INTRODUCTION: This document will give the procedures to be carried out for detection of surface crack on aircraft aerofoil suspected to be cracked using the color contrast Dye Penetrant technique.
Inspection should be carried with the field kit consist of 1) Penetrant 2) Cleaner or remover 3) Developer-to eccentricity any indications. All three items are readily available in aerosol forms.
1.Make sure that proper hand gloves and face mask is readily available. 2.Clean the surface of a part and remove the surface paint using paint strip removers thoroughly followed with degreasing the part in accordance with the given instructions. 3.Do not use any abrasive methods .If the surface is slightly spoiled, clean it by aerosol application of penetrant remover.
2. Application of Penetrant:
1.Make sure that surrounding temperature is between 10-30 degree. If the temperature is lower, then extra care should be taken for precleaning and extra time should be given for drying of the penetrant. 2.Before applying the penetrant, make sure that the penetrant is correct for the purpose required and use aerosol can to spray the penetrant on to the surface of the item. 3.Maintain a distance of 8-12 inches between the aerosol can and the testing surface to prevent over spraying. 4.The penetrant gets pulled into the surface defects by capillary action. 5.Allow the penetrate to soak into any flaws for 30-40 minutes. Make sure that the dye has penetrated to the narrowest crack. Generally a smaller flaw takes a longer penetrate time. 3. Excess Penetrant Removal:
1.Use the solvent remover and lint free cloth for removing the excess penetrant form the surface. 2.Make sure that solvent is not sprayed directly on to the test surface as this may remove the penetrant from the flaws. 3.This process must be done very carefully to ensure...