Welding a steel boat while she is in the water?

[Hotboy]

Originally Posted by Boracay

The big no-no with welding is not the welding, it's the grinding.

Those red hot small steel bits can travel amazing distances and embed themselves in someone else's pride and joy. Then they rust and leave marks everywhere...

It might have been my imagination but with a 10 amp power supply to my welder I had trouble getting a good arc. My suspicions fell on the long run of the mains power down the jetty and I might have had the earth a bit too far from the job. Close as possible may be better.

Those rust marks can be dealt with by making up a solution of oxalic acid and painting it on the stain. Brick layers use it to clean wood stains off bricks. Just be aware that it can take the gloss off paint work, but a buff and polish should bring it back.

As for poor arc. It depends on the a number of things. Consider the length of the power supply lead (shorter the better), the gauge of the power cable (thicker cable=less resitance), If using welding rods, make sure they are dry by heating them in the oven before use. The list can go on and on but make sure all connections are good and after all that if you happen to be on mains electricity supply that has a lot of other users at the time you want to weld, then I suspect you won't be receiving enough current to generate a nice arc.
Hotboy.

[boden36]

No problems welding afloat, but I would not weld on the inside of the hull plating if that plating was submerged on the outside.
Regards,
Richard.

[Irie]

Welders I worked with on barges just let the ground dangle in the water next to the barge.

[Philsboat]

Keep the ground close to the area welded.I have seen welding currents follow the ground wires in instument cables resulting in melted cables.

Phil

[Simi 60]

Trying do some stainless welding now with a 150amp stick welder.
2.4mm rods, short welds x 6

I have a 7kva genset
A 5000va/120a inverter charger
A large solar array and a large battery bank.

The genset has no dedicated power point
I turn off inverter and get no power to power points, obviously
I run genset and get no power to power points.

Is it OK to weld via the inverter? I have done before for 1 inch welds but was told it was a no no by someone who may or may not know.
Batteries are at 100% and we would have about 70amps coming in if they were taking full charge.

[Cheechako]

I have welded barges dangling on the outside or in an aluminum skiff before. Not fun. It was safe I guess because I'm still here! But I have forgotten all the details as it was 40+ years ago. I do know at times I felt "electrified", hair standing on end etc.

[a64pilot]

Many years ago as an oilfield contract welder when the oil patch shut down in the early 80’s and work was hard to find, I remember welding in Oklahoma in the middle of Winter patches on the pipe of a sand dredge. I was in a tiny aluminum Jon Boat and was hanging off of it to weld on the bottom of the pipe, knowing if I fell in I was dead.
I do not miss that life. Looking back it was pretty stupid, but when your hungry, I guess you’ll do stupid things

[Cheechako]

Yeah, I dont miss it either! Mine was in the 70's when they were building the Alaska Pipeline. Many barges with train rails welded on them shipped out of Seattle. I was repairing a couple of those barges.

[puffcard]

Would add. Have a person be a fire watch. Grinding dust be careful, you will not be very popular with it flying around. I would unplug any electronic equipment that's nearby. I'm not a welder but worked with one, I was the one making the grinding dust. I wouldn't have any dampness near the work, including damp rags. I figured you are in seawater. Relying on an earth through water is dangerous and also unreliable. I remember we clamped the boat and kept the welder isolated on a heavy rubber mat. Now the guy seemed to know what he was doing, except one time we were on a salvage job and he did a small weld job with a couple 8D batteries, jumper cables and a coat hanger. It worked.

[a64pilot]

There is actually some pretty serious technology with welding rod and the flux it’s coated with etc. most of my welding was usually with low hydrogen rod, mostly 7018.
You can weld I guess with batteries and a coat hanger wire, but Lord only knows what strength the weld material is, likely not the 70,000 PSI of 7018 I’d bet.

[IdoraKeeper]

Originally Posted by a64pilot

There is actually some pretty serious technology with welding rod and the flux it’s coated with etc. most of my welding was usually with low hydrogen rod, mostly 7018.
You can weld I guess with batteries and a coat hanger wire, but Lord only knows what strength the weld material is, likely not the 70,000 PSI of 7018 I’d bet.

HO Ho Ho.....Quite the picture..standing in a Jon boat welding a pipe with an 8D battery and a coat hanger I love it...I know, I know that's not what you were doing. But it made me laugh.

[ironvalleyfab]

definetly pull the ground off your batteries. I have seen computers in New heavy trucks get fried from not doing that

[Cheechako]

Originally Posted by a64pilot

There is actually some pretty serious technology with welding rod and the flux it’s coated with etc. most of my welding was usually with low hydrogen rod, mostly 7018.
You can weld I guess with batteries and a coat hanger wire, but Lord only knows what strength the weld material is, likely not the 70,000 PSI of 7018 I’d bet.

Yep, 7018 was my favorite as it flows real nice. Too brittle for some work I guess , but high strength and easy welding for a welder like me! There were a lot better welders than me.

[Fence Man]

FWIW, there is a new school of thought that suggests that the batteries offer some level of protection for ECMs and ECUs by acting as a buffer against electrical current spikes. I've never unhooked a battery while welding on a boat, but I certainly did, as per the manufacturers recommendation, when I welded the flatbed on my new truck. Does anyone have first hand experience with a bad outcome, one way or the other?

[Simi 60]

Originally Posted by Simi 60

Trying do some stainless welding now with a 150amp stick welder.
2.4mm rods, short welds x 6

I have a 7kva genset
A 5000va/120a inverter charger
A large solar array and a large battery bank.

The genset has no dedicated power point
I turn off inverter and get no power to power points, obviously
I run genset and get no power to power points.

Is it OK to weld via the inverter? I have done before for 1 inch welds but was told it was a no no by someone who may or may not know.
Batteries are at 100% and we would have about 70amps coming in if they were taking full charge.

Well, in reply to my question I did the job with genset and inverter on.
No one died - job was successful.