zarb said...Mark _australia said...
blah blah crap on a bit..
Hey Mark can you break down a few of the constructions for me? I have been surfing my entire life on PU boards so I don't really know much about the other methods. Like the basic epoxy vs sandwich construction.
Old school surfboard - polyurethane foam ("Clark" foam) with fibreglass and polyester resin.
New school epoxy surf - polystyrene core about H grade (20-30kg/m3 ish??? can't recall) with glass and epoxy resin. May have carbon / dyneema etc patches but you can't see cos it is painted. Probably no stringers like conventional surfboards. Often they are popouts so the thickness and quality of glass is really hard to ascertain. Most will be similar strength to the former, quality ones a little stronger than old-school construction. But you dunno what you are getting it maybe moulded with t he polystyrene balls blown in then fused together which is waaay weaker than a proper styro blank shaped then laminated.
Stronger - new school construction with addition of a wood layer. Best is pine, most will be balsa whish is marginally weaker than pine and soaks up more resin.
Addition of carbon fibre patches under feet etc is even better.
Best - polystyrene core with a layer of glass, then divinycell (PVC foam) vacuum bagged on, then more glass. Very hard to do. This is how windsurf boards are built and why they are $2000 - $3000. Very labour intensive, especially in getting the very rigid foam to bend around the styro core. Pic coming...
Basically a sandwich will always be stronger than the sum of the parts. Like laminated wood, or the cardboard with the zigzag layer in the middle. Much more rigid.
I found it impossible to find a pic of north's construction - even a 'claimed' construction. However given kiter2007's damage i would suggest it is basically a popout surfboard like NSP, with addition of one extra layer - maybe wood - to make i marginally stronger than a surfboard. Not worth double the price methinks.
But then you blokes won't want to pay $1500 for a board surely...

above is styro, 2 layers of 3mm divinycell and glass in a 2004 model WS board.