Inhoudsopgave
Advertenties
Beschikbare talen
Beschikbare talen
ENG
to thoroughly chip and brush the slag off each completed weld bead before
making another pass or the next pass will be of poor quality.
Fillet Weld Joints. Most fillet weld joints, on metals of moderate to heavy
thickness, will require multiple pass welds to produce strong joint. The illus-
trations in Figure 19 show the sequence of laying multiple pass beads into a T
fillet joint and a lap fillet joint.
Spot welding
There are three methods of spot welding: Burn-Through, Punch and Fill, and
Lap. Each has advantages and disadvantages depending on the specific ap-
plication as well as personal preference.
1. The BURN-THROUGH METHOD welds two overlapped pieces of metal to-
gether 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 .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 pun-
ched 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.
59
Advertenties
Inhoudsopgave
