How to tell the difference between Black Glass Fiber vs Carbon Fiber

[x0054]

Hi all,

I recently purchased a HJ-Y3 tri frame. It was advertised to be carbon fiber, but how can I verify that it really is carbon fiber? I paid a "whopping" $10 more for the carbon fiber version and I want to know that I got my monies worth

I looked at it under a stereoscope, and I can see that it is indeed maid out of a woven material. But, I have no idea if it's glass of carbon fibers. I know that carbon fiber is supposed to be conductive, but how can I check that? Multimeter perhaps?

I guess at the end of the day it does not matter, I am just curious.

- Bogdan

 

[trigger]

Carbon fiber usually have a distinctive weaving pattern (that you can see with the naked eye).
Given the way that it reflects light, you should see alternating dark and bright squares on the surface. Look "carbon fiber" up on Google image.

Black glass fiber (G10), on the other end, is usually a solid color.

You can indeed test the conductivity with a multimeter. Carbon is conductive, glass is not.
However, carbon fiber is usually covered with a non-conductive coating (which gives it its glossy finish). Make sure to touch it on the edge with your multimeter probes (where there is no coating).

 

[x0054]

Thanks! I'll check it out as soon as I am back at home. Based on what you said, it looks to be the real thing, but the multimeter test will be the final tell.

 

[Cyberdactyl]

Plus carbon fiber is pretty light. Whereas G10 and glass fiber are a bit heavier. And yea, the conductive test is a giveaway as well. Make sure you do the edge, as the glossy finish may not conduct.

Here's some weights I verified.

2mm 3K carbon fiber plate: 1.9g/sq in.
2mm G10 plate: 2.8g/sq in.

 

[x0054]

So, got a chance to take a look at the frame under the microscope again and test it's conductivity. The frame is made from 3 layers of material. The top and the bottom layers are about 0.5mm thick, and are, indeed, carbon fiber. The middle material, about 1mm thick, is glass fiber, or something else. The outside materials are conductive, the middle is not. It is also different color, lighter than the outside layers.

The props I got are all carbon fiber, on the other hand.

 

[Tritium]

I bought a piece of 3mm Full CF sheet from an e-bay automotive vendor it was just 2 layers of CF over glass. Warped badly corner to corner as well.

Thurmond