Floor repair advice

[aby n]

I recently acquired a 1982 350v ranger bass boat that has floor rot under the drivers seat.

I haven’t cut it out yet, as I am trying to educate myself prior to making any cuts & I have some questions.

1. What board should I use? I measured 3/8 thick.
2. What should I treat the board with prior to use?
3. There is a gap between the floor board & stringer, when putting the new board on, should I apply glue to the spine of the stringer, fasten it down with screws or leave the gap? Pic included of current board.
4. I believe there is some rot that goes under the fiberglass of the boat, should I re-fill this area with strips of wood & secure it in place with some structural putty? My hope / thinking is to produce a nice square edge to drop my floor into place via a template. I will probably have to do 2 pieces of floor at the very least.
5. Which glass, resin do you recommend for doing this?

I’ve included 2 pics I found online for reference that look similar to my boat & the repair required.

I have yet to make a cut into my boat.

Thank you for any advice, aby ✌️

370v 1981_3.JPG370v 1981_2.JPG370v 1981_1.JPG350v_4b.jpg350v_3b.jpg350v_1.jpg

[Scott S.]

1/2" marine plywood will work. I replaced a floor in a boat that had a similar layout. I transformed the center section into more storage. I was ablble to get 9 plano tackle boxes in the hole, with lid. I used to build a few daycruisers and we always had the center section for ski locker, or roap storage. you would have to put a sub floor in the keel to let any water that gets in, it will keeep stuff dry if you go that route.

[mactlman]

if i was that far into it, I would revise the floor plan with a starboard and center box added to the deck

[aby n]

Yeah, my plan is to add a deck extension with storage after the floor is sorted out.

[JohnN]

I’d encourage you to get to the bottom of the foam to see if there is any water sitting there. If you had floor rot, there’s a good chance the foam is water logged but you won’t know it unless you take some cores out to see what’s down there.

[cooper.bohner]

I’d encourage you to get to the bottom of the foam to see if there is any water sitting there. If you had floor rot, there’s a good chance the foam is water logged but you won’t know it unless you take some cores out to see what’s down there.

+1 odds are if water got through the floor enough for it to rot it did not stop there.

[MikeF]

Take a piece of conduit or a tube of some kind and bore some holes to the bottom and see if the bottom of the cores are wet

Wait a few days and see if any water pools in the holes.

No water and you are good to go with the floor repair.

Good Luck

[aby n]

Thanks for all your replies.

The boat has been sitting in a garage for the last 5 years or so.

Do a core sample is a good idea, my guess is to do it in the area that had the most rot?

Also, is "marine grade plywood" good to use as is, or does it need to be treated before using/applying glass to the top / carpet side, to marry it to the existing wood?

[cooper.bohner]

So you can glass right onto marine grade plywood, and for the carpet side you don't want to carpet right onto bare plywood because it will trap moister and is a recipe for rot. Instead either coat in epoxy or fiberglass and then carpet over that and it will last much longer.

[aby n]

Foam is fine! Old, but dry.

Is there an epoxy resin that may set-up in colder weather than another?

How many layers of fiberglass should i apply on top of the wood?

[cooper.bohner]

Ive been using west systems 105 and 205 hardener and its good to up to 35 degrees

[Jeepguy]

PM me a phone number and I can text you a bunch of pics. I restored a 390 that was super trashed. Took out over 600 pounds of wet foam.

[aby n]

so i went to a local shop & they have 3/4 oz & 1.5oz fiberglass material.

Let's say i coose to use a total of 3 oz. of mat, which is better 4 x 0.75 or 2 x 1.5?

Please explain / teach me why.

I intend on grafting in 1/2 marine grade plywood to the existing fiberglass / boat.

For the most part, it's pretty flat & not too many bends needed to be made, maybe under the console is where 90deg bends will be applied.
350v_5.jpg