TM 5-5420-278-24&P
0068 00
0068 00-2
RAMP BAY AND INTERIOR BAY CRACK REPAIR (Contd)
NOTE
If there are several cracks or holes within a damaged area, repair
must be performed by removing damaged area and welding in a
new sheet metal plate, P/N AMS-QQ-A-25014, NSN 9535-00-
003-6946.
IRB bays are made from corus aluminum ABKANTGUETE
6061-T651 749572.
PREPARATION
1.
Position ponton (1) so crack (2) is face-up for welding.
2.
Grind area and find ends of crack (2).
3.
Drill a hole (4) at ends of crack (2) in order to prevent enlargement of crack (2). Use a drill with
diameter corresponding to half the plate thickness.
NOTE
If crack is open 0.098 in. (2.5 mm) or more, and additional
permanent weld pool retainer is required. For this retainer, use a
metal strip 1 in. (25.4 mm) or more in width and with a milled
groove.
4.
Mill or grind a V-seam along crack (2) with a groove angle of 70 degrees.
5.
Clean area to be welded with a stainless steel wire brush.
WELDING
1.
If necessary, insert and tack weld retainer (3) (refer to TC 9-237).
2.
Finish weld area to be welded root, filler, and final pass welds (refer to TC 9-237).
3.
Perform ponton leak test (WP 0059 00). Reweld if necessary.
4.
Clean, treat, and paint area per MIL-T-704 TYPE B.
5.
Remove leak detector kit (WP 0059 00).
6.
Connect outer ponton and inner ponton (WP 0023 00 or WP 0042 00), if separated.
7.
Install ramp bay or interior bay on transporter (TM 5-542-278-10).