PREVENTIVE MAINTENANCE CHECKS AND SERVICES (PMCS), INCLUDING
LUBRICATION INSTRUCTIONS Continued
7) Make sure welding area has plenty of fresh air without being drafty. remove all toxic and
8) Make sure all electrical and gas connections are tight.
9) Do not touch any metal in welding area with bare hands. Aluminum does not change color when hot.
10) Do not weld in the fuel compartment where sealing compound has been applied.
11) Use a welding screen to protect personnel from arc flash.
GENERAL WELDING PROCEDURES.
BASIC WELDING REPAIRS. Repairs are made on 5083 aluminum alloy using the MIG (Gas Metal Arc)
CONTRACTION AND EXPANSION. Aluminum welds contract about 6 percent in volume when they
become solid. Welding at slow speed may cause too much heating of the area around the weld. This will cause
the metal to expand too much or melt. It well then cause cracking upon cooling.
FILLER WIRE. Always use clean wire. Filler wire polluted by grease, oil, dust, or shop fumes causes porous
welds. After welding, cover wire to prevent pollution. Store covered wire in warm, dry place.
CLEANING OF WELDED SURFACES. Remove oxides, grease, oil films, paint, and all foreign matter from
joint before welding. Wipe edges of joint with a clean cloth dipped in cleaning compound, and let dry before
welding. Sand with disk sander, or brush surface with clean stainless steel wire brush to remove oxide. Clean
up weld area and touch up paint all bare metal (see TM 43-0139).
FIT-UP AND TACKING. Good joint fit-up makes welding easier, saves filler wire and gas, and helps get
higher quality welds. You must tack weld to hold the joint members in place if you dont have jigs. Tack welds
should be small, neat, and placed right to keep parts lined up before and during welding.
WELDING UNEQUAL SECTIONS. When welding unequal sections, direct arc against heavier piece to fuse
the two edges evenly. Watch weld pool edge rather that arc to ensure weld pool edges fuse right.
MULTI-PASS WELDING. Make sure edges of weld pool fuse right. Watch weld pool rather than arc. Any
oscillating of weaving motion should be slight, smooth, and slow. Brush material with clean stainless steel
wire brush after each pass. On small weldments, lower amperage slightly after each pass if welding members
become too hot.
Heat distortion during welding will damage aluminum castings. Do not attempt to repair
aluminum castings by welding.
FINAL DRIVE CASTING. Welding in final drive aluminum casting is not authorized. Do not attempt to
weld on final drive housing assembly.