Maybe I don't have to scrap the boat after all!!
6-136. EXAMPLES OF REMOVING
CORROSION FROM ALUMINUM AND
ALUMINUM ALLOYS.
a. Positively identify the metal as aluminum.
b. Clean the area to be reworked. Strip
paint if required.
c. Determine extent of corrosion damage.
d. Remove light to moderate corrosion
with one of the following.
(1) Non-Powered Corrosion Removal.
(a) The removal of corrosion products
by hand can be accomplished by use of
aluminum grit and silicon carbide abrasive,
such as non-woven, non-metallic, abrasive mat
(Spec. MIL-A-9962), abrasive cloth, and paper.
Aluminum wool, fiber bristle brushes, and
pumice powder are also acceptable methods.
(b) Stainless steel brush (Spec.
H-B-178, type III, class 2) may be used as long
as the bristles do not exceed 0.010 inch in diameter.
After use of this brush the surface
should be polished with 60 grit aluminum oxide
abrasive paper, then with 400 grit aluminum
oxide paper. Care should be exercised in
any cleaning process to avoid breaking the
protective film.
(b) When using abrasive blasting on
aluminum alloys, do not allow the blast stream
to dwell on the same spot longer than
15 seconds. Longer dwell times will cause excessive
metal removal. Intergranular exfoliation
corrosion is not to be removed by abrasive
blasting; however, blasting may be used with
powered corrosion removal to determine
whether all exfoliation corrosion has been removed.