Underwater Welding Arcs

**Underwater welding arcs **do not behave the same as on the surface and the activity of the gas bubble is particularly important to successful completion of the underwater weld. When the arc is struck, the combustion of the electrode and the detachment of water creates a gas bubble or envelope. As the pressure within the bubble increases, it is forced to leave the arc and meet with the surrounding water while another bubble forms to take its place. Then, as this pressure head becomes greater than the capillary force, the bubble breaks down. Therefore, if the electrode is too far from the work, the weld will be destroyed as the gases explode and blow through. If the travel speed is too slow, the bubble will collapse around the weld and destroy the possibility of producing an effective weld.

NOTE
Thick, gauntlet-type rubber gloves in good condition, worn over a pair of playtex-type gloves afford the best protection against electrical shock. They should be secured at the wrist to prevent slag from getting inside the glove. When working in cold water, wetsuit gloves in good condition, worn over surgical gloves are equally effective.