I’m about to laminate my first board using epoxy. I’ve done about 15 using PE, to varying degrees of success, but this one is a donation build for a local charity and the supplier who donated the resin and glass insisted I use Entropy Super Sap. I’m always up for a challenge, so sure, why not?
I think I’ve got a handle on the lamination and hot coating steps, but I’ve realised that I don’t have a clue when it comes to setting the fins. Is it done the same way as I would with PE resin - i.e. pour resin into routed plug holes, set fins and wait until the resin is hard? Is it that simple?
My main concern, which may be completely unfounded, is that the resin will overheat within the routed cavities.
How does everyone else who uses epoxy resins manage this?
Fill the cavities in stages, but within the chemical bond window, preferably with low humidity and dropping temperatures to keep the foam from blowing bubbles
Some guys use gel style ice packs on the other side of the board to keep the exotherm from going crazy.
I prefer using super slow curing epoxy, but usually need 2 fill stages anyway as it soaks in and goes below the level of the tape dam and hull. I don’t use pigment, no comment on that aspect.
Make sure the FCS plugs have a column of resin reaching the deck, and you might want to throw an oval patch or two over them if your feet tend to mangle that area of the deck where the column rings meet the deck.
Do You have milled fiberglass powder?
I never had any issues with FCS plugs tearing out or breaking when installed properly with that resin column with milled fibers, reaching the deck in a full ring.
For the sake of full disclosure, I’m going to be using epoxy resin on PU foam, so I don’t think there’ll be as much of an issue with the foam off-gassing.
Or will there? I don’t know, I’m a total newby when it comes to epoxy.
There are combatability issues between the resins. But,if you set your box with the poly resin, let it cure, sand your box and the area around the box, then use the epoxy resin to cap the boxes with fiberglass the two resins will not be interacting in any way. I never use epoxy to install boxes in urethane foam and most of my boards are glassed with epoxy resin. If I didn’t have any poly resin laying around I would use the epoxy resin and do it in a couple of steps with ice bags as suggested above. Epoxy get very hot when it is allowed to pool. Mike
What you’re saying is making a lot of sense to me Rooster, I think I’m going to go with the poly resin for the fin box/plugs and save the epoxy for the lam and hot coating as planned. Thanks for the help.
At least a decade ago, I installed the old FCS plugs in a poly blank using epoxy. I have never seen an exotherm reaction like the one I had. Looked like the reaction that occurs when gorrila glue starts going off after it gets wet. I was able to yank the plugs out and clean them right away. Once the resin cured I had to re-drill the holes and I used epoxy resin to install the plugs. I had made at about 20 EPS/epoxy boards by the time this happened, so I was used to using epoxy, but not with poly blanks.
The board was laminated with epoxy, but I made it as a single fin and installed the side bites later.
The ‘H’ column of.PE resin surrounding fc1 plugs that is supposed to reach the deck lam., might not bond very well to the epoxy lam on the deck, as poly in general does not bond all that great to epoxy. Perhaps not a factor.in this situation.