# Is arc welding underwater fraught with danger? **URL:** \ **Category:** Factual Questions\ **Created:** [March 1, 2015, 9:25am UTC](https://boards.straightdope.com/t/is-arc-welding-underwater-fraught-with-danger/713920 "2015-03-01T09:25:17Z")\ **Posts on this page:** 8\ **Page:** 1
**Author:** ![Duke\_of\_York](https://avatars.discourse-cdn.com/v4/letter/d/f6c823/32.png) [@Duke\_of\_York](https://boards.straightdope.com/u/Duke_of_York)\ **Post date:** [March 1, 2015, 9:25am UTC](https://boards.straightdope.com/t/is-arc-welding-underwater-fraught-with-danger/713920/1 "2015-03-01T09:25:17Z")
How do divers arc weld under water without electrocuting themselves? Are the welding units basically the same a normal welders but with added insulation? I can arc weld on land, could I do it under the sea, or is the whole process completely different? ---
**Author:** ![Ken001](https://avatars.discourse-cdn.com/v4/letter/k/43a26b/32.png) [@Ken001](https://boards.straightdope.com/u/Ken001)\ **Post date:** [March 1, 2015, 9:46am UTC](https://boards.straightdope.com/t/is-arc-welding-underwater-fraught-with-danger/713920/2 "2015-03-01T09:46:52Z")
Oxyacetylene ---
**Author:** ![Duke\_of\_York](https://avatars.discourse-cdn.com/v4/letter/d/f6c823/32.png) [@Duke\_of\_York](https://boards.straightdope.com/u/Duke_of_York)\ **Post date:** [March 1, 2015, 9:54am UTC](https://boards.straightdope.com/t/is-arc-welding-underwater-fraught-with-danger/713920/3 "2015-03-01T09:54:12Z")
> [@Ken001](#): > > Oxyacetylene The diver I saw on TV was using an arc welder. ---
**Author:** ![Duke\_of\_York](https://avatars.discourse-cdn.com/v4/letter/d/f6c823/32.png) [@Duke\_of\_York](https://boards.straightdope.com/u/Duke_of_York)\ **Post date:** [March 1, 2015, 9:58am UTC](https://boards.straightdope.com/t/is-arc-welding-underwater-fraught-with-danger/713920/4 "2015-03-01T09:58:40Z")
Forget it, I looked it up on YouTube, [- YouTube](https://www.youtube.com/watch?v=wBhZIUyXfw4) ---
**Author:** ![beowulff](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/beowulff/32/542_2.png) [@beowulff](https://boards.straightdope.com/u/beowulff)\ **Post date:** [March 1, 2015, 3:29pm UTC](https://boards.straightdope.com/t/is-arc-welding-underwater-fraught-with-danger/713920/5 "2015-03-01T15:29:58Z")
The voltages in Arc welding are really low - a few tens of volts. They aren’t really an electrocution risk. ---
**Author:** ![busterpickle](https://avatars.discourse-cdn.com/v4/letter/b/258eb7/32.png) [@busterpickle](https://boards.straightdope.com/u/busterpickle)\ **Post date:** [March 1, 2015, 4:55pm UTC](https://boards.straightdope.com/t/is-arc-welding-underwater-fraught-with-danger/713920/6 "2015-03-01T16:55:15Z")
It’s not just “volts” that can cause an electrocution. Case in point, a Van de Graff generator, the likes that make your hand stand on end when you touch it, is at around 20,000 volts. However, the current is very small, and it won’t stop your heart. Working on a piece of equipment, I took a multimeter to some terminals to check the voltage and it was around 2.8 VAC, and I was like: “Good to go!” I stuck my hand in there and my arm was immediately locked by the voltage and my friend had to pull me out. My arm was slightly discolored form the elbow down and was extremely sore, as if I had gone to the gym and wailed on my biceps/triceps. Same friend, who was even less patient than me, did not take a multimeter to similar terminals and was hit with something like 440 VAC, it looked like it disintegrated a chunk of his palm away. ANY WAYS… I have never arc welded under water, but, maybe they have a pressurized airline that is coming out the nozzle blowing the water away as you weld? ---
**Author:** ![beowulff](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/beowulff/32/542_2.png) [@beowulff](https://boards.straightdope.com/u/beowulff)\ **Post date:** [March 1, 2015, 5:02pm UTC](https://boards.straightdope.com/t/is-arc-welding-underwater-fraught-with-danger/713920/7 "2015-03-01T17:02:05Z")
> [@electronbee](#): > > Working on a piece of equipment, I took a multimeter to some terminals to check the voltage and it was around 2.8 VAC, and I was like: “Good to go!” I stuck my hand in there and my arm was immediately locked by the voltage and my friend had to pull me out. My arm was slightly discolored form the elbow down and was extremely sore, as if I had gone to the gym and wailed on my biceps/triceps. And what was the DC voltage? 2.8vac is too low to be felt even on wet skin. ---
**Author:** ![Machine\_Elf](https://avatars.discourse-cdn.com/v4/letter/m/82dd89/32.png) [@Machine\_Elf](https://boards.straightdope.com/u/Machine_Elf)\ **Post date:** [March 2, 2015, 1:36pm UTC](https://boards.straightdope.com/t/is-arc-welding-underwater-fraught-with-danger/713920/8 "2015-03-02T13:36:12Z")
> [@beowulff](#): > > The voltages in Arc welding are really low - a few tens of volts. > They aren’t really an electrocution risk. This. If the torch is at a few tens of volts, and the structure being welded on is properly grounded, then the voltage to which the diver is exposed is very low, not enough to drive significant current through skin. If the diver is also contained in a drysuit, then there’s no issue at all.