next »

[Fernando Mattos]

Hi dudes,

my english is not so good, so sorry in advance for that.

I've just build my 1th HWS, a 6'4" fish, that made me a bit disapointed for it's 24 lbs!
So trying to find a way to make the next one lighter, I found this great forum.

An idea that has ocuppied my mind is if anyone has made a hollow hi-density pvc foam surfboard.

I've seen in this forum HWS, solid EPS foam boards, and others blank materials, but haven't seen a hollow surfboard, using, instead of wood,  pvc-foam sheet glassed after molded to the inner structure and rails shaped. And using for the inner structure (the fish bonnes) maybe plywood or some solid lightweight wood. Guess that will have to glass the pvc sheet both sides, before gluing to the structure, but already with the rocker and deck shape.

My marine building supplier has pvc foam of a variety of thickness, and lot of densities (from H35 to H250). I'm gonna ask some foam samples for helping me to choose which density and which thickness, but I'd love to receive from you guys some ideas to help me!

THanks and good waves,

Fernando Mattos, in Rio de Janeiro, Brazil.

[Kit Sidwell]

A few people here have used PVC quite a bit, it can produce a really good board!
It is the way to build very light boards, and the have less problems if you get water inside them.
Most of the boards built with PVC are  not completely hollow, they use EPS cores.
I suppose that you could use it in an HWS style construction....

I've used Airex, and divinycell for various things, and corecell too (not a PVC).
I'd recommend Airex H80, 3mm thickness.
Start by glassing it with 1 layer of 6oz cloth, that will be nice and strong. 4oz cloth is possible too.
H60 is good too, but I can only get it in 5mm

PVC foams are heat-formable, so you can bend thicker pieces around the rails of the board.
I'm interested to see what you do!

Kit

[Fernando Mattos]

Hey Kit,

thaks for the feedback! Gonna start my research by your sugestion, with H80 or maybe a bit higher, with 4oz cloth (the one I have available in home).
I read, guess in Tree to Sea forum, that if, for saving wheight, we have to choose betwen lighter planks or lighter fiberglass, we should save on the glass, as the heavier plank guives more strengh than the heavier glass. But that was for wood, not sure if will work with foam. I'm starting to consider some lab (means garage) tests with glassed foam samples. Let's wait my suplier answer about the samples.

I'll post as the work advance.

Iemanjá bless you

[Fernando Mattos]

Ok, guys, here's the plan:

8mm wooden structure (skeleton), full of holes for lightinning
10mm divinycell H80
laminating 1x4oz inside and 2x4oz outside
a tape of 4oz fiberglass laminated inside where the wood lays on the foam

Saying now, seems a bit oversized, but the foam is already bought (no cheap at all! about USD140,00), and I prefer to start with a heavy board and improve the next ones than start with a broken board and get discouraged with the metod.

By my calculations, its gonna have 3,5kg (7,7lb). Is that acceptable? My actual common board have 3,2kg...

Already started to draw in the foam plank. As I have it cut I'll post some fotos of the process.

See you...