Zamac oxidation

[casinogarage]

This thermostat housing is new, freshly painted and after just some monthes stocking this oxidation appear !

Do you now a product able to stop this damage ?

[bwaminispeed]

Probably wasn't cleaned well enough before painting..........

Best procedure is blast it, if possibly, a good coat of epoxy primer, and, then 2-3 good coats of paint to seal it against moisture intrusion...

[Spider]

As above, it needs blasting and then a proper etch-prime before painting, however, even then, don't expect miricles.

This is actually one item, being alloy, that Powercoats exceptionally well.

[casinogarage]

OK, many thanks, the lack of primer appear to be the explanation. I'll follow your advice ! I think use a new item will be better.