Talk Composites - The Forum for Advanced Composites

Right mandrel/mold for 90° bent carbon fiber tubes

http://www.talkcomposites.com/Topic6101.aspx

By zeiss - 5/16/2013 2:18:41 AM

Hi all,
i'm buying some carbon fiber sleeves like the one in the image..
roughly 20 cm right + a 90° curve + another 20 cm right
with the diameter of 21 mm.

Upon your opinion what's the best and simple mandrel to create..

A copper tube rounded with pipe insulation foam...?
I read in some article that it could be the right solution..
I think only that it should not be so easy to take out 
the copper tube once the carbon fiber is cured..

I imagine a different solution, the opposite of the previous one.
I would like to try to use  a rubber hose of roughly 45 cm 
( those used to water the garden). I do not know the technical term (I'm not native English speakers ..)

The outer diameter of the pipe must be equal to that which you want to obtain less the thickness of the sleeve of carbon fibers.

Then I would insert each of the two ends of the rubber tube two pieces of an adequate diametered rigid tube (aluminum stainless steel ...) 
for a length of about 15 centimeters into the rubber hose...
 Then I subdue the rubber tube by holding the ends of the two metal tubes and would insert it into a kind of template that keep it fixed and positioned so as to create the shape I wish.  I_

once the carbon fiber is cured... i think that it could be more easy to take off the carbon fiber tube the mandrel..
First i could take off the metal pipe from the rubber hose..it should be easier than the first idea..
Tha pipe are straight... Then taking off the rubber hose from the carbon fiber tube created it should be not so difficult 
because rubber i think it's more easy to go in the curves than copper.... :-)  

What do you think about my idea...?
It might work ..? This will be my first attempt in the world of composites ..

Do you have any different ideas or suggestions..?

Thank you very much for taking the time in answering.
By Warren (Staff) - 5/20/2013 10:02:08 AM

Theoretically those figures look about right.  How close you get in practice could vary slightly.

Silicone generally does not stick to anything but itself.