Welder

A welder is a workman who is specialized in combining materials such as metal or plastic including the use of pressure and heat.

In 2151 a crewman served as welder in a section of Enterprise, moments after the ship was damaged by an unidentified alien vessel. 

In 2154 a crewman of the Enterprise served as welder in the team which prepared a shuttlepod for a mission to the surface of Vulcan. 

In 2373, one of the Maquis refugees on Marva IV was welding. 

In 2375 one of the Bajorans who followed Gul Dukat and the pah-wraiths was welding on the second level of Terok Nor's promenade.