Modern Fibers in Surfboard Laminates (Cerex and Others)

[img_assist|nid=1067382|title=|desc=|link=none|align=left|width=281|height=494]Better than Spray 77 for tacking down laminates.  Clear, not yellow,  quicker tack, yet doesn’t grab as quick, so you can reposition.

I used it to hold the fabrics to the foam.

On the left is a home made scrim of Carbon strands I pulled out of fabric.  Spray glued them to Cerex veil.  Really sloppy, but I have an idea to clean it up  for real use.  For regular use, I’d have to get roving, instead of pulling appart cloth.

Top right is the plasterers scrim.  I’m not sure what fiber it is made of.  Easy flex, so I don’t think fiberglass, but not sure.  It is covered in a rubberized coating.

Bottom right is the Ply-Tech sailcloth reinforcement.  It is Technora, with a plastic covering also,

I tried some scrim in Leno Weave, but the stands slide around so much, it made it hard to use.  When covered  a binder, they stay in place.  Just be sure the binder is Epoxy compatible.  All samples were covered with fiberglass cloth, and a layer of surface Cerex.  For apearance, the Cerex is semitransparent.  So the scrim looks milky white under it.


On the side, ever wonder how some board makers get a reputation for boards that stay white?  What do you think they do to get that look?

[img_assist|nid=1067383|title=scrim laminated|desc=|link=none|align=left|width=693|height=394]

I posted this on my build thread but if you haven’t read it here it is again.  Interesting stuff-


The Online Magazine of High Performance Composites and Composites Technology : CompositesWorld


Also saw this at erBB-


Lib Tech » Lib Tech Waterboards Revolutionize Surfboard Construction, an Interview with Mike Olson


I like the part where he says he doesn’t use any tape, brushes or sandpaper (I’m having problems with tape on my present build and am in the tedious sanding phase). 

Good stuff Mark.

Just did the puncture test on the last samples

All did better than simple laminates of just S cloth.

  • Carbon punctured, with the carbon shearing right at the puncture.
  • Technora had fewer fibers, with greater seperation. so it wasn't a really fair test of the materials.  Interesting thing.  The technora strands did not break at the puncture, but broke away from the hole, and pulled into the hole.
  • Cheapest plasterers netting did not puncture at all.
This confirms what is commonly known.  Carbon is nice and stiff, but when hit from the side, it shatters/ shears too easy.  Don't make car bumpers from it.

To really get accurate tests, I’ll need to get more accurate with the samples.  Equal fiber count, accurate placement, equal weight per square yard.

Could you post photos of the damage?  Also, I’m sure you’ve already thought of it, but, test with a blunt object?  That is what we really need to test for right?  The heel or knee, occasional elbow …and yes, head, blows.

OT I remember when I was researching hickory as a veneer, one of the things I liked was that is had the same breaking strength as human bones and was used in early crash test dummies…


ps If I ever make it up that way (still waiting for a swell to light up the points) I’ll bring you some scraps of 2 oz innegra to add to your laboratory.

Can you get innegra in 2 oz?  I got an e-mail from a vendor saying it only came in 5 oz!

With the stuff I’m doing i get dents from blunt impact, but never dings.  Penetrating impacts like rocks are what give me my dings.

Man, that is some pretty interesting stuff Olson was talking about. Wow, the sanding.

I’d be interested in knowing how plain weave carbon cloth holds up to yuor impact testing with a layer of Skinz/Cerex underneath.  Would be interesting to see if reduces fracturing.

Have you tried that?

The carbon sample I did had Cerex below and above.

Cerex reduces fracturing two ways.

  • if it is between two layers of cloth, it stiffens, by separating the compression and tension cloths.  It becomes a composite skin.
  • It also reduces fracturing because it is elastic.  As a glass fiber is tensioned, stress finds the weakest section of the glass fiber, and it fractures there.  If an elastic fiber is joined to a non elastic fiber, it spreads the stress point along the length of the glass fiber.  Giving it a little elasticity.  At least that is what the experts say.  Carbon has good tensile strength, but really poor flexing strength,  once it is forced to bend, it wants to snap. 
So if you are engineering the board to be stiff, carbon works good if fibers are run lengthwise, along the stringerline, on the tension side(the bottom) of the surfboard.  If you want impact strength, no dings on the rails, aramids are better.  Bullet proof vests are not made of carbon.  Airplane bodies are made of more carbon, and less aramids.

The trade off is, do you want it to retain its shape, or survive a crash?


I’m just interested in how Skins will effect impacts on plain weave carbon cloth.  I suspect it will help reduce fracturing and foam shear as an intermediary tension layer between the foam and carbon cloth – an inermediate tension cushion between foam and carbon that improves bonding with foam.

It will bond to the foam better, no doubt.  But lateral force from impact?  I’d cover the stiffening layer of carbon with an 1/8" layer of D-cell and then a surface skin of Twaron or Innegra.  D-cell sandwiched between layers of cloth is bombproof.  I’ve been doing that on my last series of decks.  Not a single pressure dent.  No footwells, nothing.

