Zinc Phosphate Primers

[GPV]

Does anyone know how effective zinc phosphate is for preventing aluminium corrosion? I'm trying to find some hard data but there isn't much out there! Not sure it's as effective as it is for steel.

Consequently, any thoughts on whether a 2 part zinc phosphate based epoxy primer with "good" adhesion would be preferable to a zinc-free 2 part epoxy primer with "excellent" adhesion? This is for internal surfaces of course.

If the zinc phosphate is of marginal benefit I would prefer the one least likely to scratch or chip aka option B.

Any advice would be appreciated!

Greg

[BillL]

Sorry you will have to search, but I posted some links to test reports on primers does by the USA DoD. There was a get from Georgia that added a link to a more recent one too. Sorry you will have to search, I can not remember them, but just know they are posted here.

[GPV]

Thanks Bill, I'll dig the post up!

[Sue]

Heard of zinc cromate, not phosphate?

[GPV]

Originally Posted by Sue

Heard of zinc cromate, not phosphate?

https://www.aircraftspruce.com/catalog/cspages/zinc.php

[rmartingt]

Originally Posted by Sue

Heard of zinc cromate, not phosphate?

There's a big push to get rid of chromates due to health and environmental concerns (hexavalent chromium is a nasty carcinogen).