Tweco FP-90 - Manual (Page 23)

2. The punch and fill method produces a weld with the most finished appearance. In this method, a hole is
punched or drilled into the top piece of metal. The arc is directed through this hole to penetrate into the bot-
tom piece. The puddle fills up the hole leaving a spot weld that is smooth and flush with the surface of the
top piece. Select the wire diameter, heat setting and wire speed as if you were welding the same thickness
material with a continuous bead.
3. The lap spot method directs the welding arc to penetrate the bottom and top pieces, at the same time, right
along each side of the lap joint seam. Select the wire diameter, heat setting and wire speed as if you were
welding the same thickness material with a continuous bead.
SPOT WELDING INSTRUCTIONS
1. Select the wire diameter and heat setting recommended above for the method of spot welding you intend to
use.
2. Tune in the wire speed as if you were going to make a continuous weld.
3. Hold the nozzle completely perpendicular to and about ⁄ inch off the workpiece.
4. Pull the trigger on the gun. Release it when it appears that the desired penetration is achieved.
5. Make practice spot welds on scrap metal, varying the length of time you hold the trigger, until a desired
spot weld is made.
6. Make spot welds on the actual workpiece at desired locations.
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