put on and in the vast majority of cases it not to give a valid rational sense warning of anything.

How many items have you bought and looked hate wearing plus usage direction only to see how to use it has 1 - 2 lines of explanation but the wring on how not to use it covers paragraphs of nonsense that anyone who's not an idiot would just know not to do with product?

I bought a frying pan a while back that had a huge warning label on it that stated to use caution because it may be hot while in use. WTF?

I think that info can be found in: FAA regulations and policies aircraft welding hand book.

AC 43.13-1B CHG1

Chapter 4

Download 2.2 mb pdf.

.. it's like welding across a hinge and wondering why it works like shit. ?

Duh.. never done that.

This guy may be a fine welder, but all jobs need to evaluated on a case-by-case basis. if I followed every precautionary measure before doing each and every job I would need three of me to get anything done.

Of course when you're billing $150 an hour and up as many welders do... taking all the precautionary measures necessary as well as possible is an excellent idea.

I can justify paying for a premium job done well, what I don't tolerant is paying for a premium job done poorly.

When you know how to competently weld.. plumb, electrify and so forth.. there's not a premium rate that appears justifiable.

As I know how to do a lot of stuff, and do it quite well (excuse my low self esteem ;-), it is very hard for me to find a guy that does a job better than me .... for a reasonable fee

Same here. I've went to farm out something I was not familiar with many times only to find out what they wanted only to end up telling them to go pound sand for the prices they were asking being for what they wanted I could wreck a lot of stuff learning how to do whatever it was myself.

Rather like auto mechanics and contractors of various trades. For what most charge for even basic work I will spend the money on buying the tools I need to do the job myself.

Depends who is saying they know how to weld. And a welding skill set is like any other skill, I can justify it because I know the cost between good and a bad welder.

doing this on a phone is a challenge

$35 - $45 an hour. That's what I ever charge at most for any of that work. Anything else is just being greedy.

Unfortunately in my area and general life experiences so far the more someone charges the worse their quality of work (and attitude about being questioned/called out over their crappy work) is.

I had a design and fab shop. When I was hiring welders, the welder that 'bragged' how good they are, was worth my time when they took a weld test.

now the experience I had with the welders that said,... 'it's been a while', 'hope I can remember how', etc..., (basically setting the bar low). Were hired on the spot after the weld test showed they knew what they were doing.

was wasn't worth my time when they took a weld test.

The current travels in the least resistance path. There is a possibility that the battery circuit may be the least path of resistance and current may flow through the battery.

Welding current being always high than the battery can handle - there is a danger of battery being damaged.

It is always safe to disconnect the battery terminals before welding on the equipement

DHAYANANDHAN.S

Another problem associated with welding in "boats" is welding on any part of the hull or bulkheads forming part of water/ballast/fuel tanks that are in contact with sea water, fuel, etc. If welding is carried out in these areas there is a risk of failure of the parent metal alongside the weld when the structure has excessive forces applied to it, e.g. rough weather. The reason this occurs is because of the rapid cooling of the weld and parent metal during the welding process.

I have seen several examples of this and the "best" was an USN destroyer in Hobart, Tasmania, Australia. They had been serving in far east for 9 months and were heading home and called into Hobart due to a slight problem. The vessel had a problem with a small split in the hull and the Chief Machinist's Mate (I think), had tried to fix the leak by welding it........well, they hit some rough weather and out popped the weld.......so, instead of a small split, they now had a "big" split. This was appropriately, blocked off with damage control wedges, 85% or so. Well they came over to our ship, (HMAS Anzac) to see if there was anything we could do for them. I went over, with our engineering chief and chief naval shipwright.......they could have gone into dry dock and had the repair carried out correctly, but, they were "busting their necks" to get home. The Chief "chippy" made up some wooden formers to fit around the split, drove in 4 x 5/8'' threaded studs through the hull (for keying), alongside the split with a Cox's bolt gun (similar to Ramset - explosive), and filled the former with quick drying cement........they sent us a signal when they arrived back in the States to say they arrived without further incident, even though the struck some very rough weather.

On steel hulled patrol vessels (100') whenever we carried out any arc welding we always disconnected batteries, this prevented Murphy's Law causing any problems, it was unnecessary on larger vessels.

This may be related. I have worked on race cars my whole life, when we started using the electronic ignition boxes in NASCAR Cup Series we were warned to take the box completely out of the car before welding. On one occasion when we had to do a weld right before a race we didn't have time to remove the ignition box and two laps into the race the ignition box failed. Never took a chance again. These ignition boxes are very durable and its rare to have any problems. We have never been warned about disconnecting the batteries but the power switch is always off unless the engines running.

I would be safe and disconnect the electronics, they can be very susceptible to transient electrons.

