TM 55-1520-240-23-4
5-20
REPAIR PITCH BEARING OIL TANK (AVIM)
(Continued)
5-20
4.
Fluorescent inspect damage that exceeded 0.010
inch in depth before rework (TM 1-1500-335-23).
5.
Finish reworked areas of magnesium pitch
bearing oil tank (4) as follows:
Chromic acid (E114) is extremely
toxic. It can irritate skin and cause
burns. Avoid inhaling. Use only with
adequate ventilation. Avoid contact
with skin, eyes, or clothing. In case
of contact, immediately flush skin
or eyes with water for at least 15
minutes. Get medical attention for
eyes.
NOTE
Do not wash surface with hot water.
a.
Prepare a type VI solution of chromic acid
(E114).
b.
Brush solution (E114) on blended areas.
Wear gloves (E184.1).
c.
Keep surface wet for 1 to 3 minutes then
wash surface with cold water and dry with
hot air.
6.
Finish reworked areas of aluminum pitch bearing
oil tank (4) as follows:
Alodine powder (E65) is an oxidizer.
Discard cloths which contain this
material in a separate container. If
discarded with cloths contaminated
with acetone, MEK or other organic
solvents, combustion can result. In
case of contact, immediately flush
skin or eyes with water for at least
15 minutes. Get medical attention
for eyes.
a.
Mix 3 ounces of alodine powder (E65) with
1/2 ounce of concentrated nitric acid (E22).
Add mixture to 1 gallon of water.
b.
Swab alodine solution on area. Swab for 2
to 5 minutes. Wear gloves (E184.1). Use
gauze sponges (E184).
c.
Rinse surface with cold water and let air dry.
7.
Apply one coat of epoxy primer (E292.1). Wear
gloves (E184.1). Let air dry for 1 hour.
8.
Apply two more coats of epoxy primer (E292.1).
Wear gloves (E184.1). Allow 1 hour between
coats.
9.
Apply two coats of black polyurethane paint
(E285.1) per Task 2-350.1. Wear gloves
(E184.1). Allow 1 hour between coats.
10.
Remove cap/plugs and masking tape (E388)
from pitch bearing oil tank (4).
FOLLOW-ON MAINTENANCE:
None
END OF TASK
5-102
