Carbon-kevlar vs. glass fiber

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#1

Hi all,

I’m currently working on a float for a light airplane; it’s an hollow structure, made of two semi-shells bonded along median plane. It’ s a mix of solid laminate and sandwich with foam core and made with glass; up to now nothing to be worried about, but the owners asked me to change materials and substittue all the glass cloths with carbon-kevlar cloth. The structure is hand wet layup and vacuum bagged.
My questions:
are there some details of carbon-kevlar that I have to consider during laminating ?
has this material problems with pvc foam ?
are there other problems that I could encounter in using this material in place of glass?
Any help is appreciated

#2

Keep in mind that it is no see-through material, so the impregnation is more diffucult to see.

Cutting can only be done with aramide-scissors.

After cure, cutting can be done with diamond tools.

No problems with PVC foam or epoxy.

Thickness will be slightly more when the same weight of fiber is used (more epoxy)

Fabric is slightly less pliable, keep that in mind in corners.

#3

herman,
thank you for you very useful post.

One more question about the resin/fiber ratio in weight for carb-kevl: have you some value to suggest ?

#4

No idea about weight, but in volume you should be able to reach 40-45% fiber volume.

It is easy to calculate this to weights.

#5

ok ,I will start with these volume ratio.
Thank you again