Modifying an inflatable with a one-piece floor

[retrosub]

I have a 14' inflatable and I don't like the floor it came with, it's too slippery and very heavy. I don't need to take the floor apart (the boat will sit on a trailer), so I'm thinking about making a new floor.

The rear four rectangular sections of the floor connect to create a solid unit approximately 48" x 72", and there are two front sections that slot in and are designed to bend (hinge).

It would be quite easy to make a 48" x 72" floor from a piece of plywood, thereby avoiding all the metal hardware in the interconnecting sections. I'm also considering a composite structure, maybe 1/4" thick wood on top, and then a layer of foam and fiberglass. I'm open to ideas, but the floor should be about 3/4" thick if I want to use the existing hardware to attach to the front two sections.

And I'm also wondering if I can make a one-piece floor without the hinged front sections. Would there be any problem if I made a floor that had a gradual curve in the bow rather than the hinged sections? My guess is that such a one-piece floor would ride a lot better. I would probably also put less strain on the tubes (they won't bend with every wave) but might put more stress on the seams. Then again, the bow could be designed to flex a little bit, but gradually over the length rather than at just two hinges.

I've looked around on the web and can't find anyone that's done a one-piece rigid floor. Advice?

[marshmat]

Welcome aboard, retrosub.
I'd be worried about making the boat too rigid. Soft-bottom inflatables are designed to flex like crazy as they go over waves, that's how they absorb the energy of the wave. So I would keep the hinging up front. If you want something significantly lighter than what you have, wood won't do it- you'd need to go to a CoreCell or similar foam core with fibreglass skins.
What make/model/year is the boat?

[retrosub]

This is a Baltik 14', PVC not Hypalon. I bought it this summer brand new on eBay for $800.

I may weigh the floor sections, you would not believe how heavy they are. I think replacing the four pieces that make up the 48" x 72" section with a single piece of plywood may decrease the weight by 20 pounds or more. But you're right, a composite is even better. I was going to make my own, as I have fiberglass and resin taking up space in the garage.

I looked up Corecell and found it on jamestowndistributors.com, expensive stuff. I've worked with Divinycell before, which is a little cheaper, I wonder what the difference is? I also found Jamestown have epoxy coated balsa wood, and that would be cheaper still. I would save about 5 pounds using the high-tech materials over balsa.

Thanks for the leads.

[bretticus]

what I would use and have is some coosa composite. This is impervious to rot and will last the lifetime of the boat. You can find them at http://www.coosacomposites.com/
Hope this helps!

[marshmat]

Looks to me like it's just fibreglass and foam mixed together.... to make the best of these materials, one would usually put the fibreglass as skins, far from the neutral surface, where they will have the greatest possible stiffening effect. That's not really a cored board, it's more like a solid laminate with urethane foam in place of resin. An improvement in rotproofing over plywood, but not comparable to a sandwich panel.

[bretticus]

this stuff is amazingly stiff and tough depending on which type and thickness you get. The bluewater series is the highest density and comes in thicknesses up to 1/2". It is very workable and finishes great. I made several consoles and floor panels out of this stuff. Kind of expensive but you will never have to replace the panel again.

[kach22i]

How do you connect the panels to each other?

1. Butt joint

2. Lap Joint

3. Tounge & Groove

4. Center Spline