epoxy carbon rail crease same spot twice

Hi all, first post I usually scan to get ideas on repairs but this time need some assistance…

I searched the net but could not find a crease thread which included the surfboard suffering from a second crease in the same area down the track…


I creased my 5’11 eps carbon railed board back in April 2014… repaired as per Haydenshapes and the actual shapers recomendations. It was a minor deck only crease with the rails just slightly cracked.

Here is what I did to repair:

  1. sand back deck glass and rails.

  2. cut crease deeper and glue/fill with 2 part pouring foam…

  3. sand pouring foam to a just shy level of the decks glass and fill with spakkle/spack filler and sand to flush.

  4. add new carbon tape to cracked rail area, 1 foot over the crack each way.

  5. 2x 6oz diamond pieces of glass lapping the rails a good foot over the bottom.

  6. add top layer of epoxy. wax. surf


So that was my repair, surfed it maybe 30 times since in heavy beach breaks and big reef breaks, took a few falls, sets on the head and late drops and have creased the board for the second time. In the exact same spot…

The only thing I noticed in the past week before the second crease is that the area of the original crease which is the area filled with spakfiller started to delaminate off the two part foam and I pressume this is why it has creased in the exact same spot…

Would experts here agree???


So round two, what should I do differently to make sure the spak filler adhears to the expanding foam underneath and will not delaminate again…

Or should I use a epoxy micro balloon mixture instead of spakfiller over the 2 part foam?


After the first crease there was NO noticeable performance loss or feel with the board so I am happy to have another go at the reapir…


below photos is as per my steps in picture form


and here is the board after the second crease…

as you can see the crack has followed the original crease line again…


Way to much spackle. Spackle work only if it’s full of resin. 2 part foam is not so good too, use a epoxy micro thick mix. I stop make and repaire carbon rails boards, every time problems.

ok, would you suggest I re fix as my initial steps but with epoxy micro instead of spackle?


if the foam is < 1 lb/ft^3 (or insert your standard foam density here), water will have severely weakened it where it creased, so most likely if you don’t really provide more support across that same stress line, it will happen again, and again, and again… high density insert will stiffen, and force the stress there.  There are lots of suggestions in prior threads if the search still works.  take care when sanding that stuff.

i made that mistake once too…now you know how not to use spackle…

So that was my repair, surfed it maybe 30 times since in heavy beach breaks and big reef breaks, took a few falls, sets on the head and late drops and have creased the board for the second time. In the exact same spot…

…And you are suprised that the board broke twice?.. Right now your best bet is to walk away. Buy a new blank and start over…after you build a new surfboard…maybe we can talk…

…but you don’t want to talk to me… talk about that big square black patch in the middle of your surfboard…the hinge…the breaking point…

sometimes brand new custom surfboards break… even in weak San Diego waves…or massive heavy stuff…



this was custom made by a reputable shaper… not myself.

Are you saying the black resin tint is a weak spot and it is not just a coincidence that the board broke exactly along that dark black line and dark grey line?



I told you that you do not want to talk to me. You do not want to hear what I have to say. The first photo you posted tells the whole story. Surfboards break. There is no reason to repair this surfboard. After you get a new board we can fix this basket case. Time to bite the bullet and buy a new board…Never square off strips of carbon cloth 90* to the stringer…no… your photos show that you did not do a proper diamond pattern on your repair. Time for a new board…we can talk later

I want to talk to anyone who can help!!!

got a new board this is my project now.

there is 2 x layers of 6oz diamond pattern glass,  although the top layer is squared off at the back end of the board where the black meets orange.

Im not sure what you mean with the carbon being 90* to the stringer? It is simply carbon laid over the rails as per Hapydenshapes instructions of how they repair snaps and creases.




the board broke 2 times. at what point do you throw in the towel?

Stingray this is not carbon on deck, just x glass black tint lam. Another new good idea, black on eps, LOL. The higher buckling stress, what initiate board snapping, that can experiment a surfboard is on top of the deck, because of quadratic moment, basics of mechanic engineering. Effective reinforcement have to be at this place. Reinforce rails increase positively overall stiffness, and durability against dings but light stringerless carbon rails boards crease like yours quickly.

Cheers Lemat, I am starting to realize that the eps carbon railed baords are no where near as strong as a stringer equiped board. Many folk who have these baords seem to be suffering from snaps and creases, I wouldnt buy another especially for the coastal conditions around me.

Anyhow, I am happy to learn along the way, it builds my skills up with resin/glassing etc and is only a few bucks in glass and resin along with my time…

I will take the advice from above and give it another shot. if I get any more sessions out of it im happy and Ive learnt .




here is an idea to repair that break. Use a router to remove the original repair and get into clean faom Maybe 1/2 " deep now  a sheet of divinacell cut to match the routed out space.
Epoxy the Dcell in place using micro balloons as filler. paste should be like a soft peanut butter constancy. use wights to hold down the Dcell once set shape the dcell to match now simply re-glass the repair with epoxy. a an opaque color to hide the patch. This should hold up under stress.

gee, you would think at some point a stringer (or two) would be installed

maybe one when the board was made

that board has no I beem structural integrety

just wraping the rails in carbon wont cut it, false sense of security

I fixed one that snapped 4 times before I gave up. The board musta weighed 15 lbs by then. I believe someone has it hung on a wall somewhere, ugly patches and all.

Thin rails, no stringer, eps core = snap unless you stiffen up the rails a lot (18oz)

These boards use x-glass as Lemat said.  the weave of the glass allows it to flex very easily creating a lively feeling board.   I use the stuff on my epoxy alaias for that reason.  the flaw in the design is that the x-glass is awesome stuff, but its only used on the deck, so the bottom and top have completely different flex patterns causing either side to buckle depending on the type of impact.   The thin strips of unidirectional carbon do little to strenghten this design because they don’t wrap far enough on the top and bottom.  I’ve seen a ton of these boards fail in this same manner.

Informative post, hofnar



The highest stress areas could be helped with more than one layer of carbon.