Weld ocean-going hulls and hatches together on massive ships.
Tends equipment that forms and prepares aperture masks and display screens for oscilloscope and television picture tubes: Feeds specified sections of sensitized steel between plates in photographic printing chase to flatten sheet to specification. Sets timer for specified exposure and turns on heliarc lamp to imprint pattern of aperture mask from photographic plate onto steel. Verifies alignment of plates, using microscope. Tends furnace that blackens aperture masks and rings. Feeds mask through series of rollers that flatten mask. Positions mask on bed of forming press and lowers die to form mask. Tends processing equipment to clean, dry, and coat phosphor on inside face of display screen. Positions aperture mask and screen on fixture over time-cycled light source to print color-emitting dots on phosphor coating. Starts cycle to expose coating to light through mask aperture. Marks mating screen and aperture mask with matching numbers for future assembly. Fastens screen in holder on conveyor that carries screen through equipment that develops exposed phosphor, removes unexposed phosphor, and dries screen. May be designated according to process as Aperture-Mask Etcher; Mask Former; Screener.