Cleaning Methods For Non-Destructive Testing - Lycoming YO-233-B2A Maintenance Manual

YO-233-B2A Engine Maintenance Manual
TEO-540-A1A Engine Maintenance Manual
G. There must not be any cleaning agent residue on the metal surfaces. Any chemical that could
either corrode the metal or create hydrogen gas which can cause hydrogen embrittlement
during service.
H. Paint strippers are usually organic solvents like MEK or acetone or toluene, etc. and typically
will not cause any damage to metals. Except for chlorinated solvents (such as trichloroethane,
trichloroethylene, "perc"-degreaser, etc.), just about any other type of solvent can be used on
steel or aluminum parts. Chlorinated solvents can react with moisture and produce some
hydrochloric acid which could harm the metal.
12. Cleaning Method for Non-Destructive Testing
A. Remove all traces of:
• Paint
• Gasket materials
• Oil
• Grease
• Dirt
B. Use any of the following cleaning methods as long as it is not harmful to the component or its
intended function:
• Vapor degreasing
• Solvent degreasing
• Ultrasonic cleaning
• Chemical cleaning
• Aqueous-based cleaning
• Mechanical cleaning (such as grit-blasting)
NOTICE: Grit blasting without etching can be an acceptable cleaning method if it can be
demonstrated that a sufficiently fine abrasive (150 grit or finer) will not cause
peening and can be removed by a detergent or alkaline cleaner.
Etching of the area(s) to be examined is to be done prior to inspection when
evidence exists that previous cleaning, surface treatments, or service usage has
produced a surface condition that degrades the effectiveness of the penetrant
examination.
© 2021 Avco Corporation. All Rights Reserved
February 2021
• Corrosion
• Smeared metal
• Plating
• Chemical residues
05-30
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