i live in new jersey and am looking to buy a single fin shortboard (similar to moss spacecake or old bing good karma egg style) probably around 6’6" since im a pretty big guy (6’2" 195 lbs). The local shaper around me, tom eadon for cosmic bull surfboards, is currently only using EPS/ epoxy and will resume PU and poly resin in march, but im eager to get a custom order in. So heres my question: Will buying the board in EPS make any difference to the glide of the boards, i.e. from the displacement difference due to the reduced weight and flex etc? Also, i’ve heard a lot about how EPS tends to soak up water like a sponge. I’ve never done any repairs with epoxy and feel like I’d be constantly worrying about the board being ruined from a small crack. Would it be smart to get a PU blank glassed with epoxy for the added strength, and would anyone recommend that over epoxy/EPS? Also if anyone knows any other reputable shapers in the greater NJ area with whom theyve had good single fin experience please tell me. Thanks a lot!
It all depends on the weight of the EPS. i.e. The lighter weight the EPS more it will differ form the Clark stnadard in feel. Similar weights will feel much the same.
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Will buying the board in EPS make any difference to the glide of the boards, i.e. from the displacement difference due to the reduced weight and flex etc?
glide, no not really; at the same volume it will feel a little corky because it will flaot back to the surface faster (i.e. duck diving and setting a rail). The solution is go about 1/4" thinner than you might otherwise.
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Also, i've heard a lot about how EPS tends to soak up water like a sponge.
Not true, if your EPS is similar wieght to the Clark like blank then they will tend to suck water in a similar fashion. The biggest difference is once you have water in the board. Water will break down and discolor the PU blank rather quickly but have little effect other than adding weight to the EPS blank. Further the PU blank will hold the water, while you can get the water out of the EPS blank.
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I've never done any repairs with epoxy and feel like I'd be constantly worrying about the board being ruined from a small crack.
good epoxy is very easy to work with, further the eps/epoxy board will be a little more resistant to needing repairs.
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Would it be smart to get a PU blank glassed with epoxy for the added strength, and would anyone recommend that over epoxy/EPS?
OK I’m an epoxy pusher, all my PU boards have been Resin Research epoxy. Env friendly, easy to work with, stronger… why would you use anything else.
I’d find a shaper with eps/epoxy experience (not just someone who is doing it until they can get more PU) and go that route. It the future, I believe.
4est advise about finding a builder that uses those materials regularly is good. I think you can build your own using epoxy/eps. Epoxy resin is not much different than polyester resin using traditional building techniques. I’ve used epoxy on Clark foam and completed a board using it on eps. The eps board is within the weight range of my polyester/urethane boards of the same size. Have not ridden it yet ,but there is no reason to assume is will not have the drive of more traditional materials. I did build it thinnier(1/4 inch) thinner than urethane boards. The board you mentioned are simple designs I believe and I think you can build your own. Give it a try. mike
hi coaster…i ride single fins…the best ones are 2000’s design s, not a 60’s or 70’s version…the best single fins today in USA would have to be close to what they are making with thrusters…there are special design aspects that do suit a single… “enjoy being different”…you can change your fin and fin sizes, making one board into many…
i did not know those facts about the eps–> that a similar density board to CLark will absorb water similarly AND that its less damaging to the EPS, i was under the assumption that once water got into the EPS you were toast. So are you saying basically that its easy to fix the EPS even if water gets in just by lettin it dry out?
So are you saying basically that its easy to fix the EPS even if water gets in just by lettin it dry out?
yes you can drain it out. there was a recent thread talking about drilling a whole into the board on the opposite end to the ding or vent plug to allow air flow through the board and then letting the water drain out. Some talk even about low preasure blow out. Then just fill the whole afterwards. I’d think once you’ve put the whole in just add a 2nd vent plug.
From my experience with EPS/Epoxy windsurfers I can say that the water issue is a no brainer. Windsurfboards get deep dings all the time and we just wrap a black garbagebag around them and leave’em in the sun for an hour or two, you can actually see the water bubbling out of the board. Test with an intimate mouth-to-ding suction moment to see if you suck air or water or , in the best case, nothing at all. When dry, let the board cool off properly in the shade and repair with fiber and epoxy, cure, sand, buff/paint and voila…
As to making surfboards, I am interested to know more about adjusting existing shapes to EPS/Epoxy, I know it’s lighter and stiffer but what does that mean for my thickness, rails and rockerlines… I am currently drawing out some longboard templates that I want to make as my first EPS surfboards and I am curious as to the results, anyone here made any decent logs with EPS recently?
I am making an 8ft “longboard” (8ft…cause it fits in the car…) and have only really shaped EPS …done a couple of polys. EPS does not suck water…it is a closed cell foam…take a chunk…put it in a 5gal bucket filled with water…put a brick on it…check in a day or two…test it for yourself, good 2lb foam does not soak up water. The only water that gets in soaks around the exposed beads…thats it…almost no real penetration,closed cell. Anyway…I have just(like others) just taken the thickness down a 1/8-1/4" …thats it, rocker and rails the same. EPS is just foam…a better foam, but just foam. My 8ft board has a 6+6+4 deck and a 6+4 oz bottom…weighs just under 8lbs…box installed, no fin, not hot coated…should be around 9lbs done. Have fun…
I’ve made quite a few EPS/epoxy longboards. Some sandwiches, some just glassed.
You think through the design changes in a specific order: First consideration is getting it to flex. To do that, you need to thin the overall thickness flow. A good starting point is go 1/4" thinner but I’ve gone up to 1/2" thinner on boards with multiple/composite stringers.
Next, you need to get back some volume so it glides & paddles like you’re used to. For every 1/8" you take out in thickness, add 1/4" in width to nose, center, and tail off your poly templates. Its probably an oversimplified formula, but its working so far. (I wouldn’t presume that the same could be applied to EPS shortboards, fish, etc. - I just don’t know the shapes well enough to say.) So If you’ve gone from 3.25 to 3" in thickness, take your 18-22-14.5 longboard to 18.5-22.5-15 and it will work fine.
Thirdly, figure out what else you have to do with that shape. The materials are lighter, so more responsive, so getting it going rail to rail isn’t a problem with a little extra width, especially for a bigger rider. A bit of vee through the fin would help a lighter surfer, a kid, a woman, someone with small feet, etc.
I generally do away with nose concaves, as the lighter boards ride high in the water just fine. A little belly under the nose helps smooth them out through chop or wind.
Finish it off with a nice wide pivot-style fin to calm it down. Once you get used to the way it reacts, switch to a flex fin and you’ll really have fun matching the flex of the board to the flex of the fin on big deep bottom turns
