Styrofoam

[gonzo]

They use to make sailboats made out of solid styrofoam. The softboards (surfboards) are styrofoam covered in some kind of fabric. I saw a kayak carved out of a huge block of styrofoam. I think it gives you an cheap and easy way to experiment with shapes. You can glue more foam or carve some off.

[boat fan]

Originally Posted by gonzo

They use to make sailboats made out of solid styrofoam. The softboards (surfboards) are styrofoam covered in some kind of fabric. I saw a kayak carved out of a huge block of styrofoam. I think it gives you an cheap and easy way to experiment with shapes. You can glue more foam or carve some off.

Yes it would shine if you wanted to alter shapes quickly and easily.
Carve away as much as you want.......
Often it`s used for prototype development for those reasons.

Surfboards do use styrofoam cores but not all .Quite acceptable for something that does not spend that much time in the water after all.
Styro cored surboards do break easier than the polyurethane cored ones. Stringers are sometimes placed in the centre.

I would rather still choose a well designed kayak for my needs and build in a more conventional method.

[Herman]

And about polyester resin and styrofoam: There are certain types of polyester resin that will work. They are not common, you will have to search for them, but there are some available.

In Europe, I know of 2 places to get it: Nord Composites in France, and Brands Structural Products in the Netherlands.

[frankseales]

I tried the method you were thinking of but i covered the styrofoam with epoxy and micro-baloons first to try to protect the styrofoam fro the polyester resin. The polyester resin still managed to get through the epoxy and attack the foam but all in all it worked. I think a better idea would have been (and ill try that next time i build a kayak) to make a mould with ply in roughly the shape of the kayak and use the 2 part PU foam. This way you can make the foam whatever density you want and use straight polyester resin. Also i did the volume calculations and it would be cheaper to get the core this way rather than buying a block of styrofoam as i did. Also epoxy resin is much more expensive than polyester resin so cut costs again.
Here is a link to the photos of the build process
http://www.facebook.com/album.php?ai...5&l=3e4e01d5c0

[Steve W]

Herman is right, duratec is one maker of a polyester for use on styrofoam.
Steve.

[ondarvr]

You can also buy it from Composites One, the demand for products like this is low, so it will need to be ordered.

[pcfithian]

Originally Posted by gonzo

Styrofoam works well as insulation. We have also used it extensively on hard tops and decks as a core between thin plywood. We used epoxy as an adhesive. The close cell polyurethane is rated for ground contact.

Thought it might help to link this thread, Extruded Polystyrene (XPS)

to this discussion. XPS foam is available in green as well as blue and pink.

[Mr Efficiency]

Discussing the utility of various foams is advanced somewhat by more attention to the densities that are available, low density may be of no use in some applications but perfectly adequate in others, condemning a type of foam without reference to grade ( read density ) is often misleading.

[grigerar]

Hi, I had once a high density styrofoam sailboat (8 foot or so) I bought second han and it was great!

[tunnels]

Originally Posted by werwer6969

I'm interested in building a boat out of rigid styrofoam and covering it in fiberglass. I was wondering if anyone can tell me if this would work or will the fiberglass eat away at the styrofoam, any help anyone can give me would be greatly appreciated.

Greg

USE EPOXY RESIN !!!

[rasorinc]

Stryofoam does not react to epoxy. It is OK to coat it with epoxy. Stryofoam does react to direct sunlight. It needs to be protected from [UV] rays and epoxy does not do that-but paint over epoxy can.

[tunnels]

Originally Posted by rasorinc

Stryofoam does not react to epoxy. It is OK to coat it with epoxy. Stryofoam does react to direct sunlight. It needs to be protected from [UV] rays and epoxy does not do that-but paint over epoxy can.

Paint the epoxy with a barrier coat then a top coat !!

[PAR]

Originally Posted by tunnels

USE EPOXY RESIN !!!

Did I read this right?

[tunnels]

Originally Posted by PAR

Did I read this right?

Ummmm not sure !

[waikikin]

Originally Posted by tunnels

Ummmm not sure !

It quite plainly & noisily suggests to use epoxy resin on styrofoam the way I read it, thats what you wrote, I'd use it too