If you need sturdiness, drop a couple extra bucks and purchase fiberglass cloth. Once you've put on an initial layer of resin to the inside and out, apply the fiberglass to the inside and resin it . If you do this right, your armor will survive mosh pits. I wouldn't recommend diving into them, but you'd be amazed how much of that is out of courtesy to others rather than to spare your armor.
"The important thing is no one was hurt... No one who counts."