Roof question 69

[bobfist]

Hi!
Wonder what this is...
Did they use some kind of special primer under vinyl roof, it dosent act like rust but looks like it

[vancamp]

it looks like rust to me

[lexxman]

I have the same thing on my roof and yes its rust. And it is hard to sand,you can blaster it or use a rust remover.I was just out in the garage getting reed of it.

[BlueSS454]

That's rust, my 69 had the same thing.  I had mine media blasted.  If you want to use a lot of elbow grease, you can use naval jelly and steel wool but it will take forever to do.