FAA Advisory Circular 43.13-1B
Acceptable Methods, Techniques, and Practices
Aircraft Inspection and Repair
AC 43.13-1B | 6. Corrosion, Inspection, and Protection | 7. Basic Corrosion Removal Techiques | 6-118. Standard Methods
9/8/98
AC 43.13-1B
FIGURE 6-14. Typical example of acceptable cleanup of corrosion pits.
a. Materials. Do not use harmful clean
ing, polishing, brightening, or paint-removing
materials. Use only those compounds that
conform to existing government or established
industry specifications or that have been spe
cifically recommended by the aircraft manu
facturer. Observe the product manufacturer’s
recommendations concerning use.
b. Chemical Cleaners. Chemicals must
be used with great care in cleaning assembled
aircraft. The danger of entrapping corrosive
materials in faying surfaces and crevices
counteracts any advantages in their speed and
effectiveness. Use materials that are relatively
neutral and easy to remove.
c. Removal of spilled battery acid. The
battery, battery cover, battery box and adjacent
areas will be corroded if battery acid spills
onto them. To clean spilled battery acid, brush
off any salt residue and sponge the area with
fresh water. For lead-acid batteries, sponge the
area with a solution of 6 ounces of sodium
bicarbonate (baking soda) per gallon of fresh
water. Apply generously until bubbling stops
and let solution stay on the area for 5 to
6 minutes, but do not allow it to dry. For
nickel-cadmium batteries, sponge the area with
a solution of 6 ounces of monobasic sodium
phosphate per gallon of fresh water. Sponge
area again with clean fresh water and dry sur
face with compressed air or clean wiping
cloths.
6-118. STANDARD METHODS. Several
standard mechanical and chemical methods are
available for corrosion removal. Mechanical
methods include hand sanding using abrasive
mat, abrasive paper, or metal wool; and pow
ered mechanical sanding, grinding, and buff
ing, using abrasive mat, grinding wheels,
sanding discs, and abrasive rubber mats. The
method used depends upon the metal and de
gree of corrosion. The removal method to use
on each metal for each particular degree of
corrosion is outlined in the following section.
Par 6-117
Page 6-23