Clean the area where the crack is located with mineral spirits and a rag. The mineral spirits is used to remove any debris and to prepare the area for the repair.
Cut the fabric from the repair kit into three or four pieces slightly larger than the area that is cracked. The fabric is cut with a standard pair of scissors.
Mix the epoxy and the hardening agent from the kit according to the directions on the kit. Mix the ingredients in a plastic container.
Brush the epoxy mixture onto the surface where the crack is located using a 2-inch paint brush.
Lay a piece of the fabric over the area and smooth it out. Brush more epoxy mixture over the fabric and lay another piece of fabric over it. Repeat this one to two more times. Brush a final coat of the epoxy mixture over the top of the last piece of fabric and let it dry for 24 hours.
Sand off the rough spots using an emery cloth and paint the surface with a fiberglass paint.