NOTE:____After 5 hours, the surfacer becomes very hard. You must make the surface smooth before 5 hours.
(g)
Use a clean cheesecloth that is moist with naptha to remove all remaining particles.
NOTE: If microscopic or small holes show on the surfacer,
____ apply Magna 28-C-1 again after you rubbed and cleaned the surface. Immediately apply the subsequent layers as soon as possible.
S 107-015
(2) Do these steps for surfaces with no paint and for surfaces without surface porosity.
(a)
Use Scotchbrite sheets and clean water to make the surface rough.
(b)
Use a cheesecloth that is moist with water to clean the surface. Clean the surface again to remove all remaining particles.
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A
747-400 MAINTENANCE MANUAL
CORROSION REMOVAL AND CONTROL - CLEANING/PAINTING
_________________________________________________
1. General_______
A. This procedure contains one task. The task is to remove corrosion and apply solutions to control the corrosion.
B. Carefully examine all structural parts where corrosion can occur. Replace these parts or repair them if it is possible. Apply the protective finish on the part or surface. If it is not possible to remove the part, use the applicable procedure to control and remove corrosion.
C. Corrosion removal and control procedures are applicable to all areas. Use these procedures only for small quantities of corrosion. To remove large quantities of corrosion, refer to the Structural Repair Manual.
D. Make sure that all areas that are prepared for corrosion inhibiting compounds are clean. Remove oil, grease, dirt, and paint from the surface or the part.
E. Make sure you remove all corrosion material from the surfaces or parts. Failure to remove all corrosion material can permit corrosion to start again. For limits of corrosion removal, refer to the Structural Repair Manual.
F. Use acid brighteners for aluminum. Acid brighteners are strong in acid concentration and can cause damage to metal surfaces. Phosphoric acid-type corrosion removers are weaker in acid concentration but can cause damage to metal surfaces.
G. If you cannot immediately remove corrosion from an area, prepare the area with BMS 3-23 (AMM 51-24-13/701). The BMS 3-23 is used to stop corrosion.
TASK 51-21-03-107-001
2. Remove the Corrosion____________________
A. Equipment
(1) Cleaning brushes, nylon and wire; Commercially
available
B. Consumable Materials
(1) Acid brighteners for aluminum
(a) B00001 Kelite L-20
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747-400 MAINTENANCE MANUAL
(b) B00002 Metal Glo No. 2
(2)
B00137 Abrasive paper, aluminum oxide, 220 and 400 grit
(3)
G00133 Tape - Masking, No. 221, 3M Company
(4)
B00312 Aluminum Wool
(5)
B00446 Stainless Steel Wool
(6)
C00064 Coating - Surface Treatment - MIL-C-5541, Type II, Grade C, Class 1 for Aluminum or Aluminum Alloys (Alodine Coating) Alodine 1000 Clear, Alodine 1200
(7)
G00034 Cheesecloth - New, Clean, Dry, Lint Free
(8)
G02223 Paper - pH neutral
(9)
E00079 Stripper, Inorganic - Chromic Acid
(10)
G00009 Compound - Corrosion Inhibiting BMS 3-23
(11)
B00047 Corrosion Remover - 0-A-88 Nitric Acid
(12)
Corrosion Remover - Phosphoric Acid Type (for aluminum)
