Most people think that underwater welders are all wet. Pardon the pun. I just couldn't resist.
But seriously, the term "underwater welding" is kind of misleading because some underwater welds are actually dry and are welded just like you and I would weld in the shop.
When I was in welding school, an underwater welder visited one day and gave a slide presentation of underwater welding jobs he worked on all over the world. Oil platforms in the North Sea, Barges, thousands of feet under the ocean....Scary.
I saw a this youtube video on underwater welding and it reminded me of this presentation I saw while I was in welding school. It seems some things have not changed a whole lot.
I remember the guy that gave the presentation talking about welding in a diving bell and that it was very tough on the body. He was very forthcoming about the down side to being an underwater welder even though he admitted the pay was great.
Basically the term "underwater welding" refers both to wet welding where the welding is actually done with special electrodes in the water, as well as what is known as Dry underwater welding where the welding is done in a special habitat called a hyperbaric chamber. ( a chamber that pumps water out and is pressurized just like a submarine).
Divers even sometimes spend days under water traveling back and forth from a special sleeping quarters chamber, to the welding habitat.
After staying down for several days, divers have to de-pressurize to avoid getting the bends. Sound like fun?
Wet welding is the most common underwater welding that is done and it requires the use of special waterproof electrodes and electrode holders.
One question that is always asked about underwater welding is ..What about getting shocked?
Well, underwater welders will tell you that even though welding current is not as dangerous as household current, a leak in the insulated rubber gloves can shock the welder to the point where he tastes the metal fillings in his teeth...Damn!
Wet welds are done by a diver in a wet suit. It is dangerous and difficult and requires a lot of training and practice to do. Dangerous creatures like sharks and barracudas are always a threat. Even the surges of the ocean waves are an obstacle to overcome.
Welders often guide the wet electrode with their fingers to get as much feel and stability as possible and to remain steady when the ocean current tries to move them.
Dry welding is done in a chamber where the water is pumped out and an atmosphere is pumped in.Unlike wet welding where stick welding electrodes are used, Tig welding can also be done in the underwater welder's special welding habitat.
The dry welding that is done in the habitat is just like any other welding except that it is done in tight quarters and the underwater welder divers actually breathe a special air atmosphere in the chamber.