Epoxy on PU

[Oldie]

Hi all,

There are lots of discussions on the different benefits of Epoxy or Polyester glassed boards, but there always seems to be the assumption that Epoxy means EPS/XPS blanks. (I am not considering popouts/surftechs etc here).

However, it appears to me that, appart from colour work, Epoxy is a much better resin than Polyester, so building a longboard on PU with Epoxy resin could use the benefits of Epoxy while keeping the weight and flex of PU and reduces the risk of water damage. But this does appear to to be very rarely used or offered.

Why is that such a rare combination?

[oldmansurfer]

I am not sure why that is but there is a variety of materials to use as blanks and even just within EPS foam there are variations of density and other parameters. In additon there is extruded EPS foam called XTR or XPS which doesn't absorb water. EPS foam can be much lighter than PU so the EPS/epoxy board allows the lightest weight for the strength. In my imagination I would want a board that would have been lighter but was made more sturdy by using more glass and resin. Pu foam will absorb a little water and it will rot if not dried and protected soon enough. I think XPS is the way to go but it is way more expensive but maybe there will be something in the future which is light strong and better for the environment? I think modern surfers especially the top end look at surfboards as disposable. You use them and throw them away when you are done. Maybe if some board creating strategy can make that attitude go away then it will filter down to all the wanabes and that would have a major impact on the environment.

[billie_morini]

oldie, i have 9 foot longboards made with polyester resin, as well as, epoxy. From these boards, it is obvious the poly flexes nicely and epoxy is stiff. When I ride the poly boards, it feels like i am in or part of the wave. When i ride the epoxy boards, it feels like i am a cork on top of the wave. i prefer the poly.

[waikikikichan]

Billie, are your Epoxy boards "hand shaped" EPS blanks with wood stringer then glassed with Epoxy resin or molded Epoxy boards like a Surftech that have no stringer. Most of the EPS/Epoxy "normal" construction boards I have ridden had more flex than the PU/Poly boards. The molded Epoxy boards I ride are stiffer than my PU boards.

[Oldie]

Billie, are your Epoxy boards "hand shaped" EPS blanks with wood stringer then glassed with Epoxy resin or molded Epoxy boards like a Surftech that have no stringer. Most of the EPS/Epoxy "normal" construction boards I have ridden had more flex than the PU/Poly boards. The molded Epoxy boards I ride are stiffer than my PU boards.

That would be my expectation, too as Epxoy as such is a bit more flexible than polyester.

But I am more wondering about the scarcity of the combination of Epoxy & PU blanks. Searched a little and in Swaylocks there are remarks the people see more delamination issues than ususal?

[oldmansurfer]

There is so much that goes unnoticed in surfboard design. If you haven't ever owned a pu/polyester resin board you might not know they get leaks which caused the foam to rot and delaminate if it isn't rapidly dried and patched. I have not had epoxy resin board till this time around surfing and that is all I have had recently. My 2 favorite boards are epoxy/eps . The 8 foot board has no stringer. The 7'6" board has a bamboo stringer that on runs along the top of the board (not placed in the middle to allow a 5 fin set) Both boards feel like they flex. If they get damage water soaks in but it comes right back out and no delamination occurs (so far). I used to cut open the fiberglass to dry out the foam and hopefully avoid delamination when I had pu/polyester boards but with epoxy I place the damage at the lowest point and allow gravity to take it back out along with heat. I may put it in the sun for a while with the damage at the lowest point to let the heat drive out the moisture. There has been no discoloration or delamination (so far)

[billie_morini]

Billie, are your Epoxy boards "hand shaped" EPS blanks with wood stringer then glassed with Epoxy resin or molded Epoxy boards like a Surftech that have no stringer. Most of the EPS/Epoxy "normal" construction boards I have ridden had more flex than the PU/Poly boards. The molded Epoxy boards I ride are stiffer than my PU boards.

Sorry, Waiki. Been working a lot lately. The primary epoxy board I use occasionally is a red, pop out, that has a stringer. Yes, the color is important. As a teenager, I painted my racing motorcycles red because red is faster. I like my hand shaped Don Mel poly long board more than anything! It flexes just right.

[waikikikichan]

I like my hand shaped Don Mel poly long board more than anything! It flexes just right.

Any relations to WSL commentator/big wave stand out Peter Mel ?

[billie_morini]

I like my hand shaped Don Mel poly long board more than anything! It flexes just right.

Any relations to WSL commentator/big wave stand out Peter Mel ?

Yes, Don Mel is Peter Mel's father. Don harkens back to the early days and is who is who among the historic icons. Peter grew up in all of that. It's why he is tops amonv today's who is who.

[billie_morini]

Thank you, Big H.