Factory-Fresh: How Fiberglass Bodies Are Built
If you’re not familiar with factory five racing get ready to be impressed. Factory Five was founded in 1995 and is the world’s largest manufacturer of component car kits. Although they are the best and the biggest, they are a company like no other. They will tell you themselves they are more like a family. Having spent some time with these guys we can tell you, it’s true. These are car guys doing what they love. Having recently built a factory five cobra, we know firsthand what it takes to put one of these cars together. We recently had the opportunity to tour their factory in Wareham, Massachusetts, and learned just how these cars are designed and produced.
One of the most interesting things is the hand-laid process used to create the components of the bodies. Even though the process is a fairly simple, hands-on process of producing the body panels, hood and decklid, the Factory Five Racing workers are not just laborers, they are precision craftsmen, as you will see in the next few pages.
The first step in the process is to design what master craftsman John Crawl called the plug. This is the plug which John explained as “the master shape which will be used to make the molds that will then produce a lot of parts.” John explained that he used whatever tools and materials were available to create the exact shape given to him by the design team. These plugs are then used to create molds for the various components of the car. The final finish of the parts must be 100% perfect, as the replication process will show every flaw, and even reproduces the sheen of the master plug. 500-grit sanding scratches will show up, the master plug finish is critical to reproducing quality fiberglass parts.
Once the design is complete, the plug is then framed up into sections for the molds. You can’t make a one-piece mold of a complex shape due to the various angles and draft issues that can lock the pieces into the mold itself, they have to be made in sections like a jigsaw puzzle. The body is formed as one unit inside a series of mold panels that bolt together. Once the sections are created, the new molds are taken down to the shaping room.
Before any fiberglass goes into the molds, the mold must be prepped. The fiberglass will stick to the mold if it is not waxed and sprayed with a release agent. There are several release agents available, but the most common is PVA, or Poly Vinyl Alcohol. This agent starts out as a liquid, and then dry, forms a single sheets that peels off the waxed mold surface. Once the PVA is dry, gel coat is sprayed into the molds through a chopper (HVLP) gun. These specialty guns perform two functions simultaneously- One side sprays the gel coat, while the other side shoots out small cut threads of fiberglass. The guns are adjustable for short or longer strands. The gel coat is applied first without fiberglass chop; this yields the smooth surface of the finished surface. The red gel coat dries in about four hours.
Next, an Eastman cutting machine cuts detailed patterns out of fiberglass matting. This CNC cutting table cuts the patterns to the precise measurements needed for each mold. FFR craftsmen then place the fiberglass patterns into the molds along with polyester resin. They use special rolling tools to remove bubbles and create a smooth surface. If the bubbles are not removed, the air pockets create weak spots in the panel. These can result in flexing panels and soft spots in the finished surface. One layer of fiberglass is only as strong as the one it is laid over. The fiberglass layer is added on top of the gel coat to create an easier smoother surface for sanding and painting later. Once the fiberglass layer has cured, the components are popped out of the molds. At this point, the basic part is made, but not ready for fitment. The fiberglass process leaves quite a bit of flashing around the edges, time for a haircut.
Each panel is mounted to a special clamping mold on a six-axis CNC machine. This computer-controlled machine is programmed not only to trim the edges of the pieces precisely; but also, to cut holes for hinges, door handles, and other parts of the car that require specific locations. This automated process ensures 100% accuracy and faster production times than human-powered operations. Each piece comes out of the six axis machine ready to go for vehicle fitment.
Fiberglass bodied cars are quite popular and for good reason. The design possibilities are endless, vehicle weight can be drastically reduced, and perhaps most of all, make once unobtainable vehicle designs available to the average gearhead. And that is what hot rodding is all about.
Factory Five Racing
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