Soft Spot in Floor of '01 Sport

[steve-o76]

I have a 2001 Sport Nautique and noticed a soft spot in the floor this past weekend. The soft spot is located about ten inches in front of the rear seat, halfway between the motorbox and the siderail. It's not an area that fells 'broken', but instead just seems to give a little bit, unlike the rest of the floor.

The area is a higher-use area becuase it is where most folks are inclined to step down when entering the boat. I'm pretty good about allowing the boat to dry out before covering it and can't figure out exactly what is causing this. More importantly, I'm concerned with the magnitude of the problem and what I can do to stop the spread of the soft spot and fix the existing problem. Also, is this a common issue for boats this young (or older boats for that matter)?

Thanks in advance,
Steve

[ag4ever]

RE: Soft Spot in Floor of

Sounds like a rotten floor. My dad's old ('79 outboard) had this happen a few times. He has had the floor replaced twice, and has just left it alone for the last 15 years with the most recent rot. So far it has not gotten much worse, so I would say just monitor it, and if it spreads, fix it, otherwise just live with it.

[ccskier16]

RE: Soft Spot in Floor of

I hope its not rotten since wood has not been used since 1991...

[bkhallpass]

Re: RE: Soft Spot in Floor of

I hope its not rotten since wood has not been used since 1991...

91??? I thought it was 93 when CC went to 100% glass?

BKH

[DRAGON88]

Re: RE: Soft Spot in Floor of

I hope its not rotten since wood has not been used since 1991...

91??? I thought it was 93 when CC went to 100% glass?

BKH

93 was the first non wood nautique years. They might have been using glass floors though in 91+... I know that in 93 they went to an all composite stringer system though...

my 99 sport's floor had some of this, and the floor behind the drivers side was a little unlevel, not shure why though, last I knew they glassed the floors on top of everything...

[OldFart]

RE: Re: RE: Soft Spot in Floor of

Even in the OLD days they fiberglassed over the stringer.

[Dr.John]

RE: Re: RE: Soft Spot in Floor of

The panel you are talking about IS a plastic sheet product. I was just talking with a guy who runs a ski school and his '02 Sport has the same problem. His, as you might guess, get some heavy use, and sits out alot.
That section can be removed easily to service the drive train and exhaust. I would guess that you could replace it with wolmanized plywood if you didn't want to go OEM.

[ag4ever]

RE: Re: RE: Soft Spot in Floor of

OK, since it is not wood, could the plastic just be breaking down over time?

My dad had the floor filled with foam, and after that the floor was always more solid, even when it started rotting. If it is outside the removable panel, can it be filled with foam to give it more support?

[DavidF]

RE: Re: RE: Soft Spot in Floor of

A bit of info on how the boats are constructed. The floor is simply a fiberglass composite laid over structural foam. The foam is what supports the floor. The fiberglass floor is relatively thin at about 1/8", so it has not strength to resist bending, so the foam does all the work. I imagine that the foam has been slightly compressed in the area people mostly jump in the boat and the fiberglass floor has let go of the foam or more precisely delaminated. IMHO, if the fiberglass has not cracked, which would let water in, then it is really not a issue that will cause harm other than being unnerving.

So, how to fix? Best way would be to peel the carpet off and out of the way (hard to do without destroying carpet, but with a razor blade, time and patience, it can be done). Then cut out the delaminated portion of the fiberglass floor. Lay-up a patch until you have built up the composite to the original level. Grind it flat and smooth (use Bondo on low spots) and reglue the carpet. If you go this route, you will need to know a few more things to do it right, so just ask.

If you are talking of the center removable section, then it can simply be replaced, but I find it hard to comprehend how it would have been broken.

[Dr.John]

Re: RE: Re: RE: Soft Spot in Floor of

If you are talking of the center removable section, then it can simply be replaced, but I find it hard to comprehend how it would have been broken.

What I saw and was referring to earlier was indeed the removable center piece. I just don't know the exact materials/construction used.

[alanholt]

RE: Re: RE: Re: RE: Soft Spot in Floor of

The centre section of floor that houses the round inspection cover broke on our '01 Air Nautique, its made of black plastic and hollow I think. It was cracked around the round hole on the bottom and flexed when stood on. I took it out and pop rivetted a sheet of aluminium to the underside, it still flexs slightly but is a lot stronger.

[steve-o76]

Thanks to everyone for the advice. I think DavidF has put me at ease with describing the makeup of the boat and the most likely cause of my problem. I'm going to wait until the "off-season" to address the issue, but I'm now confident that everything should be fine for the time-being. Thanks again, guys.