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Styrofoam and epoxy-asking for a friend

Posted: Sun May 12, 2019 9:10 am
by OrangeQuest
He wants to build a portable, floating dock to launch kayaks and canoes along a ever changing banks and locations. He already have the blocks and he was wanting to keep the dock as light as possible so it can be broke down and hand carried from location to location. Has to be big enough for up to 3 people to stand on at the same time but stable enough not to roll if two of them are to close to the edge like when getting into or out of a boat.

The blocks are strong enough to stand on without denting or falling apart so the glass/epoxy would be to keep the foam from being damaged from transporting and heavy things from breaking the foam apart.

If they were made into 4' X 4' blocks that use 2" PVC pipe that locks them together that also serve as grab rails, would that be stable enough between the joints? The pipe would slide down into sleeves epoxied into the foam. He understands that the glass will delaminate from the foam but if the top and sides were thicker and a thinner bottom would that help hold it all together?
Like I said, asking for a friend. :roll:

Re: Styrofoam and epoxy-asking for a friend

Posted: Sun May 12, 2019 10:39 am
by fallguy1000
The trouble is the edges of the styrofoam and despite what he says; it does compress.

And styrofoam does suck in water, so if not closed in; it becomes temporary.

The best way to build this would be to box in the styrofoam in luan all the way around using foamboard glue.

Then you would be able to glass, but the edges of the thing would need some radius and that defeats the luan.

So, then you would decore and fill the edges with thixo and that is where you could add fastenings.

But a lot of work to build properly and avoid delam from foot traffic, and saturation from ingress.

Re: Styrofoam and epoxy-asking for a friend

Posted: Sun May 12, 2019 3:30 pm
by OrangeQuest
The thin plywood would be cheaper than the thicker glass and epoxy and it only needs to be on the deck and the side that the boats would hit? Could expanding foam be used to stick the ply to the foam and then coat with glass to seal and protect? Then under side and the sides that connect to other blocks would not need the ply. He is wanting to keep it as light as possible so it can be carried in pieces by one person.

You can stand on the foam without leaving a dent in it if you are wearing deck shoes or other that are flat bottomed.- is what he meant!

Re: Styrofoam and epoxy-asking for a friend

Posted: Mon May 13, 2019 12:19 am
by TomW1
Styrofoam is purohited in some watersheds. I know it is in the Mississippi. Coating it with epoxy and fiberglass will only delay the process as it will break away from the foam. Here is something to consider that will last a lot longer than your Styrofoam. https://www.amazon.com/24-Dock-System-F ... ay&sr=8-12

Tom

Re: Styrofoam and epoxy-asking for a friend

Posted: Mon May 13, 2019 1:31 am
by fallguy1000
TomW1 wrote:
Mon May 13, 2019 12:19 am
Styrofoam is purohited in some watersheds. I know it is in the Mississippi. Coating it with epoxy and fiberglass will only delay the process as it will break away from the foam. Here is something to consider that will last a lot longer than your Styrofoam. https://www.amazon.com/24-Dock-System-F ... ay&sr=8-12

Tom
I generally agree with your sentiment, however, foam encapsulated on all sides with luan and a glass of 12 oz or higher would avoid ingress.

The trouble is eventually the glass will wear. Ingress is likely, and floating barrels would have been easier and longer lasting.

Re: Styrofoam and epoxy-asking for a friend

Posted: Mon May 13, 2019 1:32 am
by fallguy1000
And the link you shared is also a much simpler method I wanted to add.

Re: Styrofoam and epoxy-asking for a friend

Posted: Mon May 13, 2019 7:40 am
by OrangeQuest
Here are a few pictures of what he is thinking. Very portable, instead of sheets, recycled foam blocks that snap together so they can be carried and deployed daily. This is one that is 8' X 4' X 8".
4760
4761

Re: Styrofoam and epoxy-asking for a friend

Posted: Mon May 13, 2019 9:00 am
by fallguy1000
Try a couple different ways..

I would try the luan and I would try just neat coating it.

You can also try a notched trowel method where you run thixo over the foam where you walk on it and then sand it flat and then fill in the grooves for some thicker top that will take foot traffic better.

Then just neat coat the sides that are smooth.

It all sounds like a lot of labor and epoxy cost vs an air filled chamber though.

Re: Styrofoam and epoxy-asking for a friend

Posted: Mon May 13, 2019 10:49 am
by OrangeQuest
Fallguy, if I used the luan on the top and sides then covered with 12oz. biaxial 45/45 on all sides and bottom would that be enough? Was thinking thin EVA foam to cover the deck and add traction when it gets wet.

BTW, the picture is sheet foam covered with a canvas bag.

Re: Styrofoam and epoxy-asking for a friend

Posted: Mon May 13, 2019 1:50 pm
by fallguy1000
OrangeQuest wrote:
Mon May 13, 2019 10:49 am
Fallguy, if I used the luan on the top and sides then covered with 12oz. biaxial 45/45 on all sides and bottom would that be enough? Was thinking thin EVA foam to cover the deck and add traction when it gets wet.

BTW, the picture is sheet foam covered with a canvas bag.
I think that would work.

Like all things epoxy and cheap plywood; you need to avoid ingress or the luan will delaminate most likely.