I really question if it is in fact zinc chromate
Yes, that much I can be sure of. It is that rattle can stuff from West Marine that says ZINC CHROMATE in huge letters across the can. It bonds like superglue to the aluminum but I can't get paint to stick to it???
I was looking at that interlux system. I was hoping to not have to go that direction as I only have a few small things to paint and I would have to pick up nearly 3 quarts of material between all three steps.
BTW, Are you able to brush on the Primewash?