EPS Crease Fix

Hi all,

Posted this over on realsurf.com forums as well:

Seeking an opinion from all you board crafters…

Creased my favourite board, epoxy fiberflex, right in the middle of the board where my front foot lands. Sad times.
The crease has not gone through to the base of the board, just on the top deck and rails, doesn’t seem too severe, see photos.


Is it worth fixing? I’m thinking yes, but will the board be reliable again?

I planned to take it to sumatra and also Morocco later in the year… should I be looking to replace it with a new, reliable board?


Any advice would be appreciated, cheers


That, my friend, is the beginning of the end of that board. I’d replace it.

I like stringers.

Yeah, unfortunately that's exactly what I'm thinking. Fixing that crease would make the flex pattern be all weird? Stiff in the middle, so the strain would be transferred elsewhere in the board?

Probably worth fixing and just using locally, but not to take on a 2 month surf trip?

Has been a fun board for almost 2yrs (still looks new apart from the crease). Maybe time for a new one..


That, my friend, is the beginning of the end of that board. I'd replace it.

I like stringers.


Can it be repaired?..... yes..... Treat it as a broken board................

repair or replace as needed.

What Stingray said. I'll add this, if you fix it correctly, it won't break where the repair is. It's no more likely to break than a new board on your trip.

Thanks for the feedback, I’m thinking I should take it to someone who is decent at shaping/repairing EPS boards, see how much it’ll cost to get done properly…

If the quote is too high, I’ll have a go at fixing it myself (I’ve fixed many smaller board dings, just not creases).

From what I can read on here, I’ve simply got to cut out all the delaminated top sheet/ rail material and replace any voids with EPS foam where required and resin/glass combinations as normal.


Will let you all know how it goes!


There was a guy named 'Doc' who hasn't been around in awhile.  He was always good for repair advice.  One of the things he used to recommend was do NOT start with major surgery.  I think that applies here. 

One issue I see is that the stringerless board has the carbon rail and the carbon appears to have been compromised.  Because of that I would consider routing a couple of 1/4" wide slots about 6" apart in the deck - carried about a foot or so on either side of the buckle and insert some wood strips or carbon/fiberglass layup.  They don't have to be terribly deep - 1 1/2"- 2" or so will help.

I would then, with a coarse sander, feather away all of the loose/cracked material.  It may not be necessary to get all the way to the foam but you want to get rid of any delaminated material and create a depression about 3"-4" on either side of the buckle which will be filled with layers of fiberglass and resin.  Carry the fiberglass layers around the rail.  Fill coat, feather the edges and try to get it smooth. 

I wonder if there might have been some sort of dent or ding that triggered the buckling of this one?  If so, consider keeping up on such things.  If not, consider a stringer on your next one. 

I use to repair and experiment many tech, i found that to repair carbon rails, don’t use carbon but many layers of glass. All repair i do with carbon (5 boards: fiberflex and mine), crease again because add carbon stiffen to much. So i re -repair just with glass and it seems to be good.

As i am a mechanical teacher, i want to understand and modelize break of surfboards for long time. After many lab test, study of thesis, and with a powerful mechanical software i found that surfboards break first by buckling of compress side like all other sandwich panels with thin skins. What a secret LOL.

Stringer as reinforced rails stiffen board, that limit amplitude of flex, compress side is less destabilized so less buckle. No real difference, performance by weight) between those two solutions, against buckling.

Stiffer skins are far better (perf by weight). That’s compsand and other thickened skin (coil, libtech etc…) concept.

less skin is stiff more foam need to be “strong” near skin (hydroflex concept)

Sorry for my frenglish

Again, I appreciate the replies.

HS has said that considering the foam doesn’t look to be compromised, that the board should ride almost as new if it’s repaired properly, and that I should wrap the rail compromised zone with some additional carbon. Little bit of conflicting advice here, but I agree, I would’ve thought reinforcing with carbon would simply be too stiff for that area. Have asked HS regarding this and will see the response.


Have been really happy with the performance and reliability of this board, barely a dent on it, I believe the EPS is indeed stronger and more lively than PU foam.


Not a bad idea John, thinking it could be a valid option to reinforce the rail area with glass (first observing how compromised the carbon is under the glass), and lay some carbon insert through the deck a foot either side of the buckle. This should hopefully alleviate the stress within this area by spreading the force over a larger distance. Just means I have more area to feather through to the crease zone.


First thing’s first I guess, cut out the affected creased (delaminated) glass, see how the foam and rails look, and go from there. Could have an interesting project for myself.

Just sand down the effected area, and reglass with 6 oz., I will be fine.  Will it be the same...no, will it be heavier...yes.  Will it break in the same spot...no.

As mentioned above, there is no reason to do major surgery.  when a board breaks in two, the main goal is to get the board glued back together straight.  You have not gotten to the broken in two part, so you are ahead of the game.  Once the board is glued back together, all you do is reglass it about 6 inches over each side of the break.

Lots of guys want to put sistered stringers to shore up broken stringers etc, they want to wrap the crease or break in 3 layers of 10 oz cloth, ect. I'm telling ya all you need to do is reglass it.   The more you futz with it, the harder it will be to repair.

Compromised deck glass cut out, I’m just not too sure what to do with the rails.


Sand them back heavily and see if the carbon is still ok?

Cut through the whole lot back to foam and reinforce the area with a carbon patch that overlaps the existing carbon or 6oz wraps?

Fairly confident with the deck work, just not too sure how to approach the rail. Might even take it to a local repair guru and get him to do the glassing, but I’m keen to learn how to do these things myself too.


HS has said he always repairs with a carbon patch in the compromised rail and they ride good as new, getting a couple sent in the post so I can decide whether to use them or not.

We’ll see how it goes!


Hi all,

Is it worth fixing? I'm thinking yes, but will the board be reliable again?

I planned to take it to sumatra and also Morocco later in the year.. should I be looking to replace it with a new, reliable board?

Any advice would be appreciated, cheers



Yes it is worth fixing

No, don't take it to Sumatra nor Morocco !! Get a new and strong one for that trip [Coil makes pretty good ones]

bit too late… but next time… What I like to do before I strip the glass is to sand the complete area you want to patch. After that cut out the buckled/delamed/cracked area. This help keeping the foam intact.


I agree just using regular fiberglass and resin instead of carbon patchs.


worth repairing yes!

I would sand instead of cutting. You just introduced a step between the good glass and the foam, whereas if you had sanded it it would have been a smooth feather down… Like this _/  instead of |__| that. In my opinion it is easier to fill, and get this  kind of groove  _/  more even in the long run…


My friend had a board that was good, buckled it exactly like yours and had it fixed (a few layers of 6 oz s Glass laid over the buckle) and we both think the boards ten times better now. So … whatever. Plus I beat the isht out of it since then and it still surfs good.



I really wish someone would translate that french guys stuff. I couldnt understand it, but it sounds super interesting and its something I wonder about all the time…