White rust on steel door

I have a problem with steel door's that have been exposed to rain at some point during shipping, and being of the wipe coat galvanize material have developed a white rust on the surface ,after sanding is there any product to brush on to stop it returning after we have painted? looking forward to your reply

Dear sir,
you don't have to worry if you have painted your door already, as white rust will not affect the painted steel.

best regards
S.R. Ameen

Visit your local auto shop and purchase some 2 pack wash primer. Mix as directed and either spray or even brush a very thin coat over the galv. Allow to air-dry and apply top-coat ASAP. You could leave it a few days but no longer.
The primer will improve adhesion and weathering properties. If you can buy some extra recommended thinner and some of the catalyst (Phosphoric acid solution) mix these say 80/20 ratio and wash the substrate down with this (prior to applying wash primer). This will neutralize the ZnO (white rust).

adv.
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