TM 9-2320-280-34
g. Repair by Patching. Most body panel damage that exceeds the limits of negligible damage may be
repaired by patching. This procedure involves removal of damaged area (1) and application of a patch (2) to
cover the area (1). The damaged area is prepared by removal of the damage followed by rounding or
smoothing of all corners and edges. This helps to assure that cracks will not spread into undamaged areas. In
the case of a large crack (4), it may be desirable to stop-drill the crack (4), rather than cut out a portion of the
panel (5) or structural member. Repair is completed by applying a large overlapping patch (3) over the area
that was damaged. The overlap must be sufficient to allow the observance of proper rivet edge distance (6)
(para. 22-8.c). Large areas of damage are best repaired using a patch that is attached with multiple rows of
rivets (para. 22-8.c).
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