I got the outer stringers sanded down using an orbital sander to get most of it out, then followed with a belt sander. I used 1.5 oz csm over the outer stringer area to even out the surface. I will use foam core on the outer stringers. which I still need to cut to shape. The first layer of csm was used to cover the stringers that I have so far. I plan on pulling a layer of travira on the top only which is would allow the glass to hold screws. I final layer will be 3610 which is an overkill, but is better than an underkill.