Making a hollow carbon board

[MrPotatoHead]

Hello,

I've been researching how to make a board as eco friendly as possible. What I'm aiming for is a hollow carbon fibre board.

I have access to waste pre-preg carbon fibre from the automotive industry and the equipment needed to cook this matetial. Rather than throwing this away I want to use it for something. As well as the board, I can make a mould from this waste material.
From a 2 part mould I can make a hollow board.

My background is pattern and mould making, not alot of experience in surfing.

I'm posting here for 2 reasons.
Firstly, if there are any problems with hollow boards you guys can warn me about?
The standard method of glassing onto foam, rather than using a mould seems a very lengthy process.
So I'm wondering if there is a good reason there arnt hollow boards on the market?
(such as hollow boards are harder to repair)

And secondly to see if anyone might be interested to team up. Ideally a shaper who has a board I can mould off, and who knows about this world.

Thanks, any advice appreciated, Chris.

[dtc]

Most wood boards are hollow (internal structure but not solid); so if you hunt around for issues they have you can probably find further reading.

The main issue is that the air inside expands/contracts, which can lead to structural issues and deformity. Easily solved with a valve.

Hollow boards are also harder to repair and more 'fragile'. A solid board can put up with quite a bit of damage and still float/be useable, a hollow board is more or less useless if the skin is breached as it then fills up with water. Also harder to repair, you can't just whack some resin or fibreglass over the problem. It takes skill to repair a hollow board; even for minor damage. That said, I'm sure skins can be created that are pretty tough and dont need much repair

I suspect hollow boards have other characteristics that are good or bad or different eg the weighting might be different; how do you put in fin boxes etc

One of the main reasons is that its much harder to tweak a mould vs a foam board - the latter you just sand a bit off if you want. So a mould is not really viable for anything other than a large production line producing the same exact board over and over - which is not how much of the surf industry works, its still a bit of a 'cottage' industry.

Dont know if that helps. There are hollow boards around (like said, wood boards are usually hollow), but its a niche area; carbon fibre I suspect is way too expensive to be commercially viable. There are boards with carbon fibre wrapping (rather than fibreglass) but I'm not aware of any fully moulded carbon fibre boards (not that I would necessarily, I just havent heard of any)

Sounds interesting.

[jaffa1949]

Hollow fibre boards have been on the let’s make one list ever since Fibreglass became common, , then with carbon fibre people thought that the flex and spring of carbon fibre pole vault poles could transfer to surfboards.
So let’s talk about flex in surfboards.
Torque flexional rotation about the central axis nose to tail. Wetted rail to unwetted rail and differences in how much rail is engaged in the wave face
Longitudinal flex, due to different pressures over the length of the board and wave pressure applied.

Compressional forces on the deck from surfer’s weight and applied force in turns.

Compressional forces from the wave both surfing and and wipeouts.

Torsion and flexing variably I turns from all forces applied.
Molded sections have an inherent weakness to all the applied forces at the seam. There is also material fatigue, particularly at joints.

There have been molded surfboards with foam blown inside the mounded surface, inevitably failure is at the seams.
Structural impact on surf obstacles and surfer’s carry techniques.

An air core needs venting. For temperature change or atmospheric pressure change when flying, even some of the cored, vaccuum bagged boards fail under these conditions.

Now let’s consider buoyancy, try duck diving a big balloon under waves, that will interesting, and then how much you can engage a float in turns and other aspects if it is too buoyant, a lot of eps boards are tarred with the it’s too corky brush.

Design in rails important, rounded with a hard sharp edge or a progressive shape change through the area that will be needed as the rails are engaged. Hmmmm.
Crack the enigma of design and materials , it could be a winner. But lots of understanding of the arcane art of shaping ( mounding in your case) is needed.

[steveylang]

http://www.avisosurf.com

There have been other hollow surfboards before, but I guess this is closest to what you're thinking about? There are so many physical characteristics that influence how a board surfs, that making a good one right off the bat is going to be really hard (but if this is a 'fun' project then that's probably part of the fun.)

But you might learn some good things studying their boards.

If you're not an experienced surfer this probably won't apply. But one of the disadvantages of hollow surfboards is if it dings (much less breaks), you're could lose buoyancy very rapidly. It would be tough to have that happen out in the water at a big break, and have to swim back to shore.

[SnakePlissken]

Have you thought about making a shape out of wax with a skeleton in it, placing the carbon fiber, then heating it and letting the wax out a drain?