Hi I’m the new guy here!  (See http://www.talkcomposites.com/21718/I%E2%80%99m-the-new-guy-from-Oregon-USA)

I want to produce a mold that will allow me to have finished molded surfaces both inside and out on the component I'm producing, which will have a high degree of structural definition both sides.

From some videos I’ve seen it appears I need to make a closed mold for vacuum infusion, which may require the mold to split lengthwise and again on both ends with this particular part.

The exposed outer surface of the finished part needs to be a cosmetically perfect twill weave pattern and the only way I can figure out how to orient the fiber do this is pre preg on the 1^st layer.

The subsequent layers don’t need the cosmetics, so do they need to be pre preg, or can they be vacuum infused with wet resin in the same mold then baked in the autoclave?

If what you want to do is "produce" and sell multiple counts of this part, then Prepreg all the way through is the way to go. 

I have made quite a few small complex CF parts using closed aluminium moulds and infusion.  Getting "perfect" cosmetic finish on all surfaces of these has never worked faultlessly.

I decided to not bother, since I wanted to secure the parts against UV damage anyway, so all "non contact" outside surfaces are clear-coated.
(by "contact surfaces" I mean the areas of the part that is "covered" by the stuff they are clamped to/ screwed on to.

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