Hi,

I am trying to make a stool with braided carbon sleeve 20mm. I am wondering how sturdy it is with epoxy resin. Is it durable enough not to snap bearing the body weight like links attached below? Otherwise, could you give me any advice to make it harder as a seat?

Here is links as an example. 

http://www.dailytonic.com/carbon-fibre-seats-by-peter-donders-be/
http://www.artnet.com/Artists/LotDetailPage.aspx?lot_id=9C9BAD102F4BAE377573FE6B1429EC8B

Thanks for your help.

Hi, Interesting project

Hi Yooou,

It is an interesting project. I've actually worked with a few other customers on similar art/furniture projects, some with great success.

Of course, it really depends on the inherent strength of your design and exactly how you implement the use of the carbon fibre but my initial feelings are that a single layer of carbon fibre braid would not be strong enough to form an integral part of the loadbearing structure of a chair/bench. Doubled-up or even trippled up then I expect it would be a single sleeve of 20mm braid only has a wall thickness equivelent to a 318g carbon cloth. There really isn't much in composites that you can make with a single layer of carbon 300g cloth.

The twisted-tow type projects (like the first link you included) normally use quite a thick tow of carbon fibre, I believe something like 3 layers of the 'spread-tow' (removed from a spread tow fabric like our 15mm Spread Tow Plain Weave Carbon Fibre). The 3 tows can be stacked on top of eachother and then lighty misted used activated epoxy resin sprayed lightly onto them to make a loose bound carbon fibre strip (still very flexible and 'dry', but held together enough to be useable) which is then wrapped around the form and then wet thoroughly through using epoxy before it's all cured and then the sacrificial core removed).

Like Matthieu says, the essential thing with this kind of art/experimental composites is to to small samples and test the performance/results until you get the results you need.

I hope this helps and look forward to working with you.

Best regards, Matt

Matt Statham
Easy Composites / Carbon Mods - Technical Sales

Hi Matthieu,

Thanks for your advice! It is a nice lovely chair. I will apply one layer of carbon fabric at first and see
how more layers I would need.

Hi Matt,

Thanks for your opinion. I got a few more question.

I have ordered 5m of cf sleeve and IN2 resin for testing. How can I apply resin to the sleeve? Using brush? Dipping?or Spray?

To get a nice finishing, what should I do with the surface of sleeve after it cures? As you said, would a spray gun make the surface smooth?

Thanks for your help.

Hi Yooou,

How can I apply resin to the sleeve? Using brush? Dipping?or Spray?

I would suggest that brush application would probably still be best. Dipping might work, providing that you agitate the braid enough whilst it is in the resin, so that the resin can wet the fibres thoroughly. Spraying would probably not allow the fibres to wet-out properly so I would avoid it.

To get a nice finishing, what should I do with the surface of sleeve after it cures? As you said, would a spray gun make the surface smooth?

It depends what sort of a finish you want. If you want a smooth, glossy finish then it might be worth wrapping the sections with release film or shrink tape whilst they are still wet to make them less textured once they are cured. After this, you could flat them back and then either lacquer (clear coat) them or paint a layer of epoxy coating resin on them, before flatting and polishing that.

If you actually want a textured finish then you could just leave it in its natural state or spray lacquer onto the braid and leave it.

--Matt

Matt Statham
Easy Composites / Carbon Mods - Technical Sales