WARNING: USE CORRECT PERSONAL PROTECTION. COMPRESSED AIR WILL CAUSE LOOSE PARTICLES THAT CAN GET IN YOUR EYES. COMPRESSED AIRFLOW CAN CAUSE CUTS, DO NOT POINT IT AT YOUR SKIN.
(7)
Pressure air-dry (20 psig (137,895 kPa) maximum) to remove excess water from part.
(8)
Dry parts in oven at 250F (121C) for two hours.
Cleaning
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H. Method No. 203H: Cleaning Corroded Magnesium
CAUTION: CORROSION MAY BE CAUSE FOR REJECTION OR REPAIR OF A PART. REFER TO INSPECTION (SECTION III) AND/OR REPAIR (SECTION IV) WHENEVER CORROSION APPEARS TO BE BEYOND SURFACE FINISH.
Clean corroded magnesium parts as follows:
WARNING: SOLVENT VAPORS ARE TOXIC AND FLAMMABLE. DO NOT INHALE VAPORS. OBSERVE FIRE PRECAUTIONS.
(1)
Clean surface with solvent (Federal Specification P-D-680, Type I) (SECTION VII) to remove oil and grease contamination.
WARNING: USE CORRECT PERSONAL PROTECTION. ALKALINE CLEANING SOLUTIONS ARE HAZARDOUS. AVOID INHALING FUMES OR MIST. AVOID CONTACT WITH SKIN. AFTER USE, WASH HANDS AND FACE THOROUGHLY.
(2)
Immerse parts in alkaline cleaner solution (Method No. 202A) for 10 to 15 minutes.
(3)
Scrub surfaces with a stiff fiber bristled brush to remove any loose contaminants.
NOTE: If old gaskets or sealing compounds are stuck to flange areas, carefully lift softened materials with a knife blade and scrape surface clean.
(4)
Rinse parts in water at 80 to 110F (27 to 43C).
WARNING: USE CORRECT PERSONAL PROTECTION. COMPRESSED AIR WILL CAUSE LOOSE PARTICLES THAT CAN GET IN YOUR EYES. COMPRESSED AIRFLOW CAN CAUSE CUTS, DO NOT POINT IT AT YOUR SKIN.
CAUTION: ALL TRACES OF MOISTURE SHALL BE REMOVED IMMEDIATELY TO PREVENT CORROSION.
(5)
Pressure air-dry (20 psig (137,895 kPa) maximum) to remove excess water from part.
(6)
Place in an oven at 250F (121C) for two hours to complete drying.
Cleaning
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WARNING: USE CORRECT PERSONAL PROTECTION. COMPRESSED AIR WILL CAUSE LOOSE PARTICLES THAT CAN GET IN YOUR EYES. COMPRESSED AIRFLOW CAN CAUSE CUTS, DO NOT POINT IT AT YOUR SKIN.
CAUTION: REGULATE AIR PRESSURE TO KEEP EROSION OF BASE METAL TO A MINIMUM. KEEP NOZZLE IN MOTION TO PREVENT BLAST FROM DWELLING ON ONE SPOT.
(7) Glass bead peen corroded areas to remove corrosion.
NOTE: Glass bead peening or abrasive blasting shall not be used until fluorescent penetrant (SECTION III) inspection has been performed.
If glass bead peening equipment is not available, abrasive blasting at 15 to 30 psig (103,42 to 206,8 kPa) may be used to remove corrosion. Mask any surface that could be damaged by abrasive blasting.
If paint is loose or blistered following cleaning, refer to Repair (SECTION IV) for treating and repainting.
CAUTION: ALL TRACES OF MOISTURE SHALL BE REMOVED IMMEDIATELY TO PREVENT CORROSION.
(8)
Rinse surface free of glass beads (Screen No. 100-230 (130 Grit) Class IV, Size AF or AG) (SECTION VII).
(9)
Dry part in oven at 250F (121C) for two hours or proceed immediately with the Step (10).
CAUTION: WHEN PREPARING MAGNESIUM TOUCH-UP SOLUTION USE EXTREME CAUTION TO PREVENT CONTACT WITH SKIN. IF POWDER OR MIXED SOLUTION COMES IN CONTACT WITH SKIN, FLUSH OFF IMMEDIATELY WITH WATER. DO NOT INHALE DUST FROM POWDERS OR VAPORS FROM THE SOLUTION.
(10)
Immerse parts in magnesium touch-up solution (Method No. 202F) for 15 to 45 seconds.
CAUTION: ALL TRACES OF MOISTURE SHALL BE REMOVED IMMEDIATELY TO PREVENT CORROSION.
(11)
Rinse in clean tap water at 50 to 90F (10 to 32C).
WARNING: USE CORRECT PERSONAL PROTECTION. COMPRESSED AIR WILL CAUSE LOOSE PARTICLES THAT CAN GET IN YOUR EYES. COMPRESSED AIRFLOW CAN CAUSE CUTS, DO NOT POINT IT AT YOUR SKIN. 中国航空网 www.aero.cn 航空翻译 www.aviation.cn 本文链接地址：标准施工手册 STANDARD PRACTICES MANUAL 20-00-02/70-00-01(26)
