im looking at laying carbon fiber for a project and need some resources to teach me how to do it and figure out how many layers i'll need etc...

i've helped a friend with carbon fiber before but it was just for looks and strength wasnt critical. for this project strength is very critical

anyone know of any good places to go for information or has some experience with it and wouldnt mind helping me out?

10/24/2005 7:07:11 PM

uh

how strong is "critical"?

Because simple layup may not be what you need?

10/24/2005 7:21:32 PM

im making a shell about 5" in diameter and inside contains stuff altogethor weighing less than 5 lbs. the carbon fiber will rest against an inner shell.

i dont want it to crack if its dropped or thrown

10/24/2005 7:27:25 PM

gotcha.

if I wasn't in the great white north,

I'd help.

but good luck!

10/24/2005 7:51:20 PM

When using carbon fiber for strength appliactions u must use do it like your making a sandwhich. I know it sould funny, but its true, u have to layer it. The material you have to put in the middile of the CF layers is this stuff called NOMEX or somthing like that. Its like a honeycomb looking material. It gives the support for the layers. if u have any more questions, hit me up
-Ben

10/24/2005 8:13:27 PM

http://www.rocketmaterials.com/data/fins/Bend/index.php

Thats a good link, comparing them, and showing what it should look like

10/24/2005 8:19:15 PM

Jon get up with Poe87, he has worked with it personally so he should be able to give you some tips

10/24/2005 9:09:30 PM

yeah poe directed me to his friend who answered a bunch of questions for me but now i need to know how many layers and need some advice for when its actually time to do it

^^i'll check it out, thanks
but i dont think honeycomb will work because i need a sphere

[Edited on October 24, 2005 at 9:17 PM. Reason : .]

10/24/2005 9:15:28 PM

Carbon fiber is the stiffest of all the FRP's, but still, a single-layer laminate is gonna bend pretty easily...as far as the "sandwich" composite layup goes, you can use damn near anything as the filler in between. The Nomex honeycomb does extremely well in compression, and is really light, but you can use styrofoam or balsa as the core material. I was thinking about using Corex corrugated plastic in a layup.

You HAVE to use epoxy in carbon fiber FRP layups. Polyester resin does NOT bond very well with CF.

10/24/2005 9:19:19 PM

is there anything to sandwich that i could make into the shape i need

i guess i could mill styrofoam

10/24/2005 9:25:52 PM

If you lay up at least three layers of unidirectional, each 60 degree oriented from the others, then you shouldn't need a core. It just makes it stiffer. Are you making a pressure vessel? If so, you don't need a core.

You could use the investment method. Take roving and wrap a styrofoam ball with it. Melt out the styrofoam with lacquer thinner when you're done.

10/24/2005 9:32:27 PM

well i was just going to lay it on the inner shell, its really two half-spheres

not a pressure vessel

10/24/2005 9:38:39 PM

anyone with experience that wouldnt mind lending a hand?
i'll buy you dinner or something for your help

10/25/2005 5:01:39 PM

I can help you, I have worked with composites before. Not a whole lot but enough to pick up a few tips. In the mean time go to http://www.rcgroups.com and search for "lost foam method" and/or check out the Composites Fabrication board.

10/25/2005 5:55:28 PM