Figure 7-24.Horizontal welding angles.
Figure 7-25.Tack-weld to hold the tee joint elements in place.
An inexperienced welder usually finds the horizon-
tal position of arc welding difficult, at least until he has
developed a fair degree of skill in applying the proper
technique. The primary difficulty is that in this position
you have no shoulder of previously deposited weld
metal to hold the molten metal.
In horizontal welding, position the electrode so that
it points upward at a 5- to 10-degree angle in conjunction
with a 20-degree travel angle (fig. 7-24). Use a narrow
weaving motion in laying the bead. This weaving mo-
tion distributes the heat evenly, reducing the tendency
of the molten puddle to sag. You should use the shortest
arc length possible, and when the force of the arc under-
cuts the plate at the top of the bead, lower the electrode
holder a little to increase the upward angle.
Figure 7-26.Position of electrode and fusion area of fillet weld
on a tee joint.
As you move in and out of the crater, pause slightly
each time you return. This keeps the crater small and the
bead has less tendency to sag.
Horizontal-position welding can be used on most
types of joints. The most common types of joints it is
used on are tee joints, lap joints, and butt joints.
TEE JOINTS. When you make tee joints in the
horizontal position, the two plates are at right angles to
each other in the form of an inverted T. The edge of the
vertical plate may be tack-welded to the surface of the
horizontal plate, as shown in figure 7-25.
A fillet weld is used in making the tee joint, and a
short arc is necessary to provide good fusion at the root
and along the legs of the weld (fig. 7-26, view A). Hold
the electrode at an angle of 45 degrees to the two plate
surfaces (fig. 7-26, view B) with an incline of approxi-
mately 15 degrees in the direction of welding.
When practical, weld light plates with a fillet weld
in one pass with little or no weaving of the electrode.
Welding of heavier plates may require two or more
passes in which the second pass or layer is made with a
semicircular weaving motion, as shown in figure 7-27.
To ensure good fusion and the prevention of undercut-
ting, you should make a slight pause at the end of each
weave or oscillation.
For fillet-welded tee joints on 1/2-inch plate or
heavier, deposit stringer beads in the sequence shown in