Ask the Expert Question-and-Answer Archive

by Ron Joseph

January, 2005

Surface Preparation for Painting a Small Plane

Q. I have a small plane with surface corrosion under the paint. I need to know the proper preparation before using chromate and what type chromate should be used?

A. Ideally the surface prep comprises a thorough wash down of the aircraft followed by a wash down with a chromate conversion coating, such as Alodine, Chemfilm or equivalent. If you absolutely can't do that, then you must use a wash primer; however, that has its limitations and application problems.

The primer should be a chromate primer complying with MIL-P-23377 or equivalent.

I suggest that you visit the paint shop at the Naval Aviation Depot to see how they do this work. You will then be able to determine what processes you are capable of doing yourself. By the way, at which depot are you?

When preparing any surface for the application of paints or coatings, be certain to take precautions to protect against breathing in any air borne dust particles or debris that may be created by the prep work.

Please be aware that paints, coatings and solvents are chemicals and therefore you should always pay attention to proper handling procedures and be prepared to wear protective clothing, such as respirators, gloves, coveralls, etc. For further information on the health and safety requirements for the coatings and solvents you wish to use we strongly advised you to contact your local coating supplier. If possible, go the extra step and look for this information on the website of the product vendor.

Best wishes,

Ron Joseph