Cornwell Tools MIG 250MGS, Руководство пользователя

Страница: 23 / 28

Page of 28 23
1. The BURN-THROUGH METHOD welds two overlapped pieces of metal together by burning
through the top piece and into the bottom piece. With the burn-through method, larger wire
diameters tend to work better than smaller diameters. Wire diameters that tend to work best, with
the burn-through method are 0.035 inch self-shielding flux-core wire. Do not use 0.030 inch
self-shielding flux core wires when using the burn-through method unless the metal is VERY thin or
excessive filler metal build-up and minimal penetration is acceptable. Always select the HIGH heat
setting with the burn-through method and tune in the wire speed prior to making a spot weld.
2. The PUNCH AND FILL METHOD produces a weld with the most finished appearance of the three
spot weld methods. In this method, a hole is punched or drilled into the top piece of metal and the
arc is directed through the hole to penetrate into the bottom piece. The puddle is allowed to fill 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 tune in the 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
tune in the wire speed as if you were welding the same thickness material with a continuous bead.
8.6 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 piece completely perpendicular to and about 1/4 inch off the work piece.
4. Pull the trigger on the torch and release it when it appears that the desired penetration has been
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 work piece at desired locations.