…Im wondering myself why one of the many PU factories in USA not take the market?
…most are huge…
…yes, the formula is a bit different, but they have engineers…
…may be is a possibility for the PU boards…
Why not? Probably BECAUSE they are huge. And most likely because what they produce (mainly insulation foam) is as far from a real surfboard blank as can be. Those huge plants have huge belt conveyors upon which the foam is continuously poured, expanded (FREE EXPANSION, which is quite different from expanding inside a mold), then cut into blocks of various dimensions. My very first boards were shaped out of such blocks, the only kind of polyurethane foam available in France to backyarders 35 years ago. Just like polystyrene blocks, you have to start with a really thick block so that you can shape some rocker into it: lots of work, lots of dust, lots of lost material (which, incidentally, is not recyclable whereas polystyrene is). And since this foam expands freely, the density is quite the same everywhere. If you want a light board, you choose a low density but then it has no compression strength. If you want a board with some strength that won’t delaminate as soon as you stand on it, then you choose a high density but your board is going to be heavy.
What Clark did was to formulate his foam in such a way as to obtain high density on the outside of the blanks and low density inside. With a possible choice between 4 “current” densities and even more on special orders. With close tolerance molds to help keep the strength where needed.
I’ve also been told that the way you pour the foam into the mold is critical. Only trained employees can do that just like it must be done.
In short, making CLARK FOAM blanks is not something anybody can do tomorrow, far from it…