Arc welding shock hazards in wet weather

[bjcsc]

Do tell, please. What are the expected differences?

Echo...

[Defective]

Well...

The only time I've ever done much welding on an intentionally grounded task was building a shop a bunch of years ago. The structure in question was a framework to be poured into the slab and I was welding a steel curb into it after the walls were up and the frame itself was finished and bonded to 4 grounding rods.

When I started welding in the curb, I found that the welder seemed to be putting out a lot less power than expected. I checked the settings repeatedly and couldn't figure out what was wrong. After arguing with it for an hour, I decided to do some testing. I set up some scrap (of the same material) on the bench and tried welding it there. By this time I had cranked the machine up to 225 amps (max). The arc was incredible.

My conclusion at the time was that I was doing something wrong. Then a friend pointed out that the only difference with the framework was the ground connections.

We pulled the ground connections while I finished the curb and I went back to the 120 amps I had been using all along and there were no problems.

[2manyrocks]

Maybe this question needs to be asked on the Miller Welds or Hobart Weld Talk websites.

This is what not to do: NASD: Farmer Dies When Electrocuted While Welding Feed Bunker Wagon

[Defective]

From what I read there:

1) victim was leaning against the metal wagon which, in turn, had the work lead connected to it.

2) victim had the (apparently worn out) welding leads lying across his lap.

I would venture to guess that none of the other issues pointed out in the article were factors in his demise. He made himself into a short circuit across the output of the machine.

[Reg]

If I "HAD TO" weld in the rain I would probably ignore the instructions about grounding the work piece and deliberately "float" it from ground.
Sure the welder's ground cable would be attached to the work piece, but it and the work piece wouldn't be attached to ground/earth/soil/dirt.

[GinNB]

Good argument for a DC welding machine. I've welded up an aluminum ladder in the rain hanging off of the aluminum rear door of a 3ton cube van and felt the "buzz" with no consequences other than "Gee I really wish it weren't raining". All of my equipment was in good repair though.

[Aquaman]

I was laying under a trailer on the wet ground welding one time and had the tingling for a long time before I realized what it was. At first, I thought it was just the wet clothes. I've been doing electrical work since '83 and have had lotsa close calls, but I will NEVER weld in wet conditions again. It's not worth it.

[Soundguy]

Guess my buddy that does underwater welding has a problem huh!

soundguy

[Reg]

Underwater welding is a GOOD illustration of WHY the workpiece should be "floated"(pun intended).

[FlaDon]

Try welding inside a boiler. Nice thing about that is you only have to worry about one lead. And a DC circuit can kill you as fast as the same voltage AC one. It all depends on where the contact is made, voltage, and current. DC contracts muscles. If a hand closes on a DC source, the only way to free it might be to kill power to the circuit. A known hazard with the railroad industry where 64V and up DC is common.