A welder fuses metal pieces together using heat and tools to assemble structures or repair damaged components. Key duties include interpreting blueprints, setting up welding equipment, and performing the actual welding using various techniques like MIG or TIG. Welders must also inspect their work for defects, maintain safety standards, and often perform grinding and cutting as part of the job. Duties include interpreting blueprints, setting up welding equipment, and performing the actual welding using various techniques like MIG or TIG. Welders must also inspect their work for defects, maintain safety standards, and often perform grinding and cutting as part of the job.