> has anyone ever heard of this meathod of building?

> I got the idea to make a series of laminated beams like deck beams but
> they would form the hull instead of the deck. use them kind of like you
> would a form in building a stripper but the beams would be permenent. I
> would glue the beams to a 1/8th inch peice of plywood and the hull should
> form up nicley.... right? this seems kind of wierd. and how would I get
> rocker in? I know this sounds crazy but I'm trying to build a flatwater
> squirt boat. for myself and my friend. if anyone out there has a way of
> finding volume roughly I would love some advice. thanks for any help you
> can provide.

> Dave

What you are making is a set of laminated ribs, and applying a skin of thin wood over it.

If you had a steam box, you could make the ribs from single pieces of steamed and bent wood. Same idea, but you don't need glue or clamps.

Now if yo made these ribs from freshly cut, moist, green wood you might not have to even steam them. They would bend easily, and when they dried out the would hold their shape.

Now let us suppose that you don't have 1/8 th inch plywood, but instead have a big sheet of birchbark.

Is this getting obvious yet?

You are making ribs. You can make them from laminated wood -- the thin strips are easy to bend. You can also cut them from plywood or solid wood, make them from steam bent wood strips, or bolt and glue together from pieces of scrap. The advantages of ribs are that they maintain the shape of the boat very well, and carry the stresses very well too. The skin can be waterproof fabric, or a chap tarp.

By contrast, a boat built without ribs must have a storng enough hull skin to support the boat's shape and structure. These 'monocoque' designs need some structurally strong material for the skin, and we generally use fiberglass fabric covered wood (strips or plywood).

Usually the ribs are mounted to a few strips that run the length of the boat and define the edge where the deck meets the sides, and the edge where the sides meet the floor or bottom of the hull. The top ones are similar to gunwales on a canoe, and if the bottom is rounded (as in a birchbark canoe) there are no strips running the length of the boat aong the bottom.

How do you add rocker? Assume the gunwale is straight (It doesnt have to be, but lets assume it is) Mount the ribs to the gunwale so that those ribs in the center of the boat are higher (farther above the gunwale) and those at the ends are lower. If you are making a canoe you make the side parts of the center ribs longer. If you are making ribs for a kayak and they end up being closed rings or hoops. you just have to make the ones for the center bigger, fatter and/or taller.

It is probably not as easy as it sounds. A good design is what you want. If you draw one on a computer, use a program that allows you to 'cut' the boat a any point and give you cross sectional views. The outside of your ribs should match these design's measurements.

Trying to get 1/8th inch plywood to follow the curves of your design may be a trick. I'm assuming you will cut narrow panels and apply them kinda like wide woodstrips, fitting them as you go.

Putting fiberglass on the outside of the final construction will form a seamless cover that adds a bit to strength, but primarily serves to fill minor holes and prevent leaks.

I've talked about canoes. made of birchbark because it is a close cousin to yor not-so-weird idea.Continuing along tha line of thought for a minute, make a series of deck beams and put them over a canoe and you have a kayak (well, sorta, but you get the idea.)

for your squirt boat you could make ribs for the hull, and then make separate deckbeams for the deck. OR, you could make loop shaped ribs that serve for both the hull and deck.

Once you have the frame, you can cover it as you please. Personally, I've been looking for a great glue that will stick to linoleum flooring. I can get cheap, slippery coated linoleum in 12 foot widths and who-knows-how-long lengths from any home center. If I could glue the stuff it looks like it would be a very durable covering, decorative, flexible, hard to rip, and slippery enough to slide over rocks. Just a thought.

Hope this helps.

Paul G. Jacobson