GENERAL WELDING MAINTENANCE (CONT).
Use the brush within 1.5 inches (38 mm) on both sides of repair area.
(b) Once the galvanizing starts to melt, use a stainless steel wire brush to remove paint,
primer and galvanizing.
(a) Protect the area around the weld repair with masking tape (about 1 inch on each side
of the anticipated weld deposit). This will protect the other areas of the CARC finish
not being repaired.
(b) Use sandblaster to remove paint, primer and galvanizing.
Option Three. Use surface grinder (hand grinder) to remove paint, primer and galvanizing
within one inch on either side of the anticipated weld deposit.
Galvanized Coating Replacement. To replace the galvanized coating, use Zinc Stick
(95% zinc, 5% tin with flux) that will melt at less than 750F (398C), followed by a primer and top coat (CARC
paint). This is recommended repair for galvanized CROPs prior to primer and CARC paint. If the spray metalizing
(Zinc) method is available, it is the preferred method. The galvanizing method is in accordance with ASTM A780
and the thickness will be in accordance with ASTM E376. If there are questions about the repair method OR the
application of one of these processes, contact the American Galvanizers Association at 1-800-468-7732 or Mr.
George Shaw at the U.S. Army Tank-Automotive and Armaments Command's Materials & Coating Group, 1-800-
325-2920, extension 45083.
Do not weld the CROP while on trailer or truck or damage to equipment may result.
Welding on the CROP must be performed off the trailer or truck. Different areas of the
CROP require different weld electrodes and preheat. Use the following guidelines to deter-
mine the correct weld and/or preheat. The bail bar center wear plate should be accom-
plished using 300F (149C) preheat and ER110S-1 with gas metal arc welding (wire feed
welder with argon and oxygen shielding gas) or E11018-M with submerged metal arc
welding (E11018-M stick electrode and arc welder). All other areas of the CROP should
be welded using ER70S-6 welding wire. The following applies:
Bail Bar Center Wear Repair
Pin Support Plate to End
Structure Assembly Tubes
Pin Block to Main Beams
D-Ring Bar to Side Beam
Bracing Mechanism Nut to Side Beam
Areas not listed above do not require preheat.