Filler Metals

TM 10-3930-633-34

essential. However, a breeze directed on the arc

2-15. Safety

can destroy the gas shield around the arc.

a. Protect-o-seal (anti-flashback) fuel tank cap

b. Never use oxygen for ventilation, or as air

must be in place before grinding, burning, or

jet.

welding. Preferred procedure is to empty the fuel

c. Avoid all welding or cutting in paint booths,

tank and purge with CO2.

around dip tanks, decreasing, or other naturally

CAUTION

hazardous areas.

Before attaching welding ground cable to

d. Excessive or continued breathing of smoke,

the machine, be sure that the alternator

toxic fumes, or dust is injurious. Use respirator in

harness and/ or battery cables are

addition to ventilation under severe conditions.

disconnected. This is to prevent burning

e. Keep all air in work area moving toward

out the diodes in the alternator because

exhaust system.

of reverse polarity.

2-18. Filler Metals

b. Always wear helmet, asbestos gloves,

suitable shoes, apron, or other suitably protective

a. All stick electrodes for subject contract

clothing when welding.

joints must be low hydrogen coated (herein called

c. Clothing should be heavy, free from oil or

L.H.). L.H. electrode E-7018 (AWS Class.) is

grease. Pockets and cuffs should be protected

recommended, except when specially noted.

against sparks and slag.

b. E-7019, E-8018, E-9018, E-10018, E-11018

d. Portable grinders should have proper wheel

have AC-DC polarity, reversing current, with a

guards. Operator s h o u l d be equipped with

coating of low hydrogen iron powder.

goggles or safety shield.

c. L.H. electrodes are supplied from the vendor

e. Always use proper torch, tip, electrode, and

in hermetically sealed containers, and must have

holder for the job.

storage care normal to their type. If containers

f. Maintain good welding cables, preferably

have been opened for electrodes to become ex-

protected by loom.

p o s e d to normal (and above) atmospheric

g. Ground cables to work, never to house

humidity, the electrodes should be oven baked at

systems, hoists, chain falls, etc. Attach welding

700 F. for 1 hour minimum.

ground cable to one of the two members being

d. L. H. electrodes which have been in water

joined. Do not run current through bearings or

should be scrapped.

wear surfaces.

e. Remove only enough electrodes from the

h. Welding area should be clean and dry.

container to perform the immediate job. Open

i. Oxygen should never be used as compressed

containers should be stored in heated storage

air, in cleaning or drying operations.

containers held at 2000 to 300 F.

j. Do not use rope to suspend work when

f. The manufacturer employs little or no TIG

flame-cutting, grinding, or welding.

production welding at the factory.

g. The manufacturer employs MIG welding

2-16. Fire Protection

extensively in production welding. Due to its

a. Remove work from hazardous area before

nature however, the welding instruction herein

cutting or welding. If this is not possible, remove

(repair, as opposed to production welding) will

flammable material from work area, or cover with

deal only with stick electrodes. The precautionary

flame arresting material.

and preparation instruction herein applies also to

b. Correct those conditions where sparks or

MIG or TIG welding.

slag can travel into combustible materials.

2-19. Preparation

c. Keep oil or grease separated from oxygen.

This combination is explosive if ignited.

a. In natural ambient temperatures of 60 F or

d. Do not allow clothing to collect pure

less, the machine (or component) should be "room

oxygen. In this concentrated or oxygen-enriched

soaked" overnight in 70 F (+) to equate a

condition, materials burn violently.

preheat. If this is impossible, the weld zone (area

e. Keep fully charged fire extinguishers

6" to 10" each side) should be preheated to a

nearby. Employ standby assistant with ex-

minimum of 100 F. b e f o r e welding. This

tinguisher during unavoidable hazardous con-

minimum temperature should be maintained on

ditions.

the heat zone of each joint until that joint is

completed.

2-17. Ventilation

b. Thermal sticks may be used to check these

a. Fans on welders and work help to assure

weld heat-affected zones. Timpil sticks are

good ventilation. Adequate exhaust fans are

2-11