Shaping an EPS Surfboard

I have been shaping boards for a little over a year at this point and had never attempted shaping an EPS board or glassing a board with epoxy resin. Never being one to back down from a challenge, I decided it was time to give it a shot. A huge thanks to Total Boat for supplying the resin for this build. It was a great learning experience and very different from shaping and glassing a traditional PU board. If you’re taking on an EPS board here are a few things to keep in mind. 

Shaping

EPS foam is just a type of styrofoam, so it's made up of a bunch of small ‘air beads’. This is great because it helps with flotation, but sure is a pain to shape. As you sand it, more and more bubbles just open up so the blank is never perfectly smooth. To counteract this, many shapers apply spackle to fill all the voids and produce a nice finish to the blank. I opted not to do this and later came to regret it. 

Adding to the issue was the fact that I couldn't use my modified electric planer. It needed further modifications or I would run the risk of having the foam beads melt on the motor and cause it to overheat. This meant that I had to hand shape the whole board. I did find that I could use my variable speed sander to speed up the process but it was still slow going. 

Glassing

The glassing process was not too different from a PU board with PE resin. I used the Total Boat High Performance Epoxy Resin with their Medium Hardener. The products worked great and gave me nearly unlimited time to saturate all the fiberglass. Total Boat also provided me with some tints which looked great and diffused into the resin super easily. The only downside to this epoxy was that it takes 3 hours to lose its tackiness, so once you laminate the board, it needs to sit for at least 3 hours before trimming the cutlaps. 

In doing research on glassing with epoxy before this build, I saw a lot of complaints about fisheyes and holes in the resin when applying the hot coat. I was really worried about this but had no issues with it and took no extra precautions to prevent it. 

Fin Boxes

Installing fin boxes was my last hiccup with this board. Another issue that EPS boards have is off gassing. As the board gets warmer, air trapped within the foam expands and wants to escape. When glassing, this causes air bubbles to appear between the fiberglass and foam. To prevent this from becoming an issue, you are supposed to glass EPS boards in dropping temperatures. I took this into account when laminating, but didnt think about it when installing the fin boxes. After I set the epoxy and covered the boxes with fiberglass, bubbles started popping up everywhere because of the off gassing.  I eventually had to slice a bunch of small holes in the glass to let the air out. I then had to come back later to fill them with more resin. 

The Result

After all the mistakes and steep learning curve, I had a finished board. I have been riding it for a little while and it's holding up great. The Total Boat epoxy is super resistant to pressure dings and is holding its color great. I am learning that I prefer working with and riding PU boards over EPS, but both are great options and have their strengths. 

Stay Stoked!