what is pre-impregnated cf? how does it work? :?
Pre-preg is short for preimpregnated resin reinforcement. The carbon fiber that you buy already has resin soaked in it. You just need to lay it up and vacuum bag it instead of having to brush the resin on. It’s not as simple as it sounds because prepreg requires high pressure and high heat to cure. That also requires your mold to be built to spec so that it can handle the high heat for a long period of time.
so its dry? and you have to heat it to get the resin to “melt”?
in lamens terms yeah. But you need pressure as well.
how much pressure?
pressure from an autoclave.
riiiight, but how much pressure is that?
It depends. Most autoclaves will produce a 100 or more psig depending on their design. Also they can be heated and pressurized with a inert gas. You’re getting into processes that are expensive both in equipment and materials. If you have specific requirements for the performance of the final part, then that will tend to point you in the path of the necessary process to produce the part.
or compression.
or vaccum bagging 
I’m doing some tests with different compressions now. My attempt at a vacuum bagged part worked…well…minus the fact I HAVE SHIT PREPREG.
thank you TMI Inc…
anyways.
besides the already said…yeah, CF that is frozen and sticky.
I have done many compression molds (aka, 2 Alum. plates clamped with C-clamps), and have gotten some nice and light plates.
I also tried some normal home oven vaccum bagging peices (and ended up killing my silicone mold…grr), and they turned out very well!!!
autoclave helps…but…hightemp vac. bagging works too.
it’s great stuff if you get the right stuff. My pre-preg that I got from TMI Inc was non-visual stuff, so the epoxy is yellow…looks like crap, but it works.