Kevlar/ Carbonfiber gas tank

When I was at Colorado State University in the ME undergraduate program, we did a solar powered car out of carbon fiber. We used the epoxy/carbon fiber weave cloth and wrapped it around a shaved piece of high density foam as you described. You can make a cutting device out of a heated wire to shave the foam as you like.

We'd spread the epoxy on a flat surface since it's pretty thick. Then put the carbon fiber cloth down on top of that and use a drywall spatula or flat piece of plastic to push the cloth down onto the epoxy to completely saturate the cloth. Basically, using the plastic as a squeegie. Then it was applied over top of the foam.

For an oven we used the insulating material that has the aluminum foil coating on one side and made a structure that we could put the car frame into. Then we used heat lamps for curing the epoxy. It worked very well and the structure was very strong.

I think we used a shopvac and plastic sheeting for a vacuum bag but it was 15 years ago so who knows, I could have killed those brain cells by now. :devil:

I don't have any pictures because my GF at the time took all my film into a 1 hr photo place and they destroyed my negatives by mistake. I was pissed since this was something I worked on for almost 9 months. :awww:

We also made suspension pieces for the front end of the car out of 2 flat pieces and 3 blocks. One large block in the middle under the chassis and 1 block on each end with the carbon flat pieces on top and bottom. This put one piece in tension and one piece in compression and also kept the wheels at the same angle as the suspension compressed.

I have a carbon skid plate and pipe guard on my 300 and they seem to be fairly damage resistant. The skid plate is probably 5/16-3/8" thick however so I'm not sure if there is really any weight savings here.

Post some pics when you are done. :thumbsup::lol:

I don't have any pictures because my GF at the time took all my film into a 1 hr photo place and they destroyed my negatives by mistake. I was pissed since this was something I worked on for almost 9 months. :thumbsup:

Post some pics when you are done. :devil::awww:

And don't let the GF take them into the photolab for you :lol:

how does fuel through years of use affect the kevlar carbon material?

Compostites are great in beams etc, because the load direction is the same as the fiber orientation, but in a fuel tank all of the load (in a crash) is going to be perpendicular to the fiber direction. The tank is going to have to be thin (for weight), so when it hits the dirt, it is going to want to bend and the epoxy will crack. You want to make the tank stiff enough that the epoxy doesnt bend, as in the cured state it is quite brittle. Neither material is particularly suited to this type of load.

Also, using a carbon/kevlar weave is not going to help you. In some cases, mixing the fibers ends up better than one or the other. In a transverse load, either the carbon or the kevlar will break first, and it will be the one with the higher vallue of stiffness/elongation at failure, namely the carbon. This does not mean that the carbon is the weakest link, it means that for two different materials with equal strain, one is going to take more load. I would use either carbon or kevlar over a mix of the two. Kevlar is an awesome material on its own from an abrasion and durability standpoint, but the epoxy will be the weakest link.

If i wanted to make the lightest fuel tank that will survive a crash (or at least not start leaking), i would weld one out of aluminium. Like these guys do: http://www.praga.co.uk/cd610spc.htm

Also, carbon isnt that expensive, its just that it is difficult to work with, thats why aftermarket carbon stuff costs so much.

First off, I didn't give her the film, she stopped by and took it because she was making me a collage with tons of pictures for graduation.

I'm married now anyway so it doesn't really matter. I hate those 1 hr places. :thumbsup:

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