menards has a rhino lining like stuff in a quart(maybe a gallon) can for around 80 bucks last i saw. sometimes they have a rebate with it. bet it gets cheaper around this time of year. i saw at the indiana state fair last year a 12 foot jon on rhino's display that they did the whole boat inside and out. also if the seams are splitting i dont think lining it would do anything for the seams other than seal them for a while. i put everything on mine until somebody gave me a can of roofing tar. hasn't leaked yet. if it gets too bad i'll take and recycle it and buy another beater.