FAA Advisory Circular 43.13-1B
Acceptable Methods, Techniques, and Practices
Aircraft Inspection and Repair
AC 43.13-1B | 6. Corrosion, Inspection, and Protection | 10. Ferrous Metals | 6-167. Example of Removing Corrosion From Ferrous Metals
AC 43.13-1B
9/8/98
6-167. EXAMPLE OF REMOVING
CORROSION FROM FERROUS MET-
ALS. If possible, corroded steel parts should
be removed from the aircraft. When impracti
cal to remove the part, follow the procedure
below.
g. Inspect the area for remaining corro
sion. Repeat procedure if any corrosion re
mains and the structural integrity of the part is
not in danger, and the part meets the rework
limits established by the manufacturer or FAA
authorized DER.
a. Prepare the area for rework.
b. Positively identify the metal as steel
and establish its heat-treated value.
h. Fair depressions using a blend ratio
of 20:1. Clean area using 240-grit paper.
Smooth area with 300-grit paper and give final
polish with 400-grit paper.
c. Clean the area and strip paint if re
quired.
NOTE: Use of acid-based strippers,
chemical removers, or chemical con-
version coatings are not permitted on
steel parts without engineering
authorization.
d. Determine extent of corrosion damage.
e. Remove residual corrosion by hand
sanding with mild abrasive mats, cloths, and
papers, such as fine aluminum oxide grit.
f. Remove heavy deposits of corrosion
products by approved mechanical methods for
that particular form of steel and/or stainless
steel.
i. Determine depth of faired depression
to ensure that rework limits have not been ex
ceeded.
j. Clean reworked area with dry cleaning
solvent. Do not use kerosene.
k. Apply protective finish or specific or
ganic finish as required.
NOTE: Steel surfaces are highly-
reactive immediately following corro-
sion removal; consequently, primer
coats should be applied within 1 hour
after sanding.
l. Remove masking and protective cover
ings.
6-168.6-178. [RESERVED.]
Page 6-36
Par 6-167