ThreeFN
Member
Re: Daft Punk Thomas Bangalter helmet build
May need to be more than a few drinks :unsure
I've never been a fan of carbon fiber unless absolutely necessary for strength reasons, but then again I have no experience with using it in a 'cosmetic' sense. Normally I used it as a 'spar' for fiberglass wings, so it was layed up as part of the fiberglass wing skin.
Here's my experience with it as an 'aeroshell' on a competition plane a few years back:
1) The 'course' weave of the carbon fiber meant that is was really difficult to get a good surface finish without 'bubbles' between the weave and the exterior, ruining the smooth finish. We ended up using a layer of 0.7oz glass as the actual exterior surface so that we got smooth results.
2) Carbon fiber has a tendency to act like a sponge and pull epoxy into the weave itself. This means it tends to pull the epoxy away from the exterior surface, ruining the finish. In the above case, it tended to pull epoxy out of the fiberglass that was acting as the outside layer. In the case of a wing spar, it tended to wick up the epoxy that was being used to bond the spar to the wing foam core, making the spar less effective with a higher risk of delamination.
3) Carbon fiber cloth is stiffer than fiberglass and tends to resist bending more than fiberglass, making it harder to work with on curved surfaces. Normally this is fixed by vac bagging to apply pressure until the epoxy cures.
Granted, the above experience was with an airplane aeroshell, where weight was a crucial concern. A handful of the problems experienced above could probably be cured by simply adding more epoxy than the bare minimum like we were.
I would love to hear from someone with experience in carbon fiber 'cosmetic' items like body panels (and Volpin helmets) in the methods and approaches to use for carbon fiber. My experience came at the cost of extensive and painful trial and error. I'm sure that contributes heavily to my mistrust of it.
May need to be more than a few drinks :unsure
I've never been a fan of carbon fiber unless absolutely necessary for strength reasons, but then again I have no experience with using it in a 'cosmetic' sense. Normally I used it as a 'spar' for fiberglass wings, so it was layed up as part of the fiberglass wing skin.
Here's my experience with it as an 'aeroshell' on a competition plane a few years back:
1) The 'course' weave of the carbon fiber meant that is was really difficult to get a good surface finish without 'bubbles' between the weave and the exterior, ruining the smooth finish. We ended up using a layer of 0.7oz glass as the actual exterior surface so that we got smooth results.
2) Carbon fiber has a tendency to act like a sponge and pull epoxy into the weave itself. This means it tends to pull the epoxy away from the exterior surface, ruining the finish. In the above case, it tended to pull epoxy out of the fiberglass that was acting as the outside layer. In the case of a wing spar, it tended to wick up the epoxy that was being used to bond the spar to the wing foam core, making the spar less effective with a higher risk of delamination.
3) Carbon fiber cloth is stiffer than fiberglass and tends to resist bending more than fiberglass, making it harder to work with on curved surfaces. Normally this is fixed by vac bagging to apply pressure until the epoxy cures.
Granted, the above experience was with an airplane aeroshell, where weight was a crucial concern. A handful of the problems experienced above could probably be cured by simply adding more epoxy than the bare minimum like we were.
I would love to hear from someone with experience in carbon fiber 'cosmetic' items like body panels (and Volpin helmets) in the methods and approaches to use for carbon fiber. My experience came at the cost of extensive and painful trial and error. I'm sure that contributes heavily to my mistrust of it.
