Hey everyone, im new to this site and currently experimenting making boards out of EPS boards. I’ve started this thread and will keep updating for you guys to see and help me out in the process of shaping my first board
Anyways i started off with a 4’x8’ board at 4 inches thick. i dunno if im on the right path here but anyways heres what ive done so far (attached).
Ive cut out the template in half hoping to put a 4 inch stringer throught the middle of the thing and then mow down to the planned rocker… but just now i realized i may have dug myself into a hole i cant get out off hahaha been reading some posts on here about them bending the foam and then putting the stringer in the middle, my fear if i bend it (4 inches thick board) it might snap since its a whole piece board.
What do you guys think? anyone care to help me out here? thanks guys!
You’ve already split the blank down the middle? Create the stringer with the finished rocker and thickness you plan to achieve. Trace your stringer onto the inner, flat sides of the foam. Then remove most of the foam down to the line, but leave a little extra. Then glue the two halves and the stringer together. Proceed from there. If any situation called for a hotwire setup, this is one.
I see… is this possible using an electric planer? or do you recommend i use the hotwire setup? i had that in mind before actually (mowing the foam and using the stringer as guide) but when i read some of the posts on here and on other sites, they bent their blanks and i started to think i kinda screwed up hahah
I would just plane it if you are strapped on funds? I am, so I have to count my dollars… look into rocker templates, and make one. Then you can make good board’s. I gotta make one myself.but hotwire if it makes a difference … if not, plane it.
Okay, i will try out your tips thanks for the tips!!! ill update you guys next week, unfortunately i only get to work on it during sundays cus i got work.
Cutting out the stringer and seeing if you have enough foam to proceed without bending is the best place to start. If your stringer fits inside your precut foam, awesome. If do not have enough foam, one quick and dirty solution would be to figure out where to cut the foam at the nose (like 2’ in) and bevel to make a joint that allows the thick foam to follow the stringer. You will gain a glue joint, maybe two if you add a piece to maintain length, but you won’t have to scrap your work in progress.
I have made three blanks out of one 4x8’ x 6" thick EPS. Two blanks were full-sized 7’ and 8’, rockers cut before plan shape by hotwire following stringer templates on each side of the blank. The third blank was made by scarfing the offcuts together into a blank for a wakesurf. The wakesurf is a goof-off project, freehand hot wire and lots of planing, and now I need to split the plan shape and add the intended stringer.
Our first attempt at bent layered EPS on a rocker table failed because I picked the wrong glue. Given a choice I’d use thicker foam and hot wire cut the rocker.
I’m not sure? But I don’t think you have to have a stringer w eps? I would see what - Mike Daniel’s has
to say about it. I think he and some folk’s build um on eps without a stringer. It’s up to you on that one. If it doesn’t matter, I suppose I would just build w out stringer.
I would definitely use a rocker template though if you can find one.
I would do the best with what you got, or can swing… if you can.hotwire it, hot wire / plane it, or whatever- I hope you get a good blank to work on. @ $20.00 a blank I might be interested in making one myself! Good luck!
I wish I could help but the op should have asked some of these questions before starting, not after cutting rough outline and splitting the piece of foam. From where you’re at, it’s a different set of problems.
Since foam is split, you’re going to have to glue something in there - and a stringer is best if you’re trying to bend in some rocker. Make it at finish profile like Sammy said, or at least very close, and index to deck side when you glue up (less bending that way). Then you’ll be doing your thickness reduction from the bottom, shaping to the stringer. You could have hotwired away some excess foam, but outline cut has now complicated that. Cutting the rough outline complicates glue-up too, because you don’t have a square piece to clamp to. But unless you had the bar clamps on hand to do a glue-up, you’d probably be doing it with miles of tape anyway. It’s really hard to get even pressure using tape, which you’re fixing to discover.
We can do stringerless because we’re putting on a very high fiber content skin that can’t be duplicated with hand lam techniques, I don’t recommend that others try to duplicate our results unless they’re willing to develop techniques other than a bucket and a squeegee.
I think it’s a waist of time you by crappie foam that s like 1 lb and you tri to bend it into a shape that will bee all twisted and sketchie up. And you did et all four $20 us dollars. So whan you threw away the blank you made and go by a $40 us dollar on1 now you well have spent $60 us dollars for you blank. Not to mentieon you well need to cover it with a lots more firberglass to make it un shetchie. It well nevar be right.
Yes. I failed to mention that. Always easier to clamp work when you have straight, parallel edges. You’d simply assemble the pieces as desired, put a 2x4 along each side, and clamp the hell out of it with some bar clamps. Having the outline already cut makes for tricky clamping procedures. Some guys have been known to use bicycle inner tubes as strap clamps. Like some kind of big old rubber band.
