: One thing I have been wondering about is the use of polypropylene. Has anyone
: tried it as abrasion protection? I would think it would do very well.

I did a Ch16 s&g with 4oz polyethelene over 4oz s-glass. The poly cloth synthetics use up a LOT of resin for the amount of abrasion resistance or panel stiffness they contribute compared to comparable amounts of glass or s-glass using similar amounts of resin. In other words it'll take about the same amount
resin to wet out and fill 4oz poly cloth as it'll take to wet out and fill two layers of 4oz e/s-glass. I'm pretty sure that two layers of 4oz s-glass will hold up better than one layer of poly cloth where the cloth is needed for panel strength. For abrasion resisance in high wear areas like the stern you have to have a thick layer of something,,,one or two layers of 4oz poly cloth isn't thick enough to be worth the effort compared to other methods.