P2002 Sierra
SECTION B
M A I N T E N A N C E M A N U A L
pag.
B-10
2
st
Edition, April 22
th
, 2008
INSPECTION & SERVICING
8
CORROSION PREVENTION
It is important to keep the aircraft clean and to remove any collection of
corrosive agents such as oil, grease, dregs and other foreign matter. To
avoid damage to finish, do not use polishing detergents.
Original or equivalent corrosion prevention must be re-applied after any
alteration or repair.
If any trace of corrosion is detected it should be removed as soon as
possible and part should be immediately treated to prevent further corro-
sion.
(a) For steel parts, with the exception of highly stressed components or
stainless steel, it is possible to use abrasives, power brushes, steel brushes
if operated manually and steel wool.
Removing corrosion by products from highly stressed steel components
(main gear steel spring) requires particular care.
(b) For aluminum parts, treatment consists in mechanically removing
as much as possible corrosion by products, applying corrosion inhibitor
and replacing original finish.
Steel wool, emery or steel brushes (unless stainless steel) along with
other highly abrasive material should not be used since steel or emery par-
ticles become embedded in the softer material causing corrosion.
After cleaning surface corrosion, parts must be treated with an anti-
corrosion finish prepared as follows: 4 liter solution containing 10%
cromic acid with 20 drops of battery electrolyte. Accurate brushing with a
sturdy fiber brush will rid of most of the corrosion and insure that the anti-
corrosion agent will penetrate completely in the cracks.
Leave the cromic acid solution on the part for at least five minutes and
then remove excess with water or a damp cloth. Apply protective finish the
same day in which treatment begins.