Soft deck ,driver seat
 

bought 89 v20 replaceing driving seat discovered old holes were not filled and floor is soft.
Any suggestions on how to fix.it is only soft about a 1 foot by 1foot area

tap around the area with a screwdriver handle or rubber mallet to determine the extent of the damage. cut out bad area, drop in a piece of new deck, glass and fair, then try to match gelcoat or paint.

i also installed some small deck inspection plates so when i reinstalled the seats, i could through bolt with backing plates.


look in the links section for fiberglass repair manual by west epoxy.
take pics and post your project

cut a rectangle out. use a circular saw with a fine blade and only go in 1/2" . try to chisel out the wood & top skin, leaving the bottom glass skin intact. sand it clean. If you can save the whole top skin, reuse it later.

Replace with exterior grade AC or BC douglas fir ply. Coat it with boaters resin ( with hardener). Let harden. In about an hour, squish it in place with some adhesive filler/resin (Bondo in a pinch).
Glass over the top and fair it using filler/resin (Bondo). sand it flush.
Coat with a thin "painted on" layer of resin( you could use epoxy here).
Paint to match as close as possible.


Now you gotta paint the whole deck....

Thanks for help advise guys .im going to do it in the fall

Would love to see pics of the job from start to finish so it can help others ( and me) in the future , let us know how hard the job is I'm always scared about opening up the floor deck and I don't know why,

I was gonna say wait till the season is over so you can enjoy your boat. Projects like that aren't technically hard, but the damage usually doesn't get better once you tear into them.