Poly Coat over Epoxy Coat??

Aloha, I am thinking about ordering my 2nd Epoxy board I like the lightness and strength . But have a Question… I think the Glasser (Greg knows him) used poly resin after the lam coat … I don’t know that much about it but think he told me he was gonna do that and most of his boards are done that way . It’s a great board very light but I just wonder if he had used Epoxy for the whole thing if it would have been even lighter … And stronger?? I think it’s a cost thing but wonder if it would be a good idea to ask for all Epoxy and pay the extra for it? Thanks for any input I can get on this .

I guess that the best person to answer this is Greg Loher …

I’ve only recently started to shape boards. I was advised not to cover an epoxy laminate layer with polyester resin hot coat. The reason give was that the bond formed between an epoxy & poly resin is not as stron as a poly - poly bond or an epoxy -epoxy bond. But like I say I’m relativly new to this and this is just the advice I was given by a brazialina friend of mine who has shaped a few boards in his time.

Brian is exactly right. An epoxy hot coat will be stronger and the bond between it and the laminate will be better. I have done poly hot coats and it does work but epoxy to epoxy is the better way to go.

Do you still use standard S.A. for epoxy hotcoats, or an epoxy version of S.A., or nothing at all?

Thanks for the input. So it would be better as far as adhesion? of the hot coat and stronger . But how much weight would it save in your estimate on lets say a 9ft. longboard? Would it be very much ? Thanks Again …

Rook-- I’ve used some Resin Research epoxy product. The Additive F is the key to controlling amine blush with epoxy laminations and hotcoats. I use it in all laminations as a flow enhancer. All of my hotcoats/sanded glosscoats get a shot of Add.F to insure a good bond between different steps. You really don’t have to go through the tedious sanding and alcohol wipedown/ prep between lam and hotcoat steps. I’ve not used the new fast curing hardener but it would seem that this would make the whole epoxy process similar in timelines to that of using polyester resins. I believe there are some options of mixing the slow cure and fast cure hardeners to customize your kick times to suit your project. As far as sanding agents in epoxies, there are none to add. Epoxy sands very easily, probably because it cures much harder and faster than polyester resins. I find myself uisng fewer sheets of sandpaper, no gum up like polyester. Additive F helps with flow, bonding and sanding and can be considered a multipurpose agent. Hope this helps. Tom S.

Be carefull,I some one tells you poly will bond to epoxy, be suspicious. In the boatbuilding industry it is a cardinal sin to laminate poly over epoxy.You will get an initial phisical bond but no chemical bond.It will eventually delaminate. Gregs resin must be different to other epoxies if he has’nt had any problems. If you are going to start with epoxy, finish with epoxy. I dont see any point in using the two together.You are better off spending the extra money and being able to sleep at night knowing you brand new board is’nt going to fall apart half way through your next surf.David.