TM 9-2320-363-34-2
1.
LOADS ARE APPLIED THRU JOINT TO FASTENERS HOLDING JOINT TOGETHER. THESE LOADS
ARE APPLIED TO FASTENERS IN FORM OF SHEAR LOADS OR TENSION LOADS. IF LOAD IS
PERPENDICULR TO AXIS OF FASTENERS. FASTENER IS LOADED IN SHEAR. FASTENER IS
LOADED IN TENSION WHEN LOAD IS ALONG AXIS OF FASTENER CAUSING PULL ON EACH
END OF FASTENER.
2.
RIVETS (1) ARE DESIGNED TO BE LOADED IN SHEAR. DO NOT CREATE NEW JOINTS DURING
REPAIRS WHICH CAUSE RIVETS TO BE USED IN TENSION APPLICATION. BOLTS (2) SHOULD
BE USED FOR TENSION APPLICATIONS OR SUBSTITUTED FOR RIVETS IN VERY HIGH-SHEAR
LOAD APPLICATIONS.
Repair Parts Preparation
1.
PAINT REPAIR PARTS OR PATCHES WITH EPOXY PRIMER BEFORE INSTALLATION.
2.
APPLY SEALING COMPOUND TO MATING SURFACES TO PREVENT CORROSION.
3.
INSTALL PART OR PATCH AS DETAILED IN REPAIR BY PATCHING AND REPAIR BY INSERTION,
BELOW.
4.
PAINT REPAIRED AREA WITH EPOXY PRIMER.
5.
PAINT REPAIRED AREA WITH POLYURETHANE, AS REQUIRED.
Repair Negligible Damage
1.
2.
3.
NEGLIGIBLE CRACKS, AS DEFINED IN CLASSIFICATION, ABOVE, ARE REPAIRED BY DRILLING
SMALL HOLE AT EACH END OF CRACK TO STOP CRACK PROPAGATION. THIS IS CALLED
STOP DRILLING. TABLE 8 GIVES PROPER DRILL SIZES FOR STOP DRILLING CRACKS.
NEGLIGIBLE HOLES ARE REPAIRED BY ROUNDING AND SMOOTHING EDGES OF HOLE TO
ALLEVIATE STRESS RISERS CAUSED BY SHARP NOTCHES.
C A U T I O N
Never use heat to reform parts. Heat greatly reduces part strength.
SMALL DENTS AND DISTORTED AREAS MAY BE REPAIRED BY BENDING OR HAMMERING AS
LONG AS OPERATION DOES NOT CAUSE MATERIALS TO CRACK OR TEAR. SHARP BENDS
SHOULD NOT BE ATTEMPTED.
Table 8. Stop Drill Sizes for Negligible Cracks
I
Sheet Thickness (In.)
I Minimum Stop Drill Size No. I
I
0-0.032
I
40
0.033 and thicker
30
I
22-25
