Eddie,

I had the same problem when I removed the old vinyl stripes. The part that was under the plastic has been protected from UV and wind/water erosion, so you usually need to sand the hulls to really reduce the effect. Try cleaning well with Oxalic acid first to see how much difference there really is.

What color are your hulls?

[img]http://www.thebeachcats.com/albums2/album59/MVC_007F.sized.jpg" border="4[/img]