Floor Layup Question

I am working on my my 85 SN project, I just about have all of my foam in and shaped and had a question about the floor glass layup. When you lay the glass do you lay the glass from the edge of the hull to the edge of the stringer then use glass strips to go up the hull and down the stringer or do you just use one piece of glass to run from up the hull down across the floor and down the stringer?

Here is my planned layup. (Up the hull and down stringer I am not sure if it will be the same sheet of glass yet. Depends on the response I get)

Layer of mat edge of hull to edge of stringer
fillet around edge of hull with thickened epoxy.
Layer of biax 2" up hull across floor and down 2" stringer.
Layer of biax 4" up hull across floor and down 4" stringer.
Layer of mat 6" up hull across floor and to the bottom of the stringer.
Layer of cloth 8" up hull across floor and to the bottom of the stringer.

What are your thoughts? I think that should give me somewhere around 1/4" - 3/8" thick floor (Above foam) with good solid joints at the stringer and the hull.

That layup would not give you 1/4"+ of thickness, but that would be really unnecessary anyways. Putting that much glass over the entire floor would take an exorbitant amount of resin.

I am assuming you are using glass directly over foam- same as the factory, right? CC made the floors ~1/8 - 3/16" thick, which is plenty- especially when using epoxy. (If using a wood floor, then disregard the following.)

Biax is probably overkill, but other than being expensive and a little difficult to work with (due to its thickness), it will work fine. If you havent ordered the material yet, I would probably opt for just cloth and mat on the floor. 5 layers (mat/cloth/mat/cloth/mat) would probably be a good layup. Either way, I would start and finish the layup with mat, not cloth (keep the mat side of the biax up on the last layer if thats what you use). That will give you the smoothest finish to carpet against. Extending a little further up the hull (and down the stringer) with each successive layer is a good practice- though going a full 8" up the walls is probably overkill. Overlapping by an inch with each layer would be more than enough. If you can cut your pieces accurately enough to extend from hull wall to stringer in one piece, then that would be ideal... your biggest obstacle will be getting the thicker materials (biax, etc) to make the bends. If you piece it together, thats fine too- just overlap the edges by an inch or 2. No need to put down a layer of mat before filleting the edge- that fillet is simply there to keep the glass from doing a hard 90... Id fillet right on the foam. Just keep the fillet relatively small.

gun-driver wrote: Papa, As long as you tie the stringers/floor/wall together you'll be OK. I wouldn't fillet along the wall as you want a close to 90* corner as possible for your carpet molding strips. Make sure you get a good lay-up on the walls, I've seen a lot of floors that separated from the walls (including my '85)

Yep my floor seperated as well on both side almost the length of the boat, that is what got me into all of this fun.

TRBenj wrote: FYI I put a small fillet on our Coosa floor/wall joint, then put 4 layers of cloth (3 tape, 1 sheet on the entire floor) and one layer of mat over it. No problem with the carpet trim, even with super thin carpet. That glass is likely to make a radius no matter what you do- putting a small fillet assures that its supported by something solid (thickened resin) rather than air. If you dont want to go with the 5 layer alternating mat/cloth layup I suggested, then I would go with something as similar as possible (Im sure youre aware that biax is cloth/mat sandwiched together). Something like 2 layers of biax (all mat side down) followed by a final layer of mat would be pretty comparable.

OK so I think I am going to do your suggested layup and throw in a layer of biax in the middle. I have it so I might as well use some of it. If not all it will do is sit around in my garage until I find something else to glass up. Or my wife to fuss at me about one. I am fine with erroring on the side of strength. You never know when I may want to throw a few extra fat sacks in, or have a boat full of people jumping up and down or whatever else may happen. If it is a few pounds heavier so be it.