Good idea to isolate the electrics. It's no big deal to do so. I have a steel narrowboat for cruising the canals in the UK.

It is fitted with a galvanic isolator to prevent stray earth leakage currents through the hull and water when connected to a shore supply.

It is a long term thing to prevent the erosion of the hull due to electrolytic action - and it also has sacrificial anodes that plate the steel with zinc if there are any local currents (that could be caused by being in the electrical path of leakage from some other nearby boat).

I don't know what the open circuit voltage of a welder is - although I guess it drops to near zero when welding - but it could be quite high to start with - enough to inadvertently fry some modern electronic components on first contact - or after hit by high residual voltage peaks from collapsing magnetic fields at the instant the welding circuit is broken.

The request to isolate the batteries sounds like common sense.

Like switching off the electrical power before opening a control panel - which is something every qualified electrician does as a matter automatic routine - we would never dream of poking around in a panel where there are 'live' terminals.....would we!

Not only did HORACE40 give a good answer, but I believe it was tho most correct answer. Steel boats have corrosion resistance circuitry that is connected even when the battery switches are OFF. The welder may have saved the boat from a very costly accident.

Regardless of any comments about how long they have welded without disconnecting batteries I have seen on two occasions electronics in alternators and vehicle computers damaged at great cost to someone. The old vehicles with generators and none electronics had little concern but the modern systems are at risk. If an electrical field such as sun spot or EMF type can fry computers it will do so to a vehicle computer. BETTER SAFE THAN SORRY. Why take the chance for 30 seconds of prevention.

I have to say that I " feel " for the welder, as for disconnecting the batteries should be an easy request on your part. Sometimes it's hard to convince people of a safer or better way to do things, as an example:

A lady asked me last week how much it would cost to install a window style a/c unit in her modular home and which unit would I use. I suggested that she use a Frigidaire unit # FFRE 15335S1, This unit uses a slide out chassis. She then orders a Frigidaire unit # FGRC 1044T1, This unit does not use a slide out chassis and requires a 108T shell and trim kit. So I then told her that to install the 1044T1 would cost twice as much to install as the 15335S1. During this time I have gone to her home a few times and sat down with her to explain the difference between the two and how I had done the research to determine the most cost effective installation based upon her budget. I also told her that when selecting a unit it is necessary to review the units specifications sheet. She sent me a text last night asking why would a units specifications have anything to do with selecting a particular unit.

So in reading your post, I can see where the welder is coming from, it's probably not his first rodeo and from his experience he has determined the safest and most cost effective method required to accomplish the job.

GA!

I wish to thank you all for sharing your experience and your comments about this subject.

From now on I certaily will take much more care and completely disconnect the electrical system from the boat before doing any welding.

On the other hand, I must be very happy because extensive welding has been done on the boat while in the yard with (seemengly) no damage. Nevertheless, if "God does not play dice" (A. Einstein) I will not do it either

I have heard from a reputable welder that disconnecting the ground cables will prevent electronics damage. I had mentioned another source that recommended removing the electronics but he said it was his experience that was unnecessary. You should check for a ground plane plate as well and remove the cable until welding is complete.

If your engines are electronically controlled with a ECM, the harness connections need to be removed from the module. It's not the positive wires you need to be concerned with, it's the ground wires. I've seen plenty of ECM's fried from welders not disconnecting the harness plugs. The batteries, starter and sensors are much more robust, when it comes to stray voltage. It's not worth the risk, for the little bit of time it takes to disconnect the plugs.

Hi, fortunately my engines are "pre-techno" meaning they are not electronically controlled, no common rail nor intercooler or stuff like that: just 350´´aspirated diesels

Most definitely he was correct! Better safe that sorry, as the saying goes.

Just finished watching a doco on railways. The welders, before starting to weld on a diesel loco, had the electrician isolate the loco's computer so that "expensive" problems did not occur.

Interesting being have actually working a rail yard and saw the locomotive and rail service guys well on locomotives and attached rail cars many times while they sat there idling.

Batteries, computers, etc., are isolated in case a problem arises.......in almost all cases there will not be a problem, but, sometimes things can go wrong when welding and if it does it can prove very expensive. You may have been lucky, however there are those that may not have been so lucky.

Most commercial vessels, if in the "top of the range" have electrical systems with insulated returns.......in other words no electrical system including engine instrumentation has no earth/ground. Everything electrical, whether dc or ac systems are insulated from the hull....in these cases welding on the hull will not cause any problems at all. Unfortunately it is expensive to have this type of system installed in a vessel, but, in the long term it is the safest and best system to have, that is why ocean going vessels employ this system, it is also much easier to fault find and prevents stray current corrosion.....earthing lamps are always incorporated in these systems.

Looked on google.. found this. It's a good source about the subject.