Yes, this is the material we are talking about. Yours is pink, my is greenish, others are blueish. It depends on the manufacturer.
Maybe someone, who used it and his board survived for a longer period, will reply to this post, but I doubt it.
I am using less and less of foam. Now I use it only to fill some empty spaces inside the core. Everything else is wooden and it shouldn't be heavyer than 3,5 kg.

I thought they were talking EXPANDED polystyrene which is the white stuff that comes apart very easy. I am trying to make a board 180x 52. I made one from 1/2" birch plywood and fiberglass and it was very heavy. For this board, I have started with a 2" thick piece of foam. But maybe I am wasting my time if this stuff won't work well. What is the difference in Corecell?

Corecell is a foam that absorbe slot of the reason which makes it mut h heavyer but also gives it stiffness and im using Owens cornering for my board how do you tell the quality of the foam

tckiter

Corecell does not absorb a lot of resin or reason for that matter. It is the foam of choice for most custom builders. It comes in various densities and is designed for marine use.

http://www.noahsmarine.com/United_State ... ls-us.html

Stan

I am still unclear if I am wasting my time or not. I looked at the foam and it does say XPS.

Stan, in your opinion will this work or should I scrap the free foam an get some corecell.? In an earlier post you seem to advocate the exps. This board will be thicker than most kiteboards, like a surfboard. It is intended to be a light wind board. I learned from my plywood board that I spent alot of time and was not happy due to the weight. I am making basically an extra large Mako with concave. In order to achieve this in plywood, I cut the plywood almost all the way through in both directions then formed the shape and glassed. It rides well turns carves etc. but is heavy and slow. I also cracked it a couple times along the cuts and had to reglass. I was hoping with the foam and extra thickness and epoxy resin maybe an extra layer of glass and vacum bag this would work.

I appreciate all help. Thanks

I would say for sure get some good foam. You will waste all the epoxy etc on that crappy xps. If you were going for a surfboard then go with expanded polystyrene which is the bead stuff. The foam you have xps is extruded and it will fail. I have been through this and am saving you some time and pesos.

If you have woodworking tools like thickness planer etc you can do a wood core. Red cedar turns out to be OK for weight and strength.

The best and easiest way is this....viewtopic.php?f=107&t=2365117

You must see that.

For a long read about a collective experience of semi-pros like me read yahoo groups.

http://groups.yahoo.com/group/boardbuilding

There are years of experience there and all newbies should get there and dig in for while.

Your first board may be not so good but the next will be. Do you have any friends who build boards nearby?

Have fun
Stan

Thanks Stan. I will take your advice and scrap my started board-no money spent, just a couple hours learning how to sculpt foam. I do have a pretty good amount of woodworking tools including planers, sanders etc. This is relaxing fun for me.

I wish there was a topic about the usage of EPS in TT production and it's minuses at the time I started my first board. It would save me a lot of labour time, material expences and nerves.
By the way, I did some test samples before starting with it, but the resaults were not equivalent to the real needs. Or maybe I was 2 optimistic and hoped, that bonding and foam strenght would be better on a larger piece. Maybe they are, but so are the forces, that board has to withstand.
I f***ed up 7 of my boards because of this. Don't do the same mistake!

Like Stan said, get rid of XPS and get some better foam.

Board building isn't about saving money on kiteboards. It's something relaxing to do when the wind isn't blowing or the water is frozen over and no snow on the ground. It's also about hiding the cost of a bunch of kiteboards from your wife by deviding it out into parts. Realy though if you think about the cost of the epoxy alone it's well worth your time and money to use a good core. If you can try and find a local supply as I have found freight costs for a 4 x 8 to be quite not fun.

zob,
forgive me, if i have misunderstood you construction methods.
All of your boards appear to have plywood on the bottom and foam on the top ( with perhaps a bit of glass on top of the foam)

I dont want anyone to think i am a fan of either XPS or EPS. But you need to locate it between layers of strong stuff. specifically, the top layer of reinforcement should be as strong (or stronger) than the bottom skin.
otherwise, i dont believe you will find any advantage to using any standard foam core material.

That said, stan is the man.
so if you need to ask, try it his way first before solving problems you dont want to know about.
regards,
-bill