Zinc coating per QQ-Z-325 future.

[israelkk]

I prefer to use QQ-Z-325C to specify thin coatings Type II Class 3 because it specify 36 hours of salt spray compared to 12 or less according to ASTM B633.

Although QQ-C-325 is obsolete many plating houses and companies such as Moog continue to use it.

I have a debate with QA and they use the "obsolete" literally and doesn't accept QQ-Z-325C. They fear that in the future it will not be possible to find the chemicals and plating houses to plate to this spec.

I will appreciate any experience, knowledege, insight, etc.

 

[mcgyvr]

Type II in ASTM B633 is 96 hours minimum.
I don't have access to QQ-C-325. Is type II in QQ-C-325 type III in B633? (colorless chromate). If your calling out a colored chromate coating then B633 is 96 hours.

 

[israelkk]

Sorry for a typo error, it should be Type III class 3 (5 micron minimum thickness). ASTM has an equivalent Type and Class for 5 micron minimum thickness but they guarantee less than 12 hours salt spray test compared to 36 hours in QQ-Z-325C.