The cost!!!!!

And carbon isn't more ding proof either, it's a heap stiffer, you could use 1 layer of 2oz and have the same stiffness as your 2 layers of 4oz glass. But touch it with something hard and half sharp and you have an instant hole.
That's the prob with carbon, it's so stiff there's no give, the load from a hard point contact, is taken at the point of contract only. Where as glass has a bit of give, allowing the load to be spread over a bigger area, you'll get a bit of a dent, but not a fracture.

I use carbon as reinforcement only, between mast and rear foot areas, I really don't think you gain much by covering the whole board with it.

I made a board for Hardie a while ago, and used 1 layer 8oz carbon on the outside, when he came to pick it up, he dropped a fin on it, from no more than 2 feet up, and put a hole in it.

WINDY MILLER said...

decrepit said...

The cost!!!!!


I made a board for Hardie a while ago, and used 1 layer 8oz carbon on the outside, when he came to pick it up, he dropped a fin on it, from no more than 2 feet up, and put a hole in it.

whilst fantically adjusting his tie; did he say "thats another fine mess, i've got myself into!"


good work oly

your a funny man windy or is that Stanley

vacuum bagged timber veneer would be my choice.

impact proof and softer riding.

Hey Decrep,

I try to remember to put the fins in the box, not drop them on it

I didn't end up putting that extra strap on, didn't need it. Move the back foot just before you take the drop, really lean into the bottom turn, then wiggle along the wave yelling out YEEEEEEEEHHHHAAAAAAAA!!!!!!! as loud as you can.

Worked for me


Every time I ride it that board puts a big smile on my face

WINDY MILLER said...

decrepit said...

The cost!!!!!


I made a board for Hardie a while ago, and used 1 layer 8oz carbon on the outside, when he came to pick it up, he dropped a fin on it, from no more than 2 feet up, and put a hole in it.

whilst frantically adjusting his tie; did he say "thats another fine mess, i've got myself into!"

I certainly hope so Stanley

what happened to the carbon/kevlar twill? Impact resisitant AND stiff!

What about protection from flat landings etc. Would full carbon hold up better to the normal on-water punishments of a wave board?

decrepit said...


Have you had trouble breaking/delaminating your boards?

remember that whatever pvc foam your useing(divinicell ect) its resin thirsty,so before you layup, fill the divinicell ect with a dry mix microballoons or Qcells then you will know there aren't any dry spots in the laminate(aswell as incress the density) you must remember carbon isnt like Sglass where you can see if all of the glass is wet through, and allso when buying carbon make sure its for a normal layup and not for fusion layup
the fusion stuff has a coating called fiberseal and is very hard to wet out even with a wheel
and remember that carbon will absorb moisture, so make sure that you store it so it's airtight otherwise it will go britle, same as microballoons, keep them dry or you will be adding weight

crabs said...

Thanks for the replies. All food for thought.

To answer your question, Decrepit, my last board had a carbon bottom and it broke when jumping (cracked across the bottom). I had put previous glass/epoxy boards through a lot more punishment and was surprised that it broke so easily.

I thought maybe full carbon would take more punishment than just carbon bottom.

Seems like most folks agree that carbon is superior in strength.

May be your broken board is a case of reducing weight too much, because of carbons greater strength?

How thick was the sandwich? What was on the inside of it?

Did it break in tension or compression?

Normally the bottom "creases" when your feet at one end and the mast at the other try to bend the board over the water you've just flat-landed on. The stiffer the sandwich the more it resists this creasing effect. I've never seen a carbon bottomed board creased, but I suspect because carbon's so stiff, once the creasing action started, the carbon would just snap, instead of bending the way glass does.
I've also repaired some boards where the carbon has been sanded into during manufacture.
That's one of the reasons I put my carbon on the inside of the sandwich, the creasing action puts it more under tension than when it's on the outside of the sandwich, where it's more in compression. Also the carbon is protected from impacts by the outer layers.
Running the carbon at weave at 45 deg also means that all the strands have to fail, not just the ones running along the board.

decrepit said...

May be your broken board is a case of reducing weight too much, because of carbons greater strength?

How thick was the sandwich? What was on the inside of it?

Did it break in tension or compression?

Normally the bottom "creases" when your feet at one end and the mast at the other try to bend the board over the water you've just flat-landed on. The stiffer the sandwich the more it resists this creasing effect. I've never seen a carbon bottomed board creased, but I suspect because carbon's so stiff, once the creasing action started, the carbon would just snap, instead of bending the way glass does.
I've also repaired some boards where the carbon has been sanded into during manufacture.
That's one of the reasons I put my carbon on the inside of the sandwich, the creasing action puts it more under tension than when it's on the outside of the sandwich, where it's more in compression. Also the carbon is protected from impacts by the outer layers.
Running the carbon at weave at 45 deg also means that all the strands have to fail, not just the ones running along the board.

Hi Decrepit, that was a production board. Sounds like either faulty construction, poor materials or I was just unlucky. It broke in compression.

keef said...
here's your answer to delamination crabs, do your math's http://www.jp-australia.com/2008/index.php?id=35
why is it soooohere we have 110lt with all that lay up( pads ,wood, 2 layers of sandwitch,finbox ,mast track, ect,and it weigh's 6.3 kg's, if you do you math's theres no room for resin,
so the way i see it JP use the lightest core, with the minimal amount of resin so therefore delamination
how many times have you seen a small dent on the nose(top) and a huge crack on the bottom about 6" long, has anyone got the answer, why is it soooo

Hi keef, interestingly it was the lightest board I've had.

That's why I asked in my initial question whether if I used the usual amounts of cloth and resin if I could expect to get a stronger board if made out of carbon. Seems you guys agree that it would be stronger, if built properly.