New guy, floor repair questions

[Racer223]

And just so you don't think I'm a total wanker, here's some other progress I made:
Back in August I pulled all the cushions out and took them completely apart. Turned out they used crap plywood and regular stapes and when it started falling apart someone just poured caulking into every hole. Once I cleaned up the sealer and separated the foam, vinyl and plywood I realized that everything except the plywood is in good shape (aside from the sealant residue) and it's not a difficult fix. I bought few pieces of Azek of various thickness and cut all the cushion bottoms out of it, bought marine grade staples and just put it all back together, came out better than I expected.




I also did some work on the trailer, the bunk board supports were too short and getting bent at the bottom, so we made some new ones using square tube, milled out the slots and left the bottom a solid so it doesn't spread again, new carpeted boards, wider rollers and improvised guide-ons made form what I had on hand, just need to add the bunks or put some PVC pipe over them so they don't scratch the boat.
Can't wait to get all this done so I can get out on the water soon

 

[airshot]

Fiberglass boats back in those days have a wooden skeleton over which the fiberglass is layed. If you remove the skeleton, the fiberglass will give and cave in !! Boats rot from the bottom up....this means if your floors are rotten, the skeleton under the floor is even worse ! All that rotten wood needs to be cut out and removed, then new wood needs to be glass bedded the glasses over to get the skeleton strength back or your hull will crack and crumble and your boat will sink ! Wish I had better news, but your boat is an accident looking for a place to happen without serious and expensive work !

 

[Racer223]

Fiberglass boats back in those days have a wooden skeleton over which the fiberglass is layed. If you remove the skeleton, the fiberglass will give and cave in !! Boats rot from the bottom up....this means if your floors are rotten, the skeleton under the floor is even worse ! All that rotten wood needs to be cut out and removed, then new wood needs to be glass bedded the glasses over to get the skeleton strength back or your hull will crack and crumble and your boat will sink ! Wish I had better news, but your boat is an accident looking for a place to happen without serious and expensive work !

I have drilled a hole in the floor with holesaw and found ZERO ROT, I'm not willing to perform an autopsy on a "living patient" just to prove there was no cancer, just looking for an ideas what kind of foam and where to get it, this is just to fill a void that is 1" deep on the sides where plywood ends, once again, THERE IS NO ROT, looks like fiberglass sagged and cracked where plywood ends, you can see the cut made in the plywood that was there when I opened the floor

 

[airshot]

The rotten wood stringers and supports are enclosed inside the fiberglass. Your floor is buckling because the skeleton inside the fiberglass is rotted. Being a trihull, they used plywood covered in fiberglass with a chopper gun which added little strength to the hull. Your boat, your call, but I would not take passengers onboard if you use it as is.

 

[Baylinerchuck]

You have to be careful when pouring foam in a cavity like that as it could push that floor up and cause a bigger issue. You would be better off filling the crack with thickened reinforced resin, grinding down to good clean fiberglass, then doing a couple layups of CSM tying the repair into the gunwale. If you do decide to throw some foam at it anyway, I would use the 4lb pour in foam since the repair is structural. You would still need to go over everything with a few layups of glass.

Since you do have some holes opened up in the floor, make sure you look at those stringers and substructure. Look as close to the transom as possible. Make sure you check the transom. Any hole you drill as an inspection can be filled with reinforced thickened resin, (hairy peanut butter). You don’t need to hole saw massive holes as they are harder to fill, 3/8” drill bits will tell the story clear enough.

Good luck, and please keep updating as you proceed.

 

[Racer223]

You have to be careful when pouring foam in a cavity like that as it could push that floor up and cause a bigger issue. You would be better off filling the crack with thickened reinforced resin, grinding down to good clean fiberglass, then doing a couple layups of CSM tying the repair into the gunwale. If you do decide to throw some foam at it anyway, I would use the 4lb pour in foam since the repair is structural. You would still need to go over everything with a few layups of glass.

Since you do have some holes opened up in the floor, make sure you look at those stringers and substructure. Look as close to the transom as possible. Make sure you check the transom. Any hole you drill as an inspection can be filled with reinforced thickened resin, (hairy peanut butter). You don’t need to hole saw massive holes as they are harder to fill, 3/8” drill bits will tell the story clear enough.

Good luck, and please keep updating as you proceed.

Thanks!

I can stick my head under that tray in front of the engine and see the back of transom and drain plug, looks good to me, no bubbling or anything like that. those 2 large holes I drilled upfront was for ventilation while it's drying out, wanted to move air through the whole hull.
I have a friend with a high end camera we use to inspect the cylinders and other tight spaces so I'll drill holes that are just big enough for the camera to fit through and inspect the whole floor if I can.
I was thinking maybe I should remove that whole corner area that sagged and instead of trying to force the foam inside it just start over with some plywood and fiberglass, would be easier to support it rather than trying to force something in? it doesn't seem to be sructural as it's only a think later of fiberglass and whole lot of some kind of greenish filler (bondo?)