Ask the Expert Question-and-Answer Archive

by Ron Joseph

October, 2007

MIL-P-23377 Epoxy Primer

Q: Is Epoxy Primer MIL-P-23377 compatible with Top White Coat  Aerodur Finish C 21/100 UVR-77284 which is a High Gloss very durable polyurethane finish or do you have to use a special wash primer?

A: MIL-P-23377 is designed for use as a primer under a polyurethane.  To be sure that you get the compatibility you require, you might consider purchasing your MIL-P-23377 from Akzo Nobel, who are also the manufacturers of Aerodur. 

You absolutely positively do not want to apply a wash primer over the epoxy primer. That could be disastrous! Wash primers are only used for direct to metal application, and they must never be applied over metals that have been pretreated with a conversion coating, such as Alodine, ChemFilm, Bonderite, etc.

Regards,

Ron Joseph