Carbon Fiber

[Esteban]

When I built my walls I used 4 fiberglass oz. cloth for one wall and lighter (about 2.4 oz.) fiberglass for the other wall. The 4 oz had a more open weave and was easier to saturate. Both turned out well after I filled and sanded them smooth.

Fiberglass cloth that was lapped was pretty easy to sand out the high spots and smooth with a seal coat of epoxy that I then lightly sanded.

I have read about different fabrics and hybrid fabrics and do not know if any would be "better" to use. Carbon/kevlar is one I considered using in the front to better protect it from stone bruises. Would that be overkill?

Are there times it makes sense to built up layers of fabric? Maybe use carbon as the base layer with a top fiberglass fabric layer to make it easier to get a good smooth finish if you sand it?

I am thinking about using carbon tape or fabric in the front and rear to strengthen the lower "bumper" areas.

This discussion is timely because I soon want to buy more fabric and epoxy. Raka epoxy is what I used and it worked fine when I got the mix ratio right. I probably will buy a Harbor Freight digital scale harborfreight.com/digital-scale-95364 or harborfreight.com/digital-pocket-scale-93543 to measure epoxy and hardener more accurately than measuring it in plastic cups.

[Esteban]

Does seem representative of hand-laying carbon fiber?

It looks doable.

[Atomic77]

The only way to have a single looking piece is to make a mold. You can join them, then vacuum bag them and they will look alright, but you will still see the joint. Like I said previously...if you want it to look really nice, without painting it, you need a mold.

[Corwin C]

My experience with hand layups of carbon fiber is that no matter how much you try, there will be some distortion of the weave and because of the "grid" nature of the pattern (at least to me) it will look like it has defects. Using clear finish epoxy will give you the "shine" you are looking for, however, with the weight penalty of building up that layer to fill the weave. If you sand down to the fibers and make them "fuzz", it will destroy the look that you're looking for, so be careful. Also, the extreme strength that carbon fiber is known for and the "look" that I believe that you want to achieve is generally accomplished with pre-preg material where the matrix is pre-applied to the fabric and the parts are autoclaved in a mold under heat and pressure to get the polymerization to occur. The fiber/matrix ratio has to be very finely controlled to get that type of performance ... it doesn't happen without serious skill, training, and tooling.

Is it possible, yes, if you would be happy with possibly distorted weave patterns in the carbon fiber. Would it be stronger than steel and incredibly light, unfortunately most likely not. Another factor that I didn't notice mentioned is that you will have to protect the finish on occasion with UV protective varnish, just like you would if it were a woody.

[KCStudly]

If it is just the carbon fiber look that one is after, they have that in a vinyl wrap pattern, don't they?

Yup.
http://solutions.3m.com/wps/portal/3M/en_US/Graphics/3Mgraphics/Products/Series1080/

[michaelrsydney]

If it is just the carbon fiber look that one is after, they have that in a vinyl wrap pattern, don't they?

Yup.
http://solutions.3m.com/wps/portal/3M/en_US/Graphics/3Mgraphics/Products/Series1080/

Agreed, if the purpose of using carbon fibre is just for the appearance then either use a mould, like Atomic said, or a printed vinyl wrap.

Alternatively if the plan is to build light, strong and stiff panels then go ahead and use the carbon/foam/carbon sandwich method as a simple hand lay-up, or vacuum bag if you can to save weight and maximise strength. Whatever system you use the resin needs protection from UV light.

To make glossy flat panels (on one side) a mould is easily made by using a sheet of glossy laminated material (Laminex?) and laying up directly on that.

[mgb4tim]

To make glossy flat panels (on one side) a mold is easily made by using a sheet of glossy laminated material (Laminex?) and laying up directly on that.

You can wax up a piece of MDF to use as a flat mold for the sides. You would have to add some beading for rigidity using something like plastic pipe cut lengthwise or 1/4" landau foam and clayed into place. I do a lot of fiberglass work and considered it, but the cost outweighs the foam/canvas methods.

[KCStudly]

Doesn't really bother me, but I think you chopped that quote up a bit. Not my words.

[Lonewolf42301]

Lots of good info here, Thanks