Flax Fibers in composites (interesting YouTube video)

I’m interested in using flax for glassing boards and thought this was an insightful video


That channel has a bunch of other really good videos too. I especially like that they do the tensile break tests so there is some real-world empirical data on the strength of the materials used.

Anyone have any insight on using flax cloth to glass boards?

Strength looks to be about half that of s-glass based on the tests done in the video, so that’s a bit problematic for durability.

I’ve done a handful of hemp deckpatches and tail patches. I’ll  use it if it fits the aesthetic of the board.     Once laid up, the cloth is very strong and it works great for patches, but the cloth is also extremely resin-thirsty so there are carbon-use tradeoffs with resin usage which go against whatever the savings there are with the cloth.  Not to mention the weight.  



These are the guys I bought my cloth from.  It comes in 60" widths so a $16/yd fabric isn’t really that expensive.   The color does turn darker when you hit it with resin.   


I’ve followed that YouTube channel for years.  I’d feally like to do forged carbon fiber fins the way they demonstrate the process in their videos.

Regarding flax, I don’t think I’d ever hand laminate something like that.  You need something like that under a vaccuume.

I use a vacuum bag.  Wet layup with release film and bleeder cloth.   Under moderate vacuum I recovered very little excess resin.   I think the only way to maximize the resin/cloth ratio is via resin infusion, which is a process that I have never attempted.    

By the time you get into vacuum bagging the additional carbon footprint of the equipment and consumables involved is probably offsetting most of the savings when compared to using domestically produced fiberglass.     Being eco-trendy might help you pull more hippie chicks at the beach, though.  If you’re into that sort of virtue signaling.    

IMO, the greenest surfboard you can build is the one that stands the test of time in both design and construction so that you never have to replace it.  That’s how a “dirty” PU/PE build of a proven design can be a much greener solution in the long run than a succession of boards with the more fashionable designs and fashionable construction techniques.    

Thanks for the insight into hemp gdaddy.

Your experience backs up what I’ve read about hemp being resin thirsty.

Flax seems to be similar depending on the weights and does seem to prefer being bagged.

Sanded AU has an interesting flax/basalt hybrid:


Among a bunch of other interesting fabrics:


I 100% agree on the “greenest surfboard” concept. Durability is the greenest attribute to chase. I’ve gotten to the point where shapes/construction are fairly dialed on proven long-term - 10+ years (using my friends in the industry, not my own work) and am looking into the next step of incorporating more natural materials.

There’s still some gains to be had there:


Realizing that this isn’t going to change the world, but as a passion project it’s a fun route to go down.

I’ve been really impressed with how well cork works in surfboards, having ridden cork boards now for 10+ years.

Those fins look good!

Another interesting link to natural materials being used in composite structures:


Mako, forged fins would be interesting, but that’s a whole other thread :smiley:

In Europe flax (linen) is often use in composits. Local products specific for composit are fine. Flax is lower density so at same weight need more resin than glass. Notox surfboards make a business with it. Fanatic use it for their eco build, earth boards from bic too, and many others. I use some, glass by hand, need some care like other light fiber. 

I have never seen those hybrid cloths in the US , I would be interested to try some of them .

Hi everyone. I have minimun shaping experience, but do you think that something like this (osnaburg) could work, at least for deck patches? Maybe is not tight enougt, i don’t know.



Looks good for me but seems a bit thick so may be need more resin so weight will be high. You must glue it with resin and not saturated it like fiberglass. Brush resin on a sealed surface, lay and push fiber in with a bubble free compacter roller, let resin infused and add some over if needed lightly and spread/roll it firm. Fiber must look on the dry side. When resin is set at B stage cover with others layers (clear resin, fiberglass, syntactic foam…).

Thanks Lemat. I’ll give it a try. Is a cotton fabric, known as osnabruck in europe, but a little bit thinner than the original. 


Cotton is short fiber, not good for tensil strength, can take lot of resin by expand while it’s wet. Good candidat as bulker between fiberglass to thicken skin with less weight than all fiberglass and keep some impact/perforating strengh. My be quickly too much weight for surfboards skin. Try to laminate it in a 50/50 resin/microsphere mix to reduce weight. 

Thank you, Lemat. Good tips. I guess that the same technique could be used with another fabric like this one (linen, etc.)…



So;  What is the advantage.   I can bet it’s not cost or price.  Most of these Hemp, Basalt and Flax fabrics cost quite a bit more than good old E or Warp fiberglass cloth.  Some(not all) are known to be not as strong as E or Warp.   Cosmetics ??  If you like the look, cosmetics are the only advantage.   I do suppose though something can be said for stiffness or flex.  Plus or minus.


Years ago we had that graduate student who was doing his thesis on surfboard materials, and he delved into the natural fibers. One of his observations was that the natural fibers were less consistent in their respective attributes. Meaning that one swatch might not have as much consistency with another swatch when compared to the manufactured fiberglass.

The other aspect that I don’t see a lot of discussion on is the hydrophobic properties of these natural fibers vs that of the fiberglass and various plastic fabrics. I mean, when you have to struggle just to wet out a plastic fiber with resin then that’s got to say something about it’s hydrophobics when laid up in a lamination. I always covered my veneers and hemp and other inlays with fiberglass, so those boards aren’t much, if any, greener than a conventional fiberglass layup.

Yes many studies show low consistency of natural fibers composits. Linen (flax) seems to be the less affected. Then water durability can be a problem but I think less with tissue full of resin than veneers embedded in resin. For me greener board is longer life board. If you can make it with lower impact products it’s better but my main goal is time durability, where plastic are very good in humid environment… 

Lemat–    Your emphasis on durability is the way it (the whole industry) should go.  But it won’t because of greed…    Since Covid it is hard to say how much influence cheap imports have.  But pre-Covid the markets here in the USA were flooded with cheap disposable CCP Chinese imports.   There are so many cheap short boards for sale on Craigslist.   If manufacturers were to concentrate on durability there would be fewer boards on Craigs and fewer in the dumpster.   Ironic that one manufacturer has a “Dumpster Diver” model.  If boards had some built in durability they would cost more , but be worth more.  Less depreciation.  As it is;  prices are up, but durability is down.  Which means you pay a lot for a new board,  but in a month or two, it’s not worth half of what you pay for it new.

Same here in Europe. I still think problem is consumers. They want more to pay less than to have real durability. They want to believe the “ultra light durable” marketing bullshit then they are a bit disappointed when they find it’s wrong, but they go again, so… Know pré covid they pay more for same shit but they still want it… It’s label on board that make price, I repair some full price channel island and Stewart so badly made! 

Yeah, the formula for a stronger board is pretty simple. Use epoxy and S-glass. Over a poly or EPS core.

A stringerless EPS glassed with epoxy and s-glass is about as simple as you can get and provides an extremely durable, light board that is highly repeatable.

I’m just curious to try and replace some of these materials with more natural materials now.