This is for your skateboard rails, right?

Just found a new resource

No.  I’m thinking about 6-oz carbon cloth over a layer of Skinz on the bottom for the XPS build.

Well, carbon adds stiffness. To keep cost down, Make a “skin sandwich”  Carbon outer layers with multiple layers of inexpensive skins as a bulker between.  That would make a semi low cost leaf spring.  But an individual layer of 6 oz carbon on its own isn’t all that stiff.

Then apply the entire carbon/skins assembly to the bottom.

Thanks!  I saw their website before, but it was so poorly laid out, I didn’t find it.  I searched harder and there it was!  No minimum orders either! Perfect for us little guys.

“D-cell sandwiched between layers of cloth is bombproof.  I’ve been doing
that on my last series of decks.  Not a single pressure dent.  No
footwells, nothing.”

So what is it you do not like about the
d-cell sandwich that led you on this path? Seems like you are going in a
totally different direction than that of a d-cell sandwich which you
describe yourself as “bombproof”. That seems to take care of #2 of your
requirements, then you need to work on the #1 - flex and #3 - cosmetics. 

You mention stringers in your flex equation. As a contractor I’m sure you are well aware of the significant differences between individual pieces of wood. This can be a big unknown in surfboard flex. By eliminating the stringer and replacing it with some sort of cloth, which tend to be made in highly controlled conditions to ISO standards, then you can greatly regulate your flex.

Also, remember that epoxy resin comes in different flex modulus, so if you find a “bombproof” build but it is too stiff, you can alter that buy just using a different epoxy.

Your sample experiments are interesting and will give you a better understanding of how the materials work with your desired materials, but they seem to be missing the larger context of a complete surfboard.

Just to throw something out there on your #2 requirement too, about price with regards to this comment:

“Marketing price point equilibrium would be making a board that lasts twice as long, and costs twice as much.”

I can tell you from experience in the retail space, that making a board that lasts twices as long you will be hard-pressed to get a $100-$200 premium over a standard poly board. It will require a massive marketing expenditure to even validate that price to the average customer. Remember, surfers are inherently cheap. There are pleny of examples of this in practice currently - Firewire, Coil, Surftech, probably hundreds of smaller shapers offering alternative tech builds. It’s rare to see these offered at more than a $200 premium, much less double. At double the retail price, you’re not going to sell any boards. Throwing expensive tech at it isn’t going to validate that price. Boards snap, period. 1 photo of your board snapped will invalidate all the marketing money that was spent on convincing your customers your boards are stronger/more durable and therefore worth the premium.

The key factor is performance. If you make a board that rides better, and as an added side-benefit is more durable, you’re going to do well.

I think this was the point you missed in the initial “train-wreck” thread that was trying to be made that you took offense too. The delivery may have been off, but the point was valid.

I’m all for what you’re doing, as I have ridden bamboo/cork/stringerless boards myself for years and am totally sold on the performance/durability of alternative build methods. All my boards are vac-bagged now and have been for quite some time. If nothing else, the inclusion of bagging into the build method increases strength due to better resin/cloth ratios.


Innegra makes a cloth that is  1 x 1 Plain Weave 2.2 oz 625 Denier Innegra (Prod. # 14420) that comes in 50" width.

Hope this helps.

Parthenon Surfer,

Do you have a vendor for your innegra 2 oz?  How much is it a yard?

Hi Lawless, 

Good interesting points, 

Just to get it out of the way, what crashed the other thread was some posters who wanted to keep their secrets to themselves.  I got that from both public and private posts.

I haven’t given up on d-cell.  It still is a very valid construction method.  My goal is to put as many tools in my tool box.  Knowing all the properties of all different materials lets anyone design a board for their requirements.  Changes in flex and flex zones.  Isolated impact reinforcements.  It is all about knowledge.

The future to the better performing board is not in just knowing the materials, but designing with them.  Even with current trends, do you really want to cork the entire deck?  Why?  Are you ever standing on the front two feet?  A board should flex differently in different areas.  Less flex in the tail goes faster, but is stiffer.  A good shaper needs to think about everything, not just cover it in e cloth, and what ever happens, happens.

And you are so right about pricing.  A Coil should be a thousand dollars.  A Channel Islands PUPE should not be seven hundred dollars.  A lot doesnt make sense, and marketing is huge.  But I don’t make boards for sale.  I’m a friends and family builder.  I’m just putting all this out there for other Garage builders to play with.  Pro builders should already know everything about this stuff.  But that was why the first thread wrecked.  Pro builders don’t want the Garage guy’s competition.


I got my Innegra from Scott Cambell @ SC Enterprises (132 North St,Vicksburg MI, 45097). His phone # 269/475-5024.

I can’t speak for accurate pricing as it was over a year ago the last trime I used it, but then I think I paid about $10/yd + tax & shipping.