gel coat problem

[megapower]

hello new boat owner here after purchasing the 25 ft bayliner i found a scrape at the bottom of the hull on the center beam. that goes from bow to stern .where the gel coat is gone and the fiberglass is showing. now the scrape is about 1/2 " to 3/4" wide and about 6" long . After reading all the gel coat repairs most talk about scratches and or major repairs where fiber is required. so in my situation oh the fiber not damaged just the gel coat is gone
what do i do ?
do i fill with bondo as was described on u tube or is there another way. also the best way to take off the bottom paint befor i start to prep area for repair . seeing that the paint is powdery .your hands turn blue when you touch it (normal?)
looking for help
thanks

[Griff]

Sounds like it got beached a lot. You could prep the area and fill with gel coat paste. Then just go over it with bottom paint again.
You could probably just go over the damaged area with a thick coat of bottom paint and call it good too.

[megapower]

thanks giff
but to get started the removale of the bottom paint .do i sand it off or do i use acetone to wipe it off seeeing it is so powdery . touching it comes off on to the hand . is this normal?. when i purchased the boat there ws no damage there so i thought . after a long run on the water i found it when it was slung out . so i suspect it was patched and the patch fell out. thanks again

[Elite Marine]

Thats typical of bottom paint. Sand it off. Fill the gap with gel and then bottom paint. It will be fine. Make sure its dry though.

[megapower]

thanks elite marine