Interesting Home made pontoon idea (New Member)

So i've done alot of thinking. I want to build a 12' long by 8' wide pontoon boat. I've decided I want to go with at the most 6 55 gallon sealed metal drums. each drum should hold about 441 pounds if my math is right. But so far my idea is to weld 2 sets of 3 drums together for the pontoons and maybe cut the rounded part off a couple of larger EMPTY propane tanks and weld them to the front drums for hydrodynamics i guess. Any better ideas than the propane tank tops? Then i'm going to weld flat metal bars from each drum to the other. so a total of three going across. that should be plenty stout enough just for a smalish fresh water lake right? My ideas is to bolt plywood to the i guess you could say cross members? What would be the best plywood? I know marine grade would probably be best but its quite expensive. I believe 80.00 a sheet here (8x4). I want to build a 8' wide and 5' long "cock pit" just by a standard frame out of 2x4 and boxing it in with sheat metal? thats the lightest thing i can think of at the moment. I want to leave 2' in front of the "cock pit" at the front of the boat just for a place to put an anchor and things. and with the 5' cock pit that should leave about 5' of space in the rear of the boat. I've also been thinking very hard about powering the boat. I've always liked pedal boats. I just dont want it to be so heavy i cant pedal it you know? You cant put a motor on a boat in the lakes here with out it being registered. and i just dont think i can get enough distance and time out of a transom mount trolling motor and a battery.I want to try to keep this project under 1000 dollars. I could just go buy a boat but hey, wheres the fun in that right? thanks yall! After i get started ill for sure post pictures, and of course ill have a few questions I'm sure yall can answer!

 

sounds more like a floating platform. that is not a very efficient boat hull, but would make a good swimming or fishing platform. you could build a nice plywood row boat for well under $1000, why bother with steel drums? You can also make a much lighter catamaran hull with two sections of 12" plastic pipe. Or consider those 50 gal plastic barrels, wont rust.

As for wood, any reasonably clear and straight grained lumber you can get at a big box store would work for a deck on your craft. 1/2" cdx with 2x4 or even 2x2s at 16" spacing would make a reasonable floor for it. If you expect it to last a long time try using pressure treated CDX rather than marine plywood. Use galvinized nails or screws, or those plated deck screws work nice too.

set up some oars on thole pins, easy to make with hardware store parts rather than bronze ore locks and other costly boating gear.

 

pretty much what I am wanting to do is build a small fishing boat with 5 long and 8' wide cabin. Just enough for a couple chairs and things. Im new to the whole boat building but have good carpentry skills. Is there any type of pontoons i can build for lets say under 250 dollars. I need two at least 12 feet long.

 

1/4" plywood or even skin on frame hulls would make nice light, and inexpensive, hulls.

 

55 gallon drums will quickly rust through. A flat bottom skiff will be cheaper, less work, more efficient and a better overall boat.

 

Considering what you want to do, using drums isn't a practical idea. The weight will make it difficult to do anything other then fitting a high thrust outboard on it. If you want to row, pole or use low power like a trolling motor or small outboard, it has to be light and hydrodynamicly efficient. This means steel and 2x4's are out of the question. Some steel to hold stuff and maybe a couple of 2x4's, but that's about it on a boat of this size. The structural elements of a boat this size will be 1x2's not 2x4's and steel simply isn't necessary, for the most part.

Look into the "PD Goose" from Mik Storer, tell him PAR sent you.



It's a simple 12' long 4' wide box boat, designed to sail and a stretch of the PD Racer. This will give you and idea of what a boat this size will need and some general shapes to work with. The image above shows an uncompleted hull, but you should get the idea. It'll be light enough to row (or sail, which is free power) and you can use a trolling motor if desired.

An 8' wide version of this will need 4 times the amount of power to push it along and rowing will become all, but an upper body workout, so think about a narrower design. Use plywood marked with only the "Exterior" stamp, not "Exposure 1 Exterior", which is as cheap of water proof plywood as you'll find. A 12'x4' boat will need a 3/8" or 1/2" bottom and 1/4" or 3/8" sides. If you're rowing or sailing use the smaller numbers, if you'll eventually toss an outboard on it, use the thicker plywood. A 1x2 at the chines, the same at the sheer, some simple seating and you've got a boat, Use a good exterior primer and house paint and go have fun. Nope, it's not going to be pretty and the paint will start peeling in a few years, but it'll be your designed and built boat. A boat like this can be lifted (easily) into the bed of a pickup too, so it can go places without a trailer, so think about what you really need, what's practical and most importantly, usable. A 12'x8' will be too heavy to lift and probably too heavy to row as well, so now you need a trailer, a motor, registration and all the rest.