Floor replacement ???

I have a 1994 astro and the floor has rotted out. I have budget and time constraints. I have just about got all of the rotted floor removed from my boat and I have a few questions.

1st, there were screws holding the floor to the topcap under the fiberglass. They were about every 5 inches. Do I need to screw the floor in before I fiberglass it in place? Was this done originally for strength or was it done at the factory to hold the floor in place while it was being fiberglassed into the topcap before it was attached to the hull?

2nd, a couple of the stringers have rotten spots in them. They still have good wood, its just rotten in spots. I don't have the facilities at my disposal to lift the topcap off my boat and completely replace them. If I were to go that route I would also need to remove the flotation around the stringers and then replace it as well. I don't have the time or the money to do all that. My plan was to remove as much of the rotten stringers as possible and leave the solid parts in place. I would then pour seacast into the spots where the rotting wood was and then lay fiberglass over the top. Does this seem like the best course of action seeing as I can't replace the entire stringer?

3rd, I plan on extending the deck to the console. Is there any reason I can't just fiberglass the deck extension into the boat and then just recarpet the whole thing? I figure I can fiberglass it into the floor and the existing deck and then maybe to the console and to the side of the boat. Will this affect the structural integrity or remove any needed flex in the boat? One reason for this was so I would not have to build the deck out of 2x4's. I was thinking I could build a light weight frame and fiberglass over it, using the fiberglass for strength which brings me to another question. How many layers of fiberglass do I need to wrap around something like a 1x1 or something even lighter to give it the strength of a 2x4?

Any suggestions?

If you're able to afford seacast, then you should be able to afford the marine plywood... IMO, its better to do the job right the first time, rather than doing this n that for a quick temporary fix...

I dont know much about Astro, except that its a fiberglass boat... but I'll bet you got a big motor mounted to her...

From what I know regarding fiberglass hulls... the flooring is always glassed onto the hull... screwing it in is a big no-no... Basically you want the plywood to be completely encased in fiberglass with NO WAY for water to get in, which would start the rotting process... and if you bought it from someone else (which is what I think), I'll bet that the previous owner was the one who screwed the screws in...

I also dont think you really can get to the stringers without lifting the topcap off... if there are spots from where you can see them, chances are that you'll have few spots where you cannot see them thats rotting too...

Why dont you take some pictures of your boat... and post it up here... so that we can have a better idea of what you're talking about, and be able to help you out more...

Good luck!

I'm still going back and forth as to what I should use for the floor. I have read where marine plywood isn't much better than exterior plywood these days so I don't know if its worth paying the extra money for it. I have been toying with the idea of using something like plastic for the floor but it is allot more expensive and its heavier.

As for the screws, they really look like they came from the factory that way. I don't think the floor had ever been replaced before. Hopefully I can get some pics. I have already ripped out the floor so it will just be pics of the holes I guess. I don't think the floor was encased totally in fiberglass. My theory of what started the rotting process is the drain in the floor back by the seats. I think if the manufacturere would have fiberglassed around the inside of the hole, water would never have gotten in and rotted out the floor. That and the fact that the orginal owner left it outside and uncovered which is beyiond me how someone can spend $15,000 on a boat and leave it outside and uncovered to rot. Thats just my theory. The floor around the hole was the most rotten. The only thing keeping my foot from going thru was the carpet.

As for the stringers, there are just sections that are rotten. I have also been thinking about penetrating epoxy to fix them but there are sections that are to far gone to use the epoxy on. In those areas I was thinking of the seacast. I think I can get 1/2 gallon for $50 which should be enough tofix the stringers.

As for the motor, its a 1994 mercury 150 xr6. I am beginning to think its the only good thing about the boat.

Mercury XR6... impressive... I own a Mercury XR4... From what I heard, those XR's are such strong workhorses...

Like I said, you want to do the job right way, so that it will be "the First and the Last"... so if I was you, I would definitely stick with Marine Plywood...

From what I know, Marine Plywood has couple more plys than exterior Plywood and the process involves marine-grade glue for Marine Plywood...

The flooring on my Bass Tracker completely rotted over the area of the bilge... When I ripped it all out... I also discovered that the underside of the flooring wasnt even glassed... so I know what you're talking about...

I was hoping that Northrivergeek would chime in about how to do the stringers...
and some info about this apparently professional screw job...

From what I know... you're supposed to enclose the flooring in fiberglass, then epoxy it onto the crossbraces/stringers then glass it onto the hull... no need for screws and no worries about holes in fiberglass that would someday permit water to seep through...

Good luck!

More questions

I have been concerned about waterlogged flotation so I took a core sample. The flotation was about 6 inches thick and the bottom 1/8 of an inch had water in it. Is this something to worry about in a 15 yr old boat?

i had a while back a 1994 Stratos that i did a carpet job on and found rotten wood by drain, when i pulled floor(was screwed into stringers)found damage to stringers, so what i did was bought some treated 2x8 and glassed them, then used to scab to original stringers via allthread rod...the foam wasn't water logged so i then glassed up the new floor piece and screwd down w/stainless wood screws and coverd seams with glass. when i cut the new drain hole , i glued a 3" stub of pvc pipe to the botom of the drain to make sure water went where it should have gone..Now, when i sold the boat awhile back, i did make sure to tell purchaser what i had done and it would one day need the top half pulled of and be done right...same as you i had no place to split hull.. hope this helps

I have a 1989 Stratos that I am going to have to do the same thing, and facilities wise i am in the same situation, to but I do have a plan/ design. I could send you some pictures/drawings to help with the stringer stuff if you want it.

Anyways keep us posted with progress.

PS: from what I understand sea cast does not bond with wood well, But i may be wrong, i have looked into this myself.

goodluck

Well, I got started on it. I ended up trying to remove as much rotted wood from the stringers and then used penetrating epoxy to try to prevent further rotting. I then used a waterproof putty to rebuild the stringers which may not have been the best route but it seemed to hold up. This last weekend I got the floor in with an initial layer of fiberglass. I still have to put down a couple of layers of matte.

What a pain this experience has been. I almost think I would enjoy it if I had a shop to work in. I am doing this in my back yard. The first issue I had was that I had to cut the plywood into sections to get it to fit in place. I coated the wood in resin to give it a pre treatment and every bug in the state decided they wanted to come land on it. Then, aparently fall started to occur in my yard and leaves fell on them. Then I knocked one of the pieces on the ground. My floor looks like that amber jewlery with the insects in it.

Things I have learned from this.

1. It sucks not to have a shop with a controlled environment.
2. Order plenty of supplies online. You can get what you need from home depot but it isn't as good.
3. Invest in fiberglass tape. It sucks to try and cut your own.
4. Wear long sleave shirt and pants when sanding fiberglass or laying on a boat floor that had just been sanded even after you think you got it all up.
5. Good quality rubber gloves that can handle acetone is a must. Disposable ones work but as soon as you take them off, they are garbage.

Man, sorry to hear that, best of luck with finishing it.

Made my first attempt at laying fiberglass mat. What a nightmare. I have to do some major sanding now. I have fiberglass hairs sticking up everywhere. I have always worked with cloth and had no issues. I have watched some videos and I think I know what I did wrong. All the videos show pouring the resin on in large amounts and then spreading it around which is not what I did. Good thing I am putting carpet over it.