Hi All,

Just registered yesterday. I've been looking at this forum for quite a while, mainly because I am interested inmaterials in general but also because I've been thinking about making my own carbon fiber parts.

First some general introduction about myself maybe. I studied chemistry (engineer) and wrote my thesis about flax fiber reinforced plastics (back in the days when this was a novelty) so I have arather good idea of the theory behind composite materials. Besides this, my big hobby is biking, I've raced MTB, road and even did a bit of trial. I also enjoy building my own bikes (that means everything including wheel building etc ...) but until now, I only used commercially available parts. By building this bikes,I became more and more disappointed about some parts, so I decided to build them myself out of carbon fiber. This "thinking about building my own parts" started about 1 year ago.

To give you an idea of the parts I am wanting to build, I want to make a one piece carbon fiber mudguard and a one piece chain guard too. In this regard I must add that I am only concerned about performance gains (weight/functionality), cosmetics is the least of my concern.I've never won a beauty contest with my bike and I never will.

So the questions I have now are:

- Do I need a positive or a negative mold?

- Should I use prepreg or wet layup ?Are there any differences in strength of the finished product ?

- I think vacuum bagging is too complicated for this kind of more complex parts, no ? Is it necessary to use vacuum bagging or can I go with curing in ambient air ?

Oh and apologies for the bad English, it's not my first language.

Regards,

Ivan

 

Hi, Ivan

Hi,

I've sent you a mail.

Isn't infusion also complicated to get the resin in the correct places when making complex pieces ? Vacuumbagging has drawn my attention, maybe I'll need to learn about it.

For the moment, I only have two positive molds, no negative. My plan was to try with the positive first as they need less work to produce and if get more and more experienced with carbon, start using negative molds.

Best regards

Hi,

hello Ivan !
you can make parts with room temp epoxy and simple molds.
cut and lay out 4 layers of your cf fabric and pre impregnate each piece. be careful picking it up
and dont mess up the orientation of the cf strands. i believe they are called warp and tow. this manner is called a hand layup.
composites terminology
the correct amount of resin will be slightly more than the dry weight of your fabric.
best pratices are to mix epoxy by hand for 5 minutes(you MUST be thorough) and then pouring that into another cup will help mix and
get what you are working with away from the original cup and any possible incomplete mixed epoxy.
if you have dripping wet cf you have too much epoxy.
if the parts puddle you have too wet of cf cloth.
read up on cf health precautions--
use the highest rated respiratory protection you can. be careful this stuff can be like handling razor blades with bare hands.

scott

CarbonFiberCreations