I had a 6 inch crack on the rear section of my camper. I drilled a small hole at the end of the crack to stop migration. I use a Dremel with a round bit and made a fillet the length of the crack. I used JB Weld Plastic Bonder to repair the crack. I've only found it in two colors which is black and tan. After curing, I lightly sanded it smooth and repainted the area. Worked good for me. Pictures are pre painting. Good luck.