[Hangen by a string]

Hi everyone, apparently i bought my fenders a bit too late. the dock i tied up to put 2 nice gouges in my starboard hull and dinged up my rub rail a bit. Doubt i can repair the rail but can someone advise me about the hull please.

it cut a gouge about a inch long and 1/8" deep. the portion cut out is still attached to the hull so i simply need to push it back in place and reseal . just not sure about the heat source needed.

thanks , Roy