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Factory-Fresh: How Fiberglass Bodies Are Built

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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.

These complete FFR Kits are ready to ship out to anxious customers. Each FFR body is hand-built and then precision machined to exacting tolerances.

These complete FFR Kits are ready to ship out to anxious customers. Each FFR body is hand-built and then precision machined to exacting tolerances.

In the master craftmen’s R&D studio, a master plug is being designed for mold making. This is the exact size and shape of the final product. Molds will be taken from this plug to create the master molds to reproduce parts.

In the master craftmen’s R&D studio, a master plug is being designed for mold making. This is the exact size and shape of the final product. Molds will be taken from this plug to create the master molds to reproduce parts.

The plugs are created using various materials, including wood, fiberglass, and body filler.

The plugs are created using various materials, including wood, fiberglass, and body filler.

This mold has been prepped for gel coat. This particular mold is for a fender.

This mold has been prepped for gel coat. This particular mold is for a fender.

Once sprayed with gel coat, the mold must sit for 4 hours for the gel coat to cure. Gel coat is a very hard and durable. It also seals the fiberglass from UV rays and provides a smooth surface so that the fiberglass weave does not show through.

Once sprayed with gel coat, the mold must sit for 4 hours for the gel coat to cure. Gel coat is a very hard and durable. It also seals the fiberglass from UV rays and provides a smooth surface so that the fiberglass weave does not show through.

A cad program is used to tell the cutting table how to cut the precise patterns for the molds. Each mold uses specific patterns for minimal waste and faster lay-up time.

A cad program is used to tell the cutting table how to cut the precise patterns for the molds. Each mold uses specific patterns for minimal waste and faster lay-up time.

This Eastman cutting table makes it easy to create lots of patterns at one time. Large rolls of fiberglass await their turn under the knife.

This Eastman cutting table makes it easy to create lots of patterns at one time. Large rolls of fiberglass await their turn under the knife.

After the pieces are cut, they are stacked up on shelves. The FFR assembly craftsmen count out each sheet before taking the correct number to the mold for layup.

After the pieces are cut, they are stacked up on shelves. The FFR assembly craftsmen count out each sheet before taking the correct number to the mold for layup.

The fiberglass patterns are laid into the molds by hand with a light coat of resin. Some patterns feature cuts for folding so that the finished panel is of a uniform thickness and shape.

The fiberglass patterns are laid into the molds by hand with a light coat of resin. Some patterns feature cuts for folding so that the finished panel is of a uniform thickness and shape.

After each layer of mat goes down, the craftsmen apply resin over the fiberglass and smooth all the bubbles out with a roller.

After each layer of mat goes down, the craftsmen apply resin over the fiberglass and smooth all the bubbles out with a roller.

The finished pieces take about 4 hours to harden. Properly mixed resin is the key to making quality fiberglass parts.

The finished pieces take about 4 hours to harden. Properly mixed resin is the key to making quality fiberglass parts.

Some pieces get trimmed by hand to take off excess material before moving on to the six-axis CNC machine.

Some pieces get trimmed by hand to take off excess material before moving on to the six-axis CNC machine.

The six-axis cnc router precision cuts all the edges as well as all the holes for handles, hinges and alignment.

The six-axis cnc router precision cuts all the edges as well as all the holes for handles, hinges and alignment.

 The Six-axis CNC router is located in an airtight room which seals off the fiberglass dust and keeps the shop clean. Fiberglass is itchy after all.

The Six-axis CNC router is located in an airtight room which seals off the fiberglass dust and keeps the shop clean. Fiberglass is itchy after all.

The CNC mounts use suction cups to hold the pieces in place during the trimming process.

The CNC mounts use suction cups to hold the pieces in place during the trimming process.

This finished door has all the correct holes for assembly. This piece is ready to go.

This finished door has all the correct holes for assembly. This piece is ready to go.

Sources:

Factory Five Racing

http://www.factoryfive.com/

About Jefferson Bryant (201 Articles)
A life-long gearhead, Street Tech Magazine founder and editor Jefferson Bryant spends more time in the shop than anywhere else. His career began in the car audio industry as a shop manager, eventually working his way into a position at Rockford Fosgate as a product designer. In 2003, he began writing tech articles for magazines, and has been working as an automotive journalist ever since. His work has been featured in Car Craft, Hot Rod, Rod & Custom, Truckin’, Mopar Muscle, and many more. Jefferson has also written 5 books and produced countless videos. Jefferson operates Red Dirt Rodz, his personal garage studio, where all of his magazine articles and tech videos are produced. You can follow Jefferson on Facebook (Jefferson Bryant), Twitter (71Buickfreak), and YouTube (RedDirtRodz).

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