FAA Advisory Circular 43.13-1B
Acceptable Methods, Techniques, and Practices
Aircraft Inspection and Repair
AC 43.13-1B | 4. Metal Structure, Welding, and Brazing | 6. Welding and Brazing Safety | 4-112. Fire and Explosion Safety
9/27/01
AC 43.13-1B CHG 1
SECTION 6. WELDING AND BRAZING SAFETY
4-111. GENERAL. A number of inherent
hazards exist in the use of oxy-fuel welding
and cutting apparatus. It is necessary that
proper safety and operating procedures are un
derstood. A thorough understanding of the
proper safety and operating procedures mini
mizes the hazards involved and adds to the
pleasure and efficiency of your work.
4-112. FIRE AND EXPLOSION SAFETY.
Fires occur in welding areas because flamma
bles are left where they can be ignited by
welding sparks or gas welding flames. Before
welding, clear the welding area of all flamma
bles such as rags, paper, wood, paint cans, sol
vent, and trash containers. Do not weld in ar
eas where flammables are present.
a. Unless absolutely necessary, never
weld any tank or radiator that has had a flam
mable in it, including gasoline, av-gas, motor
oil, hydraulic fluid, or any other liquid that
could ignite if the vapor and temperature reach
a flashpoint. Explosions often occur when
empty tanks are being welded or cut open with
a torch.
b. If welding such tanks or radiator cool
ers is absolutely necessary, the tank must first
be washed with a caustic-based, water-soluble
liquid, rinsed with plenty of clear water, and
then dried. Before welding, the tank or con
tainer should be thoroughly purged with argon,
or other inert gas, while the welding is in proc
ess.
4-113. WELDING WORK AREA.
a. The work area must have a fireproof
floor, concrete floors are recommend.
b. Use heat-resistant shields to protect
nearby walls or unprotected flooring from
sparks and hot metal.
c. Maintain an adequate suction ventila-
tion system to prevent the concentration of
oxygen/fuel gas, flammable gases, and/or toxic
fumes. It is important to remember that oxy
gen will not burn. The presence of oxygen,
however, serves to accelerate combustion, and
causes materials to burn with great intensity.
CAUTION: Oil and grease in the
presence of oxygen can ignite and
burn violently.
d. A completely clean welding shop area
with white walls, ceiling, and floor; and with
plenty of light, is better for welding. The bet
ter the lighting conditions, the easier it is to see
the weld puddle and make excellent aircraft-
quality welds.
e. During oxy-fuel processes use work
benches or tables with fireproof tops. Fire
bricks commonly top these surfaces and sup
port the work.
f. Chain or otherwise secure oxygen and
fuel gas cylinders to a wall, bench, post, cylin
der cart, etc. This will protect them from fal
ling and hold them upright.
4-114. FIRE PROTECTION. Practice fire
prevention techniques whenever oxy-fuel op
erations are in progress. Simple precautions
prevent most fires, and minimize damage in
the event a fire does occur. Always practice
the following rules and safety procedures.
Par 4-111
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