polyurethane and epoxy

is it possible to use a standard polyurethane blanks ( i.e. a Clark blank) with an epoxy resin. i notice most people use EPS with epoxy. My application is for a carbon fiber board using prepreg carbon fiber on a clark blank. why doesnt anyone use epoxy on regular blanks? i know i am asking for more trouble using prepreg carbon, but for now i am wondering if i have to use EPS for some reason.

…Epoxy + Clark = OK… …Poly/Styrene + EPS = MELTDOWN

1)UV yellowish epoxy board quickly giving damage to it. Polyester resin resists UV much better than epoxy board. 2)Epoxy resin is more expensive than polyester. 3)Epoxy resin is hard to sand into detail. 4)Well just take your carbon fiber board as an example, think what’ll u do after glassing. I like epoxy resin cos it’s only the best in here. No stinky smell, your neightbor wont complain. Its relative stiffer, stronger and more resist to ding & dent. But I dont want my boards look like those from Surftech. Regards, Crabie. http://www.swaylocks.com/links/pages/Materials_and_Supplies/

With carbon fiber cloth, the yellowing that is frequenty associated with epoxy resin shouldn’t be a big deal - I mean the board is BLACK already isn’t it? Also, I have found that epoxy/carbon fiber sands easily. I’d be careful about leaving it in the sun or in a car. It’ll get hotter than hell and epoxy can soften in heat maybe leading to delam/bubbles?

is it possible to use a standard polyurethane blanks ( i.e. a Clark blank) > with an epoxy resin. i notice most people use EPS with epoxy. My > application is for a carbon fiber board using prepreg carbon fiber on a > clark blank. why doesnt anyone use epoxy on regular blanks? i know i am > asking for more trouble using prepreg carbon, but for now i am wondering > if i have to use EPS for some reason. You can use epoxy on almost anything, including polyurethane blanks, why I don’t use this combination is: a. price of the blank, b. total weight when finished and c. foam density. (not that eps is harder but I use hardfoam over it before it’s glassed). You sure add a lot of stiffnes by using Carbon or Carbon in combination with Kevlar or even better Dynema, but ask yourself do you want your surf board to be this stiff and light. Personally for windsurf boards (or kite boards) yes, surfboards no, not worth the money and effort. Peter Rijk.

1)UV yellowish epoxy board quickly giving damage to it. Polyester resin > resists UV much better than epoxy board. 2)Epoxy resin is more expensive > than polyester. 3)Epoxy resin is hard to sand into detail. 4)Well just > take your carbon fiber board as an example, think what’ll u do after > glassing. Your can prevent the UV problems with a varnish. If the board still yellows it propably not getting weaker as the yellowing is an ongoing curing which is actually strengtening the board. Or just do an opaque lam job. I actually found it easier to sand then polyester, but no matter how fine a grit you use you’ll never get that shiny surface of a polyester board. Maybe that’s what you meen. The cons - the resin is expensive. If you’re after a light board I’d opt for EPS as core. If you want a strong board, epoxy and carbon/kevlar is your friend. I went the eps/epoxy route but only because I couldn’t get a polyurethane blank at a resonable cost. regards, Håvard

how funny. i’m doing a carbon fiber/ kevlar epoxy board right now…just glassed it!!..on a clark blank 95s… bitch to cut that stuff,even with the special shears…looks like the B-2 gold/black…with gold glitter.just experimenting with the expensive stuff …my last one i did was an epoxy lamination coat with a poly hot coat then gloss…regular 4oz…(thought that might keep it from yellowing)…well it did’nt…but the manufacturer said i could’nt use poly on top of the epoxy…worked ok even buffed out nice…the board worked well…but had a different flex to it…much stiffer…i’ll try more composites as they become available…BJ in SD