Pontoon Hull Question!!!

[Sceptre]

ive been going through this website and looking at posts and no one can tell

wats the best way to build a pontoon hull do i take aluminum and weld it then airseal/waterproof it ?

or do i weld the aluminum and then put foam inside and what foam exactly ? the hard one u can brake into pieses or the one they sell compressed in liquid form like 150$ for 4L at homedepot

is it best to waterseal it or fill it with foam?

everyone is invited to share his opinion

wats the final word on making a good hull for 16'ft boat that will hold a wooden deck 120inches on 200 inches with atleast 13 ppl on top

[PAR]

A welded aluminum pontoon, doesn't need foam, nor do the vast majority of manufactures install foam (I know only one that does). Baffles and bulkheads are a good idea, but also not necessary if the shell is of sufficient gauge plate.

[the1much]

im with Par,,and want to add sumfin,,hehe ,,,what happens if you have a "mishap" and bust a leak in ya pontoon,,without foam= , ya pull ya boat,,empty,re-weld,,and go on ya way,,,,with foam= pull ya boat,,empty,,pull out ya foam (foam that has been wet has NO flotation value worth 2 cents,,and all foam makers will tell ya that) ,re-weld hole,, make notha hole on top to pour new foam, and go again,,,(and trust me,,taking out foam is 1 of the worst jobs there is),,and i know ya thinking," how bout just leaving the old foam,,ta hell will flotation value",,well,, it would probably take ya 6 months to dry it out,, and get all the water out,,or,,you could add weight to otha side to get the boat balanced again,,hehe ,,i think foam is WAY over rated,,cept to use as a "form",,and i dont think it would do anything other then ADD weight to ya boat.
my 1.6 cebts worth hehe

[Ike]

I agree with both Par and The1Much. No foam. Weld pontoon together, put in two or three bulkheads, that way it's chambered. If one chamber gets a leak, so what, you have two or three more.

[PAR]

There are a lot better ways to make a boat then to build pontoons, which aren't particularly efficient shapes for boats and require additional power to drive, then more conventional hull shapes. What are you looking to do?

[Sceptre]

im looking to make a pontoon or a big catamaran the main idea is to have a deck that ppl can jump off from and sit down at just to go to the middle of the lake i think welding aluminium hulls is a good idea can anyone recomend how i should do that and what type of aluminium to use ?

[Village_Idiot]

If you do decide to use foam, make sure it is closed-cell http://www.jgreer.com/Foam%20Page.htm

I've always wondered why they don't make the aft end of the pontoon pointy like the bow. As there is no motor mounted on the typical pontoon, why can't it be shaped more like a canoe and thus greatly enhance hydrodynamic efficiency (less drag). Much better displacement efficiency = better speed and higher mpg. Add a plate along the bottom if it needs it for planing efficiency.

Btw, triple pontoons are best, with an outboard engine mounted on center pontoon. This center pontoon should have a flat bottom at the stern for best outboard prop efficiency (planing).