raft race boat???

[kayakn]

i need to make a cheap raft race boat for a raft race(duh) the boat has to be homemade and i want to make it cheap. i was thinking of making a flat bottom with no curve this way___ but from the top the boat will look like this <> or ()
and the sides would be 90 degrees like this L.
pretty much a canoe with no major curves.

i plan to make it very cheap. i was thinking of using 1/4 inch plywood which is cheap and using construction adhesive and (screws or nails, you choose) to hold it together. it would be about 8'.
for a paint job i would use spray paint or maybe ductape. i would probably need only one sheet of plywood if i am lucky.

my major concern will be the floor falling through. i was thinking of having the sides something like a bed frame (the slats rest on a strip of wood) but the bottom would rest on the slats.


does this sound good?

[PAR]

The fastest way to build a boat of this type is to use taped seam methods. Fillet the seams and corners, smear on the tape and call it good, after a dabbing in plane old house paint (exterior).

If you're going to race the boat, shape should be considered. Simple shapes aren't hard to build. Some rocker in the bottom panel will help maneuverability and ease rowing effort. Some curve to the sides will decrease resistance and placing a pointy end on the front of the boat has decided advantages too. A well shaped pram will out perform a concrete mixing tub shape by a large margin.

With the curved pieces you dramatically increase the strength of the panels as well. 1/4" plywood will be just fine. You'll want the structure to be as light as you can make it. The lighter it is the better it'll perform.

[rwatson]

Sheets of corrugated roofing steel make good fast boats with the bow made of two ends bent together, and the stern made of a squarish wooden section that you nail the metal to. Waterproof the ends with thick tarry stuff from the hardware shop.
It will be very fast, and wont need waterproofing or painting.

[kayakn]

so i made the boat which has no curve but to the sides and it has a flat back. i will have to add pool noodles to the sides for stability. that is how i am going to race it this year. but next year i am going to make another one that is exactly the same and i am going to connect them to make a catamaran. then i have to figure out some way to connect a shaft to the back wheel of a bike and have that go to a propeller. how should i do this?

[masalai]

"one eighth should be enough for a "one use" and 4 " or 6 " by half inch pine planks. start upside down and what will be the top is flat, if paddle powered or even small O/B cut the 4' x 8' sheet longitudally so you will end up with an 8 ft boat 2 ft wide... use woven glass and epoxy to the inside to fix the first part and add some cross braces then too. if the outside bits of pine will bend a bit make it a bit pointy at the bows... when that is set then curve up the front end by planning the edge pieces, use your glass and resin to fix the bottom on the outside and add some used paint leftover for colour..... a bracket and braces at the back to mount the outboard can also be affixed with woven mat & west system stuff again - use only a tiny outboard with integral fueltank and be prepared to "loose it or salvage it if you capsize" and HAVE FUN.....

It will be narrow enough to paddle as one would a canoe and carry two non obese people easily....