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Ted Mooney, P.E. RET
Pine Beach, NJ
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for Metal Finishing since 1989
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Chemfilm paint adhesion
Which finish has better paint adhesion properties and why, MIL-C-5541 class 1 or 3A?
Matt Kubiakengineer - Boulder, Colorado
March 30, 2009
April 7, 2009
Matt
Refer to section 6.12 of MIL-DTL-5541
[on DLA] F. "Excessively thick coatings may result in paint adhesion problems...".It is reasonable to expect to see this cause only with Class 1A coatings.
Refer to section 3.6.2 of MIL-DTL-5541F for information on the adhesion requirements.
Both classes can be successfully painted.
- Colorado Springs Colorado
Hi Matt,
Per MIL-DTL-5541
[on DLA] (formerly MIL-C-5541) both Class 3 and Class 1A will improve paint adhesion and it doesn't much specify which one does better (except of course for the one warning that in improperly applied - too thick - coating may have a negative effect). However, it is worth noting that Class 1A is the default (effectively), and class 3 is specified in those cases where low electrical resistance is required. If that isn't a concern of yours (can't see how it can be given that you are painting it) Class 1A will give you better corrosion resistance under the paint.
Good luck!
Compton, California, USA
May 26, 2009
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