I have a patio table that I want to mosaic. The top is 42" round and I believe it is fiberglass. The top is in real good condition, but not completely smooth, it does have some "graining" in it. Can I mosaic directly onto the top or should I add to or replace it? Also, there is a hole in the center (for an umbrella) that I will need to cover somehow.

This is a big project for me and I don't want it to last just a few years!!