by Jimi » Tue Dec 05, 2006 12:14 pm
Traditional boards are made from polyurethane foam (it's an isocyanate curing foam containing Toluene among other things).
It was invented in the 60s by Clark (of clark blanks) and Hobie (same name as the surf catamarans). Shortly after it's development, it replaced Balsa as the favoured material for shaping.
There are new types of foam out there, but if you want to buy a blank, you're looking for closed cell polyurethane foam.
Typically you'd use polyester resin and fibreglass woven roving to coat your blank, to give a "typical" surfboard.
If you are in an area where exotic materials are available, you can use epoxy resin instead of polyester, to give a stronger, stiffer and more durable shell, while keeping the weight the same as in a polyester lay up.
Finally, in my pipedreams, i'd love to make a composite board, using a normal blank, but instead of using fibreglass woven roving, I'd try a shell of carbon fibre (the workmanship is almost identical for carbon fibre as for fibreglass) using epoxy resin.