SERVICE MANUAL & ICA
8750 AMPHIBIAN/SEAPLANE FLOATS ON CESSNA 208/208B
P/N 1005723 Doc. No. W8750-24-01
Page 84 of 104
Revision C
9.1 CORROSION REMOVAL
Corrosion is usually detected visually, which
is why Wipaire strongly recommends the
previous cleaning and inspection procedures.
It can appear as a white or pale green powder,
discoloration of the metal surface, or bubbles
and blisters under the surface of the paint.
Light corrosion is removed by gentle sanding
or chromic acid. Moderate and severe
corrosion (blistering, flaking and pitting) can
be removed by heavier sanding or grinding.
Reinforcement or replacement of affected
areas may be necessary if there is critical loss
of strength in parent metal and depends on
location and other factors.
Pylon before repair…
Pylon Fully Repaired
After removing the corrosion, restore the area
to the original finish, like prime and enamel,
or coat the metal with a waterproof grease.
CORROSION X, or equivalent, should also be
applied to stop corrosion and repel moisture
and contaminants.
Corrosion Limits
Area
Allowable
Thickness loss
Bottom skins
30%
Side Skins fwd of Step
30%
Side Skins aft of Step
20%
Top Deck
30%
Machining
0.015”
Struts
0.030”
NOTES:
1.
Maximum surface area for skin corrosion,
up to to the maximum depth, shall not
exceed one (1) square inch and must be
separated by at least 14 inches from any
other skin corrosion damage.
2.
For machined fittings, struts, and pylons,
corrosion limits are provided as maximum
pitting depths. Corroded surface area for
these limits shall not exceed 0.5 square
inches, and must be separated by at least 5
inches from any other corrosion damage
FIGURE 8-1: CORROSION LIMITS