Thread: Pontoon Dingy build.

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.

Sent from my SM-G800Y using Tapatalk

I reckon bin the 8hp and go more this way


Sent from my SM-G930F using Tapatalk

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)


Sent from my SM-G800Y using Tapatalk

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 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.

Sent from my SM-G800Y using Tapatalk

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 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.

Originally Posted by Shearer

Expanding foam and a bung???

2 bungs.

Originally Posted by Shearer

Expanding foam and a bung???

Be OK if you never wanted any welding done on the boat ever again, crack it/scrap it.

FYI for all of you.

If you crack your alloy boat somewhere and would like it fixed DO NOT SILICON UP THE CRACK!

Just let the fucker leak untill you can get it fixed, in an emergency Kneed it or similar will do but silicon in cracks will basicly tripple the cost of any repair and the repairer will call you a cunt behind your back....so now you know ay

Originally Posted by veitnamcam

Be OK if you never wanted any welding done on the boat ever again, crack it/scrap it.

FYI for all of you.

If you crack your alloy boat somewhere and would like it fixed DO NOT SILICON UP THE CRACK!

Just let the fucker leak untill you can get it fixed, in an emergency Kneed it or similar will do but silicon in cracks will basicly tripple the cost of any repair and the repairer will call you a cunt behind your back....so now you know ay

Duck tape is a magical product.

Is bitumen tape safe?

Originally Posted by Tommy

Is bitumen tape safe?

Bitumen is not awesome to weld either but I would take that over silicon especially a tape Ie not forced into the crack itself.

Originally Posted by veitnamcam

Be OK if you never wanted any welding done on the boat ever again, crack it/scrap it.

FYI for all of you.

If you crack your alloy boat somewhere and would like it fixed DO NOT SILICON UP THE CRACK!

Just let the fucker leak untill you can get it fixed, in an emergency Kneed it or similar will do but silicon in cracks will basicly tripple the cost of any repair and the repairer will call you a cunt behind your back....so now you know ay

Brings back memories. 'Its only a couple of wee cracks boss' 'Yep, and I'm going to have to cut and patch all this to make good again'. You could see their arms shrink, and pockets get deeper, then try and tell you how to do it differently.

nooo never fill pontoons

6mm bolt? why not a plastic removable bung like senator use?
open it on a hot day and get that satisfying hiss
but mostly because of dissimilar metal reaction

6mm bolts are effectively free and indestructable.

Sent from my SM-G800Y using Tapatalk