Lincoln Electric IM724 manual Welding In The Vertical Position, Penetration, Fillet Welds

B-10 LEARNING TO WELD B-10

FIGURE B.12

Penetration

Unless a weld penetrates close to 100% of the metal thickness, a butt weld will be weaker than the material welded together. In the example shown in Figure B.13, the total weld is only half the thickness of the material thus the weld is only approximately half as strong as the metal.

45°

FIGURE B.15

Welding In The Vertical Position

Welding in the vertical position can be done either ver- tical-up or vertical-down. Vertical-up is used whenever

alarger, stronger weld is desired. Vertical-down is used primarily on sheet metal 5/32” (3.9 mm) and under for fast, low penetrating welds.

FIGURE B.13

FIGURE B.14

In the example shown in Figure B.14, the joint has been welded so that 100% penetration could be achieved. The weld, if properly made, is as strong as or stronger than the original metal.

Fillet Welds

When welding fillet welds, it is very important to hold the wire electrode at a 45° angle between the two sides or the metal will not distribute itself evenly. The gun nozzle is generally formed at an angle to facilitate this. See Figure B.15.

WARNING

Use of this unit on thicker materials than recom- mended may result in poor welds. The welds may “look” good, but may just be “sitting” on top, of the plate. This is called “Cold Casting” and will result in weld failure.

Vertical-up And Overhead Welding

The problem, when welding vertical-up, is to put the molten metal where it is wanted and make it stay there. If too much molten metal is deposited, gravity will pull it downwards and make it “drip”. Therefore, a certain technique has to be followed.

When welding out-of-position, run stringer beads. Don’t whip, break the arc, move out of the puddle, or move too fast in any direction. Use Wire Feed Speed (WFS) in the low portion of the range. The general technique and proper gun angle is illustrated in Figure B.16.

Generally, keep the electrode nearly perpendicular to the joint as illustrated. The maximum angle above per- pendicular may be required if porosity becomes a problem.

SP-135T