Just don’t use elmer’s glue, if you ask me. It only dried to about 2 inches from edge, everything closer to the center stayed liquid untill I shaped close to it and it got in contact with air. The EPS just doesn’t soak glue like a wood would. It worked really great for attaching the two sides to my cedar stringer, but not for laying up the sheets of 1" eps itself. When I did shape close enough to it for it to dry completely, it made a crust that created bumps on my rocker curve as well as my rails. I think it is a good idea, but only if you go with a more workable glue. Maybe a contact cement, if it doesn’t melt eps? Also, with the elmers, my layers delamed in places during shaping, and are only held together by the glass job now.
Going to post up a picture of the finished product as soon as I get it sanded out.
I have made 3 boards to date from eps and 1 from expanded.
Glue was a big problem to start. Get the gorilla glue. After the first I realized its better for me to cut the rough shape and glue approx 1 in. in so you don’t run into the glue wile shapeing. I used bricks to laminate the 3/4in. sheets I was using and tape and weights to hold it together. get the bottom right before gluing. I used 6oz.s cloth and epoxy. found the s cloth hard to get bubbles out. Not sure if it was the cloth or air from blank,I would get them out and they would re-appear. First board started to de-lam on top so I added dead heads through blank to hold together. the next I cut diagonal slices for grip,it also bubbled up. The next I used the expanded and found it very soft even after 2 layers of s and 1 of reg. You will have a extremly light board,so with the epanded I used 3/4 cedar for stringer with no problems. Good luck, do your home work on the de-lam problems.And let me know if you solve the problem.
I have made 2 boards out of EPS now. I used Elmers on both and didn’t have any of these problems. I rolled on the glue with a 3" high-density foam paint roller and let the glue set up for about 10 minutes before putting the pieces together. I then piled all kinds of heavy stuff on the blank and let it sit for 24 hours. If any of the glue would have been still wet, I would have discovered it when I cut in the stringers, which I did after gluing up the blank…there was no wet glue inside. Maybe the glue needs exposure to air for a few minutes to start the hardening process and after that it keeps going.
The glue edge around the rails was a little harder to shape than the rest, but I shape with a grinder & sanding pad and didn’t have any problems. I also didn’t get any blank delams, even where the rocker shaping exposes the lower piece of foam at the seam where its paper thin.
If you want to go stringerless, I’d do what RFD suggested. He thought - and I agree - that a piece of 6" wide 6 oz cloth laid flat in between your two pieces of foam and glued in with epoxy resin would make a great blank with pre-made rocker. You would have to choose a pretty natural curve, because you’d have to glue up the blank on a couple of sawhorses with weight in the middle. And even then, I’m not sure you’d get really good adhesion without some kind of weight (clamping) everywhere else. I think shaping down to a pre-shaped stringer gives you exactly the rocker you want and you’re not fighting any material ‘memory’.
My mistake, accually 2 boards made from extruded 1 from expanded. But I believe 4est is asking about the pink stuff which is extruded. In which case carefull for delam. No probs so far with the expanded foam even though I was scared because of the softness. The stringer was put into it to help against possible delam. the other 2 do not have stringers.
The 2nd board is the best I have made,wile polishing it was knocked to the concrete. Thats when I relized just how good the epoxy was, just a scratch.
It seems that many that want to do an EPS blank are afraid of a hotwire. If done properly I could only imagine that a hotwire would be the best way to go.
It’s been awhile but my good surfing buddy had a neighbor that did model airplane wings out of EPS using a hotwire and these were like 5’ to 8’ wings and a fairly complex foil doing both sides. But he always had a friend that was skilled to help him pull the hotwire through the foam. The templates they used were marked in inches and they had a system of calling out the inches as they made the cut so they were the same place on the template. And it seemed that it took no time at all really.
The end result was almost perfect cut with not really any of the noticeable wobble in the cut that I saw of Benny’s posted recently. These foils where much more complex than a long gentle rocker of a surfboard. Now I wish I’d paid a bit more attention to what this guy was doing because I’d like to hotwire some blanks from a larger piece of foam and this guy has since moved away. His hotwire was home made and he appeared to be using a battery charger and controlled it with a light dimmer switch and he wired in a amp meter to know his temperature of the wire by how many amps were going to the battery charger.
Also the cost of this foam is very inexpensive as everyone know by the Lowes prices. If you bought a larger block of foam I could only imagine that the end cost of multiple blanks would be even cheaper, that is if you could pick up the foam yourself and avoid any type of shipping cost.
Anyone know where to get a large block of the EDRO EPS foam in Southern California. Has anyone here bought a blocks of the EDRO EPS from Insulfoam in So. Cal.?
lowes is being gay. It keeps saying that either tehy don’t sell to my location, so please enter a new one, and it won’t just let me browse products. If it doesen’t say that it says they have discontinued the line of product. Does any one know where to get eps in the san antonio area?
yes and no; at least for me it is not really a fear but more of I want to try EPS before I invest in the time/equip/space to hotwire. I plan to build a simple rocker table and glue in the rocker. Most of my boards will be cruisers where I actually want the weight so I am not sure I’ll continue with EPS but we’ll see. Plan to do at least a couple of EPS though (son and wifes board for weight concerns).
yea, I have tried HD, usally about the same results. I found a new foam there recentrly, and was trying to decide if it was polyurethane, and was going to like test a peice to see if it was but never got around to it. but it got me thinking, what if blanks were molded in layers? So you don’t have the crust then dust results?