I didnt even think of that as an option. So the inside is coated with fiberglass and then epoxy paint? That ill save me hundreds and seems easier. Even tho its a longer process i do body work and have experience in carpentry so its within my grasp.
if you do it right ply can be very affordable. instead of a liner look into plastic sheeting cut to fit and sealed at the seems. Cheaper, effective, can be bought in black