Thread: Pontoon Dingy build.

VC I am interested to know if you plan to fill the cavities with polystyrene?

Originally Posted by Rushy

VC I am interested to know if you plan to fill the cavities with polystyrene?

Shit no! Very bad idea.
They are/will be sealed cavity with a very small bung (6mmbolt) that will basically never come out unless welding on the pontoon (so they don't blow up with the air expansion from the heat)


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Originally Posted by veitnamcam

Shit no! Very bad idea.
They are/will be sealed cavity with a very small bung (6mmbolt) that will basically never come out unless welding on the pontoon (so they don't blow up with the air expansion from the heat)


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You may wish to say why you don't want to ( sweating, corrosion, weight up top due to water, etc...)

What about that 2 pack closed cell poly urethane expanding stuff ?

Originally Posted by Beaker

You may wish to say why you don't want to ( sweating, corrosion, weight up top due to water, etc...)

What about that 2 pack closed cell poly urethane expanding stuff ?

All of those you mention but welding a highly flammable material into a sealed container is essentially making a bomb that will likely see you spread all over the roof of your bosses workshop.

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Originally Posted by veitnamcam

All of those you mention but welding a highly flammable material into a sealed container is essentially making a bomb that will likely see you spread all over the roof of your bosses workshop.

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Agreed but only if you put it in before welding is finished.
Bit of devil's advocate here, as I wouldn't put it in a good sealed/chambered pontoon either.

Originally Posted by Beaker

Agreed but only if you put it in before welding is finished.
Bit of devil's advocate here, as I wouldn't put it in a good sealed/chambered pontoon either.

How would you put it in after?

Originally Posted by veitnamcam

How would you put it in after?

Expanding foam and a bung???

Originally Posted by veitnamcam

All of those you mention but welding a highly flammable material into a sealed container is essentially making a bomb that will likely see you spread all over the roof of your bosses workshop.

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@veitnamcam

That was my thoughts too.

Cheers
Pete

Originally Posted by veitnamcam

Shit no! Very bad idea.
They are/will be sealed cavity with a very small bung (6mmbolt) that will basically never come out unless welding on the pontoon (so they don't blow up with the air expansion from the heat)


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Why a bad idea? To my non technical mind if your pontoon gets a hole (however that might happen), it will leech water into the cavity and cause a list when it fills up but if the cavity is full of polystyrene then bugger all water could enter because the the polystyrene is displacing the air in the cavity.

Originally Posted by Rushy

Why a bad idea? To my non technical mind if your pontoon gets a hole (however that might happen), it will leech water into the cavity and cause a list when it fills up but if the cavity is full of polystyrene then bugger all water could enter because the the polystyrene is displacing the air in the cavity.

If a pontoon gets a hole it will likely be at the bottom,if it is at the bottom it can only fill x amount before it has compressed the air inside enough to equal the water pressure and it will not fill anymore(fill the sink and lower a beer glass upside down into it and you will see what I mean),also one is unlikely to hole a pontoon while stationary (when it could possibly fill with water and be an issue), there will be 4 separate sealed chambers so even if say one developed a crack while underway and filled while fishing at anchor while I would be pissed at my shoddy design it still wouldn't sink or even get close to sinking.

The reason I went with a pontoon design is so if swamped(short transom remember) or I have been a dick and take a greeny over the bow it will want to float upright and should be bailable/restart motor fuck off etc.

Pontoons themselves do absolutely nothing for stability until you get in a situation where there is lots of water on the inside of the boat...then they work.
The "stability" people rave about with their various pontoon hulled boats has absolutely nothing to do with the pontoons, hull shape gives(and takes away) stability.