Carbon Fiber Bodywork

While I was spraying the PVA, I was setting up for the layup, starting with the vacuum bag. The bagging material I have is a tube, which simplifies sealing

I got in the groove, and I forgot to take a few pics while doing the layup. So here is a pic after I placed 4 layers of fiberglass cloth and the perforated release film.

I coated the inside of the mold with resin 1st, then began laying the cloth, adding more resin as needed. I spread the resin and worked it in with a bondo spreader. I purposely left some air pockets in the corners to see if the vacuum would make them go away

I got everything bagged up and plugged in the pump. After about a minute it looked like this:

You can already see the excess resin coming through the perforated release film and soaking into the breather material

After 5 minutes:

I doesn't take long to suck out the excess resin. On the next layup I will make more of an effort to make some pleats in the bagging film to allow it to more tightly fit against the laminate.

Of important note is the fiberglass cloth I'm using. It is a fairly heavy weave, and DOES NOT conform well to the compound curves of the mold surface. If I were to use fiberglass in a final product, I would source a much lighter/thinner fabric that would conform. It makes all the difference if you don't want air pockets or cavities. The cloth you use must conform to the surface of the mold by itself (or very close to it), the vacuum pump won't do this for you...just FYI

2 hours later, I stripped the bag, bleeder and perforated release film:

Wait, whats that dark patch in the middle???

I am very happy to report that the laminate de-molded quite easily :woohoo: :woohoo:

Oh, and I threw in a scrap piece of carbon, just for kicks. There is a greenish tint to the laminate. Part of that is the cured color of the polyester resin I'm using, the other part is the green PVA still coating the laminate

With the PVA removed (it just peels off) the part looks something like this :pinch:

Those of you with keen powers of observation will note that this sidecover is incomplete. Due to the difficulty I encountered in getting the heavy weight fiberglass to conform to the mold, I decided not to waste my time with the tighter radius of the mounting points

From the front

There are small imperfections in my mold, and if I were to produce parts that were not going to be painted at all, I would do a 1500 grit sand and spray with an automotive polyurethane clear coat to protect the part. What I've read about epoxy resins is that they do not contain any UV resistance, and exposure to UV radiation (the sun) casues yellowing of the epoxy. Therefore, anything made with epoxy resin and exposed to the sun needs additional protection.

Very cool looking. I've never had the patience for that detailed of composite work. Kudos for taking the time to keep working it out to get it where you want it.

Thanks kawiconvert, but I'm still a ways from getting it the way I want. I hope to get the composite laminating schedule worked out on this mold, then avoid my known mold mistakes on subsequent molds

Now that I know the laminate isn't going to stick in the mold, I need to figure out how to incorporate a core material to add rigidity and cross sectional area but without the weight or cost of a solid cloth part. I experimented with closed cell foam and coremat earlier. Coremat was easier to work with on a flat surface, but at the time of my experiments I didn't know the proper way to do a foam core layup. I was trying to do a single layup with all the layers, but I have since learned that this is not the proper way. You laminate a few ply against the mold and cure it. THEN you laminate the core material and final cloth layers in a secondary layup. It is done this way so that a proper filet can be spread along the edge of the core material to ease the transition of the rear cloth layers over the edge of the core material (if readers recall I had trouble with the fiberglass not properly conforming over the edge of the foam and leaving air pockets). The filet is made of some laminating resin (whatever you're using) mixed with a low density filler such as microspheres (super tiny hollow glass balls). It makes an adhesive putty that stays where you put it. So that's what I'm going to try here; a 2 part layup using carbon and the 2mm foam core material. It took me a while to fit the foam core to the mold. Here is work in progress

Using a $7 H.F. heat gun a razor blade and some sissors, I cut the foam and molded it into the mold. I decided not to try and work the foam around mounting points, as I figured this would just invite trouble. I already make plenty of that on my own. After painstakingly trimming the foam little by little to get it perfect, I started hacking it so it was a simple as possible. The end result:

Not super pretty, but it will do it's intended job without making any void inducing areas for me to worry about. After I was happy with the design, I made a template out of card stock for ease of reproduction