Osphos Prep

[Simbad68]

I've used Osphos in the past on steel flanges and then painted with enamel. What steps need to be taken to apply a sealer or primer over Osphos? Does it need to be sanded and prepped before the primer is applied? What primers work best with Osphos, Epoxy or self etching? And does the oshos need to be removed before welding, or can it be welded through?
Thanks-Sims