Hey, the white stuff is just the product itself, after it dried without interacting with the rust. I've been reading some history posts, and apparently this is the kind of thing that Ospho is supposed to do. I'm thinking of trying that next, since I have a bottle of it. But I've sort of been blaming the Ospho for the advanced rust on my truck in the first place. I had bought the stuff a few years back to use on an old Mustang that we didn't keep very long. Then, three years ago, I hit the second deer going to work in my truck. I needed to get it back together over the weekend, and came up with junkyard parts just as the junkyard was closing on Sat. I realized the radiator support had a rusted through place and figured I had to use it because of time, but pretty much coated the piece in the Ospho. I didn't paint over it or anything. I didn't put a grill back in it since I bought a new aftermarket rad. support and have been waiting for a chance to tear it back apart. The radiator support has been looking rustier every time I looked at it ever since. I think maybe you have to paint over the Ospho, or neutralize it, or the acid will promote further rust. I've gone ahead and primered the frame section and battery tray, since they are both thick steel in the first place. Waiting for warmer weather to paint it so I can put it back together. Really want to know how to do this for the steel rims on a bike project, though.