Tweco 300 MST Arcmaster - Manual (Page 8)

2
ARCMASTER 300 MST
3. Use protective screens or barriers to protect others from flash
and glare; warn others not to watch the arc.
4. Wear protective clothing made from durable, flame-resistant
material (wool and leather) and foot protection.
5. Use approved ear plugs or ear muffs if noise level is high.
WARNING
FUMES AND GASES can be hazardous to your health.
Welding produces fumes and gases. Breathing these
fumes and gases can be hazardous to your health.
1. Keep your head out of the fumes. Do not breath the fumes.
2. If inside, ventilate the area and/or use exhaust at the arc to remove
welding fumes and gases.
3. If ventilation is poor, use an approved air-supplied respirator.
4. Read the Material Safety Data Sheets (MSDSs) and the
manufacturer’s instruction for metals, consumables, coatings, and
cleaners.
5. Work in a confined space only if it is well ventilated, or while
wearing an air-supplied respirator. Shielding gases used for
welding can displace air causing injury or death. Be sure the
breathing air is safe.
6. Do not weld in locations near degreasing, cleaning, or spraying
operations. The heat and rays of the arc can react with vapors to
form highly toxic and irritating gases.
7. Do not weld on coated metals, such as galvanized, lead, or
cadmium plated steel, unless the coating is removed from the
weld area, the area is well ventilated, and if necessary, while
wearing an air-supplied respirator. The coatings and any metals
containing these elements can give off toxic fumes if welded.
WARNING
WELDING can cause fire or explosion.
Sparks and spatter fly off from the welding arc. The flying
sparks and hot metal, weld spatter, hot workpiece, and
hot equipment can cause fires and burns. Accidental
contact of electrode or welding wire to metal objects
can cause sparks, overheating, or fire.
1. Protect yourself and others from flying sparks and hot metal.
2. Do not weld where flying sparks can strike flammable material.
3. Remove all flammables within 35 ft (10.7 m) of the welding arc.
If this is not possible, tightly cover them with approved covers.
4. Be alert that welding sparks and hot materials from welding can
easily go through small cracks and openings to adjacent areas.
5. Watch for fire, and keep a fire extinguisher nearby.
6. Be aware that welding on a ceiling, floor, bulkhead, or partition
can cause fire on the hidden side.
7. Do not weld on closed containers such as tanks or drums.
8. Connect work cable to the work as close to the welding area as
practical to prevent welding current from traveling long, possibly
unknown paths and causing electric shock and fire hazards.
9. Do not use welder to thaw frozen pipes.
10. Remove stick electrode from holder or cut off welding wire at
contact tip when not in use.
Welding or cutting Electrode Size Filter Welding or cutting Electrode Size Filter
Torch soldering 2 Gas metal-arc
Torch brazing 3 or 4 Non-ferrous base metal All 11
Oxygen Cutting Ferrous base metal All 12
Light Under 1 in., 25 mm 3 or 4 Gas tungsten arc welding All 12
Medium 1 to 6 in., 25-150 mm 4 or 5 (TIG) All 12
Heavy Over 6 in., 150 mm 5 or 6 Atomic hydrogen welding All 12
Gas welding Carbon arc welding All 12
Light Under 1/8 in., 3 mm 4 or 5 Plasma arc welding
Medium 1/8 to 1/2 in., 3-12 mm 5 or 6 Carbon arc air gouging
Heavy Over 1/2 in., 12 mm 6 or 8 Light 12
Shielded metal-arc Under 5/32 in., 4 mm 10 Heavy 14
5/32 to 1/4 in., 12 Plasma arc cutting
Over 1/4 in., 6.4 mm 14 Light Under 300 Amp 9
Medium 300 to 400 Amp 12
Heavy Over 400 Amp 14
Eye protection filter shade selector for welding or cutting
(goggles or helmet), from AWS A6.2-73.