I remember seeing an an alternative to Kevlar skid pads for a Royalex Canoe. Is the S-glass a better option?
Skid plates, an evolution
Just about anything is better
if you are talking about Kevlar felt.
Felts are materials made from very short, compressed fibers. The fibers may be very strong, but since no fibers run the length of the plate, or for any real distance at all, the entire structure lacks integrity. The felt materials also tend to soak up too much resin, resulting in a high resin/fabric ratio, which makes a plate made from felt both heavy and brittle. They also tend to be much thicker than they need to be, which creates more drag.
The result is that significant impacts to Kevlar felt skid plates tend to crack them and break out chunks of material. Aramids like Kevlar are also not the best choice of fabric for exterior use if it is subjected to much abrasion. Aramids tend to "fuzz up" when naturally abraded or sanded, which again results in more drag, and makes it difficult to feather the edges of a skid plate.
I feel that the best materials for abrasion plates is either Dynel or S fiberglass, although E fiberglass either woven or tape, is certainly a possibility. I would choose a plain weave fabric. Plain weave Dynel is available in 5 oz/sq yd weight. Plain weave fiberglass cloth is widely available in either 4 oz/sq yd or 6 oz/sq yd weight.
Dynel soaks up more resin so one layer of 5 oz fabric is usually enough. If you use fiberglass you may choose to use multiple layers, especially if you choose 4 oz fabric. The best resin to use on Royalex is West System's G Flex epoxy.
I recently applied Kevlar Felt skid pads to a Royalex boat using the G-Flex epoxy. I first painted a layer of epoxy to the hull and and then layed the pad over the top and put more epoxy on. The pads did not soak up the epoxy very well. The G-flex seemed thick. I immediately ran to the front garage and mixed up a batch of 105/206 and that soaked in well. As others have stated, very ugly thick pads.
I’ve been using Bodyguard tape
clear or colors avail. http://www.cabelas.com/product/Trimbrite-Bodyguard-Paint-Protection-Film/746765.uts
It is not as strong or abrasion resistant as those mentioned earlier but for the price, weight, and ease of use it works fine on my sea kayak. I’ve had it on for about five years with few problems. One note if you get rock dings in it trim them down with a razor blade, I seen one sharp edge draw blood when picking up the boat.