Omegalove, if you can, save the plan shape offcuts and use them as blocking/padding while clamping for reasons mentioned by Mike and Sammy. Your cause is not hopeless.
Shapa-The economics of making a blank…which is more than 20$ after glue and stringer…depends on where you live, what you have for tools and space, and what you hold more dear: time or money. For me, 1500 miles inland (shipping costs more than the blank) in the snow (small heated work space), homemade EPS blanks and epoxy make sense from a cost and working conditions perspective. If I were by the sea in the midst of surf culture, I would think more about buying a polyurethane blank and using polyester resin for costs, excepting that I really like epoxy now…
Omegalove, you will need surfboard (clear uv-stable) epoxy resin for that EPS. I am a big fan of Resin Research. Don’t use stuff meant for industrial purposes. Been there, done that, wrecked the t-shirt…
Sammy, you are a hoopy frood…I hear you loud and clear.
Yeah, I got my eye on a us blanks eps blank for $59.00! It had a stringer fyi. There’s another for ?60 and over size thick…might be good for a big guy psb?
Make a stringer that has the thickness profile set. If your foam is 4 inches thick you should be able to get a decent stringer set in there.
Use the offcuts to help clamp the foam onto the stringer. Use a Polyurethane foaming glue like Gorilla glue or Elmer’s to glue up the blank.
Once the glue is set you can use a surform, planer, cheese grater, or 36 grit sanding block and work the foam down until you get to the stringer.
Make sure you have the blank level when you hack away at the foam. You can start by working along the stringer then matching the sides and keep it flat. If you want to have concaves then preplan that stuff before you hack away because the stringer is pretty close to the final.
If you are using 1lb EPS it will need heavy glassing and it will still probably end up with the stringer sticking up from the foam after a while.
You could also just glue the foam back together to make a stringerless board, but you won’t have an easy guide to cut out the main shape (rocker and profile). A rocker stick will do the trick if you can make one, it’s simple to do.
Then with a stringerless board make your laps wide and double instead of single. Lap the bottom layer about two inches around and the top layer should be about an inch. Do that on both sides and it will be strong as long as you don’t sand through the laps. Do three layers of glass on the deck, or 2 layers of a heavier glass. I’ve done 2 layers of 9 oz glass. Use a slow cure epoxy resin to get a lot of time to do the lamination.
It’s a lot of work when using non standard materials. The money you save on the blank can cost quite a bit in extra labor, but you will learn a lot more about making a surfboard than if you just got a close tolerance PU blank and glassed it with UV poly resin.
I was making EPS blanks for as little as $5 each. I have a bunch of 3inch thick XPS blocks I got for about $10 each. 3 inches is a little too thin, 4 inches is minimum, and 6 is great.
Hey everyone, thanks for all your suggestions, will do some work next week and keep you guys posted. Another thing i cant stop thinking about regarding the rocker, since I have a board that is 4" thick i was thinking of putting my nose rocker at 3.50 inches with 0.50 inches thick which means the nose will be eating up exactly until the 4inch mark of the blank, is this a good idea to start planing the nose from exactly 4 inches?
You should be able to get a bit more rocker or thickness or slop if you rotate your stringer in space. Leave the tip of the nose about where it is as a pivot, and rotate the tail up about one degree. The bottom belly will come up off the bottom of the slab. Then you can drop the whole stringer straight back down and you will have room all the way around. The concept might be hard to see in the board software, but it is easy to see in 2D CAD or once you have a stringer cut out of paper, cardboard, masonite…and hold it next to the slab. Are you able to export or print the stringer/rocker out from your software? If so, print it out on paper, tape it together, cut it out, and try it on the slab before committing to your real stringer material and glue.
Sharkcountry-
Thanks for the kind words. I don’t use regular Elmers for EPS. I had a bad experience once, could have been my operator error (too thick, never dried, leaked out, made mess). I use the brown/tan Gorilla PU for stringers and the clear/white PU for piecing foam to foam.
The one i posted is from an online software, it doesnt let me print it out but i was just using the online software as a guide before actually transferring it to illustrator or photoshop. I will do some print outs for the stringer later today and try your suggestion with rotating it around. You have any suggestions on what stringer dimensions i should use for this board? my template is a 6’6" eggboard.
You know where i can possibly get a hold on a stringer template? since this is my first board, was thinking to keep it simple and evaluate on the experience so i can use it on my next board (hopefully).
thanks for the tips!!! ill update you guys next week, unfortunately i only get to work on it during sundays cus i got work.