SERVICE MANUAL & I.C.A. FOR THE 7000 AMPHIBIOUS FLOATS
Revision G Page 78 of 102 P/N 1004646 Doc. No. W7001-24-01
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%
Machinings
0.015”
Struts
0.030”
NOTES:
1.
Maximum surface area for skin corrosion, 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
9-1:
CORROSION
LIMITS
