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AndyrooMac said..
Question,
I'm strictly a Poly/PU guy when it comes to materials, I like the feel and flex pattern and prefer heavier boards as they maintain better momentum and glide for me...
But then you can glass Epoxy/EPS heavier from what I have heard and it has better lamination and toughness for durability...
And you can Poly glass an EPS blank which is stiffer/more durable and apparently more eco...
So, what are you're preferences and ideals?
Am I right in my above assumptions?
Let me know you're thoughts... cheers
You can't poly glass an EPS blank. The styrene monomer in the resin eats the foam.
Straight up the whole epoxy board thing is hugely misunderstood. All this bull**** about Epoxy having more float etc etc...
As far as the finished product is concerned you have total volume and the complete weight. That determines the buoyancy (float) regardless of materials. An EPS blank glassed to the same finished board weight as a PU blank will have the same 'float'. There might be very slight differences in weight distribution but really if you think you can pick it you'd better watch the way you wax up because it might mess up the feel of the board with the extra weight in unusual places.
Flex pattern - Maybe. I'm calling BS on this too but not so emphatically. If someone wants to open the discussion I'm more than game. Epoxy as a resin is both more flexible and less brittle than polyester, However the resulting laminate has greater tensile strength which is the thing that contributes most to stiffness of the board as a whole. So yes, the PU/Poly board will be a little bit more flexible, the actual amount of flex though is so minimal I just can't buy into it being a factor. People sometimes cut through stringers to install fin boxes, sometimes they don't - this will have a far greater impact on tail flex than Poly vs Epoxy. Likewise a relatively small change in the thickness of the board will impact flex way way more than the resin used.
I've been using epoxy for my own boards since the late 1980's, for ages and ages with a standard Polyurethane surfboard blank, more recently with EPS. When I use EPS I double glass - 2 x 6oz bottom, 2 x 6oz + deck patch top. All layers except the patch wrapped around the rail, so that's 4 layers of 6oz on the rails. I use a double stringer and fit the finbox in between them so as not to cut the stringers. The boards have a weight comparable to a typical Poly/PU board. They are seriously strong and durable. I have NEVER broken a board. (Edit - not true, I broke an Epoxy/EPS windsurfer once but I fell on it from a
great height and it was built superlight.)
An EPS blank has a kind of springback resilience that matches well with Epoxy resin's greater flexibility. A PU blank doesn't really springback and matches well with Polyester resin's local resistance to denting. Both are good matches.
PU foam with Epoxy does work fine and is strong but is slightly more prone to deck dents due to the mismatch between the local flexibility of the epoxy layup and the non springback of the PU foam.
PU foam doesn't absorb water in any significant quantity if in good condition and a ding requires a bit of tape over it and a repair at some stage, no big rush.
EPS foam takes water on in the airspace between it's cells like a thirsty man with a straw, and a ding means getting the thing out of the water immediately and fixing it properly before getting it wet again.
You can leave a PU foam board in the sun or a hot car and it will be ok.
EPS foam allows migration of the air contained within it and as such there is a pressure build up inside the board when it gets hot, left unchecked it is possible (it does happen) to blow the laminate off the foam. I put a vent in mine, problem solved. Just don't forget to do the vent up before jumping in!
Regardless of what they say, Epoxy is not stable in UV, it discolours and degrades. Don't leave a clear (can see the foam) epoxy board stored in bright sunlight. Use a cover, take it out to use and replace it after. Or paint it. (my choice.)
EPS is more eco in production but is still a long way from a fabulous organic biodegradable product, it is recyclable but not currently in Australia.
I think we all have a responsibility to minimise our impact and as far as surfboards are concerned, the most direct way to achieve that is to make them durable. There are plenty of options for making a durable board using any of the commonly used materials.