carbon fiber noob here, couple questions

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#1

What is the point of vacuum bagging a flat sheet of carbon fiber? I can understand vacuum bagging contours and 3D shapes but why a flat sheet, why not just clamp the sheet between 2 piece of glass?

Do I need to use an oven to cure then resin or can I just use room temperature curing resin? What is the point of using an oven to cure the resin, is oven curing resin better than the room temp curing resin?

#2

a bit of a noob to working with cf here as well, but what i can tell you is that what you’re asking is some very very basic questions. I would recommend you just read up on everything available in the forums, especially in the articles section (super useful).

As per your questions:

  • you certainly can clamp the two pieces between glass, but what you gain from using a vacuum bag is better control of where the resin goes when using multiple vacuum ports. Also you get more equal pressure distribution across the entire part (~14 psi depending on how good your vacuum is across the entire surface) vs clamping providing the most pressure where the clamps are tightened down hard.
  • you do not need an oven. This come down to the resin you use, some require heat to cure, but can stay a viscous liquid for weeks at room temperature, others will harden within minutes at ambient. Just depends on your application.

Again these are basic questions and i recommend you read up for now

#3

Vacuum bagging pulls air away from your part, together with the excess resin. Clamping the wet carbon fiber between 2 sheets of glass will most likely trap air under the glas. When you clamp it down, excess resin will flow out of the sides, but you will be forcing the trapped air into your part.

Most resins will have better properties once they have been cured in an oven (increased melting point etc.) This however depends on the resin you use. Usually I don’t bother doing this, because I don’t need the better properties from my resin, so it’s just a waste of time. But again, this also depends on what type of parts you want to make.