Welding Aluminum Pontoons

[ecoman]

The net and this site seems to be lacking information on fabricating pontoons themselves. I can weld aluminum, but haven't been able to figure out how to make the rear cap and nose cone.

Alternatively, I've had difficulty identifying a metal fabricator that already makes such things for pontoon boat manufacturers. Is there anywhere I can purchase pre-formed cones to weld onto the pontoon core?

[Gulf Cruzer]

Hi, Im not sure how popular pontoon boats are where you are but there are a few differnt models over here with slightly differnt pontoon designs.
Any way what Im getting at is do you really neeed a cone to cap off the end?
Ive seen boats where at the end, the bottom follows the same line but the top is cut away and checker plate welded in to form a step. It looks good and is functonal as well.
Also are you makeing round pontoons or D shaped?
I like the D shaped ones as they look good and take up less room inside the boat.

[Thunderhead19]

YES! You can buy domed ends for your pontoons! If you want to make them there is a bunch of different ways to do it! Look up draw forming! There will be a bunch of companies willing to make you a die that will stretch a piece of aluminum plate as it draws it into a female die. It can be crappy with aluminum because Alu tends to hang up in molds and tear if it is too thin. A cone is deceptively tricky and may have to be made of two halves so that you can bump it in a press break. A dome usually requires the use of an "English Wheel" or forcing the aluminum into a die. I dare say explosives work quite nicely for this - look up explosive forming or explosion forming. A creative person would be able to use electricity and water to do that. (the high voltage turns the water to steam instantly with explosive force, but you'd need a bunch of gear to set that up.)