Wanted to share this as a guide to anyone thinking of doing a board out of construction grade xps foam. I did this project simply to see if I could; It is far far easier to make a board from an actual blank and if you’re just starting out please reconsider just getting a proper pu or eps blank. I have a great local supplier of blanks and resin (green room epoxy made right down the road) so this was only done out of wanting to experiment and because next to surfing board building is one of my favorite activities.
case 3 (or 4 really) of building a board from trash: 5’10"x19 1/2" x 2 3/8"
The board still needs to be surfed but feels identical to a pu board underarm. Not a fan of eps so when I heard xps felt closer to pu I was interested.
step one was to collect some foam from some construction dumpsters. I live about a mile from a massive housing development going up along the cape fear river so foam is plentiful right now. Unfortunately that means they’re clear cutting a ton of wooded area to make these houses. The pic is my foam collection after a couple trips. The good 3" blue came from another area but still a new construction house in an area that floods a bit with certain tide cycles. The house doesn’t even have siding on it and they’ve already tore out all the first floor fiberglass insulation to replace with the Dow XPS. I’ll gladly take your offcuts since you didn’t do your research on where you were building
Step 2 was to cut and glue up rocker slices. Blendingcurves.com has some great rocker templates. I did these 6’3"x2.75" with 5" nose rocker and 2.25" rocker knowing that I’d be cutting from the center. I wasn’t too concerned with cutting straight since I knew my finished board was going to be significantly thinner than the blank. Glue used was standard foaming gorilla glue
Here’s my finished “blank” once I got the thickness all sorted out with the surform and planer. This thing flexed a TON while shaping and there were some weird low and high spots due to my faulty (aka lazy) glue up using the bricks as weight. I think once the gorilla glue started to foam it made the layers shift some. But in the end I got a decent enough blank to work with.
the rest of the build will be updated this afternoon
Cut outline and first attempt at a shape. Glue lines really made things more difficult, especially on the rails. Might not have been as big of a deal if all the rocker slices were 3" wide. It would have changed the positioning of the glue lines so there would be less on the rail I think.
Like I said I had a ton of trouble foiling the rails because of the soft foam coupled with the rock hard glue lines. At one point my rails in the center of the board were so soft that I thought the project would be a waste of time. They were like 50/50 fun board rails when when I wanted 80/20 and thinned out. I was seriously ready to put the board back in the dumpster where it came from
But then I thought about it for a night and realized this isn’t my first rodeo with hacking up a shaped board (see My original trash board thread). I cut off a few inches on each side and glued up some 2" thick slices of pu in their place and reshaped. They still came out funky towards the nose but it was nothing that a ton of q cell couldn’t fix after I lammed the bottom. Doing the q cell after the bottom lam and before the top lam gave me a little rigidity and the glass on the rail prevented me from sanding into the foam.
Decided to go clear on the glass job to show the beauty of the imperfections and because I honestly like the colors. Did 6/6+6 with a 6oz strip down the stringer. I want to add that i am very aware of the issues surrounding xps and heat. I honestly thought any board with any construction would delam if it got too hot so I’ve always taken really good care of not letting them overheat. I did leave the surface rough for max adhesion
For fins I usually do futures but since I doubt this will be going on any trips I went with glass ons. A few years back I found a guy on eBay selling fins he had stripped off of old boards that he was selling for $5 a set. These are leftover from them. I went with a hair smaller center fin to keep things loose.
one last thing, whenever I make a board I sneak some of my dogs’ hairs in for good luck. Sometimes it’s under a future box or mixed in with the resin for the leash cup. This time they were sprinkled in to the hot coat under where the pad goes
