Me and Wozza will agree to disagree on this one though: I do believe prepreg is more advanced than resin infusion. Mainly because the resins in prepreg are more advanced in their nature. The fact that they cure at a higher Tg and are therefore more viscous, means the curing cycle is that much further ahead and mechanical properties are better. Going further in terms of resin performance, there's a high temp structural epoxy prepreg that Im gonna sample soon which has a Tg of 320C () For it to have those characteristics means the resin in the prepreg is so viscous, its actually in a B stage form. It cant even be handled by hand, it has to be pressed. On the other end of the scale, resin infusion in its nature uses watery, much weaker resins. To get equally performing parts, you have to use more material with infusion, making it heavier. That along with the fact that you can choose any carbon cloth to make your part. With prepreg, the standard modulus for fabrics used are much higher. I do agree that you can probably control the resin ratio used (apart from what lands in the catch pot and what is left in the feed pot, but with prepreg if you want to lower your resin content, you can use a peel ply. You wouldn't want to lower it anymore than that though.

An interesting trial was made by Gurit. They made some blades by infusion and prepreg. Conclusion: prepreg blades outperformed infused blades in mechanical properties and production value (20% more blades produced in the same amount of time). Infused blades cost less in materials, although prepreg cost less in labour.

Not to diss infusion though. I think its got its place (bonnets, boat hulls etc). Just because I don't do it day to day doesn't mean I wouldn't chose it for a particular job if it called for it.

What he said...

Lets face it F1 chassis are not infused and Pr-preg is the material of choice for the highest spec parts.. I wouldn't think I could get my seat/fuel tank down to less than 3Kg and be structural any other way....