Chapter 29 Shielded Metal Arc Welding 801
Copyright Goodheart-Willcox Co., Inc.
Position the welding machine close to the work to
reduce tripping hazards caused by welding leads lying
across fl oors. Pick up loose electrodes and electrode
stubs left after welding to prevent slipping hazards on
hard concrete fl oors.
When required to weld on objects close to a
concrete fl oor, use a shield. The pores of a concrete
fl oor contain water that can quickly turn to steam,
resulting in small explosions in the surface of the
concrete. Welding on containers should be avoided,
since the expansion of gases within the container can
result in violent reactions.
Good ventilation is critical for welder safety.
Dedicated ventilation systems are excellent for
removing contaminants from the air, but they can
be noisy. See Figure 29-43. Working in open areas or
opening large bay doors to increase ventilation when
welding is a quieter alternative.
Personal Protective Equipment
Proper personal protective equipment (PPE) is
essential. The PPE worn should be appropriate for all
hazards that may be present.
A welding helmet that protects the entire face
is required. Handheld observer’s shields are for
supervision purposes only and offer inadequate
protection for welding. Welding helmets should have
a minimum of a #10 shade or fi lter lens and a clear
protective plastic cover lens in front, Figure 29-44. The
shades available for arc welding fi lter lenses range in
protection from #9 to #14. A #9 lens is for limited use in
special situations only, and a #14 shaded lens is so dark
that its use may be detrimental to the quality of welds
Goodheart-Willcox Publisher
Figure 29-42. Welding curtains protect bystanders
from the hazardous light emitted by the welding
process.
Goodheart-Willcox Publisher
Figure 29-43. An exhaust apparatus for welding
should be placed as near as practical to the actual
welding arc.
Goodheart-Willcox Publisher
Figure 29-44. Many styles of welding helmets are available to meet the different needs
and personal preferences of welders.