touch up with MIL DTL 5541 class 1A

[kevlar49]

Is there any reason why we couldn't touch up scratches on a MIL DTL 5541 Class 3 with Class 1A? Either class 3 or 1A properties will suffice. I just want to know if there will be some incompatibility issues that could deteriorate the existing class 3 coating.

 

[tbuelna]

I'm assuming you understand that cl.3 chem film is intended for use where low electrical resistance is required. If you touch-up damaged areas of a cl.3 chem film using a cl.1A process the repaired areas will not have the same electrical resistance properties as the basis coating, and some might consider that a "deterioration" of the basis coating. MIL-DTL-5541F section 6.5 covers interchangeability issues, and section 6.17 covers limits on size of the area that may be touched-up without approval.

You might also take a look at MIL-DTL-81706 which covers materials/processes used for chem film coatings.