I was wondering if anyone on here has previously or currently creates molds and lays carbon fiber. I am really interested in the process and would really like to talk to someone about all the details about what it takes and pros and cons. We could discuss on the forum, PM or by phone. Thanks!

Jake

 

I do some limited work as part of my job, so maybe I can help. What questions do you have?

 

first off, i would like to know how to create a mold. what products to use, the process, what are some good things to test out...things like that..thanks for responding.

jake

 

Sorry for the late reply -

If you're going to be making parts at home, then you'll probably want to use carbon fiber cloth and epoxy. If you're willing to invest more in higher-quality production, then pre-impregnated cloth (aka prepreg) would be better. Prepreg cloth is made of carbon fiber that has been impregnated with epoxy. Storage of the raw material requires a large refrigerator, and production of parts requires a large incubator. I imagine that these two requirements are probably more than you're willing to invest in.

Ignoring prepreg, a simple way of making parts is:

- Apply and buff mould-release (usually a kind of wax) on the mould.
- Brush a thin layer of epoxy onto the mould. This is called the gel coat. After the gel coat cures, rough it up with sandpaper.
- Lay the cloth on the mould, and brush epoxy onto the cloth. As the cloth becomes saturated with epoxy, lay more layers (called laminates) of cloth onto the mould.
- Use toilet paper to dab off the excess epoxy.
- Let the epoxy cure.
- Remove the part from the mould, and trim off the excess. (There are techniques for trimming off the excess before the part fully cures, which makes the process much easier).

There are many different kinds of moulds, and which type you choose really depends on the part. Silicone moulds make it easy to get complex parts released since the moulds are flexible. You can also make moulds out of carbon fiber, but need to be careful on how you will make the part-line for the mould to split in half. The mould is no good if you can't remove the cured part from it.

There are many different weaves and weights of cloth and there are different resins as well. It's not easy to make choices without experience.

Also, be very careful with the materials. Epoxy is toxic and requires use of latex/vinyl gloves and a good respirator. Carbon dust (from sanding the carbon fiber) is extremely bad for your lungs. Any epoxy that cures is very difficult to remove, so you'll need to have acetone to clean off your scissors etc before the epoxy cures.

The strength of carbon fiber parts mainly comes from how the cloths are weaved and in which orientations you lay down the laminates. A good surface finish for displayed parts (hoods, spoilers, etc) requires a mould with a flawless surface finish, and prepreg is almost a necessity since its use does not require applying a gel coat first. (The gel coat is the part that is normally visible and must have a good surface finish).

Composites work in general is quite expensive, especially when you're looking at carbon fiber. I suggest that you do not attempt to learn this on your own, but rather find a shop that can train you as you make parts for them.

 

Thanks for your response. I was thinking it would be a great idea to shadow someone...im sure there are a few around this area. thanks again!

jake

 

anyone know a cheap place to get both already compressed sheets of CF and also just the raw material rolls??

 

When I was researching all of this I found a bunch of distributors. Search through google for pre impregnated carbon fiber and carbon fiber rolls. You will find several places that sale it. Im not on my home computer so I cant tell you the exact links. Hope that helps.

Jake