I have a concrete dock with about 50 places where rust is coming up and spreading on the surface. One contractor says to chisel out old, repair, patch, then cover with Spraycrete. Another says to put down tar paper to seal and pour a 4" cap. The third says epoxy will seal old concrete and then pavers will cover. What is the best permanant solution? The pavers sound a lot easier and I could go with the 1/2" thickness. The 4" cap adds alot of weight and height to the dock.