(3)
Examine the fasteners and the area round the fastener holes to make sure they are cleaned free of any contamination.
NOTE: Stainless steel fasteners are usually located at four locations per panel, one at each corner.
(4)
Use aliphatic naphtha to clean the fasteners and area on the fairing panel around the fastener holes.
(5)
Remove any paint or primer covering the conductive surface of the panel in the are of the dimple washers.
(6)
Prepare the surface for the anti-static coating.
(a)
Apply anti-static coating over the exposed areas.
(b)
Install the fasteners (stainless steel bolts and dimple washers).
1) Install the stainless steel bolts and dimple washers in the same locations on the fairing panel, as they were when you removed the panel.
NOTE: If you install different hardware in these locations you can get an acceptable electrical bond.
(c) Measure the electrical bonding resistance between the conductive fasteners and the conductive surface of the fairing panel.
NOTE: You should make the resistance measurement before you paint the panel and the mounting hardware. If the fairing panel and bolts have been covered with paint, you may not get a correct measurement. In this case, use two sharp probes and make sure the probes contact the conductive surface of the panel and the structure. Then, measure the resistance.
1) Make sure the maximum resistance is not more than 300,000 ohms.
(7)
Touch up the finish.
(8)
Measure the resistance with aluminum foil strips.
(a)
Press two parallel metal strips of the same length L, separated by 0.1 of the length, firmly against the coating.
(b)
Measure the resistance with a multimeter.
(c)
Maximum resistance between the two strips is 10,000 ohms.
500
51-21-71 Page 702 BOEING PROPRIETARY - Copyright . - Unpublished Work - See title page for details. Feb 01/95
I. If resistance of conductive coating exceeds maximum allowable value per step H.
(1)
Sand conductive coating using 240 grit or finer abrasive paper.
(2)
Remove sanding residue by wiping with clean cheesecloth wet with aliphatic naphtha. Wipe dry with clean cheesecloth.
(3)
Reapply conductive coating per steps B thru G.
(4)
Recheck resistance per step H.
J. Immediately prior to applying any required overcoat, wipe surface with clean cheesecloth wet with aliphatic naphtha. Wipe dry with clean cheesecloth.
F85316
500 Cure Time
Feb 01/95 Figure 701 BOEING PROPRIETARY - Copyright . - Unpublished Work - See title page for details. 51-21-71 Page 703
ABRASION RESISTANT TEFLON FINISH - APPLICATION
1. General
A. This section describes the surface preparation required and application of a sprayable and brushable, abrasion, chemical and solvent resistant finish to chafing surfaces.
B. Apply the abrasion resistant Teflon coating over BMS 10-79 primers. Apply 5 to 10 mils (0.005 to 0.010 inches) dry film. Total dry film thickness of 20 mils (0.020 inch) maximum may be applied.
C. The sprayable material systems are to be used for spray application.
D. Use the brushable materials for those areas where spraying is not practical, and where dry to handle times of from 1 to 2 hours are required. Spray application is permitted where a 45-minute pot life can be tolerated.
E. Clean and proper equipment shall be used.
F. The spray-applied coatings shall be uniform, free of skins, lumps, gelled or coarse particles. Brush marks, sags, and runs on brush-applied surfaces are acceptable.
G. All spray painting of airplanes should be limited to areas having good general ventilation. All painting of small parts should be confined to a paint spray booth having adequate exhaust ventilation. Respirators should be worn when proper exhaust ventilation is not available.
WARNING: TEFLON FINISH CONTAINS TOXIC AND FLAMMABLE COMPONENTS. AVOID BREATHING VAPORS. DO NOT GET IN EYES, ON SKIN, OR ON CLOTHING. ALWAYS WASH HANDS BEFORE EATING OR SMOKING.
H. Material shall be properly mixed.
I. Material whose pot life has been exceeded shall be scrapped and not used.
J. Material whose shelf life (1 year) has expired shall be rejected. Shelf life of the Teflon coating is 1 year from date of manufacture.
K. Stripper (Ref 51-21-11, Paint Stripping)
501
May 1/75 BOEING PROPRIETARY - Copyright . - Unpublished Work - See title page for details. 51-21-81 Page 701
中国航空网 www.aero.cn
航空翻译 www.aviation.cn
本文链接地址：737 AMM 飞机维护手册 结构 STRUCTURES(19)
