Treatments for painting galvanised chassis

Hi guys, just a quick update, I now have rebuild the front axel and half the rear axel. Need the source a rear diff as old one has damaged pinion any advice on that.

Main question is best products for treating new galvanised chassis ready for painting.
Any advice will be much welcomed.
Cheers

You can get galv primer as a solution, i belive it is phosphoric acid based, it etches the galv,
There is also rustoleum special paint primer which says suitable for galv on the label which i used when i painted my galv chassis, tbh it didnt seem a good product as it dried quickly and seemed 'chalky' but time will tell, i also put a couple of coats of zinc rich primer on before the top coats,
Atb and good luck.