Supercar Made by Composite Hand Lay-Up

Lucra’s LC470 is one of the lowest-priced full-carbon fiber vehicles on the market.

Carbon fiber has long been regarded as an automotive application that many want, but few can afford. A majority of full-carbon cars will cost you upwards of $200,000, but one small manufacturer offers is trumping the trend with a model at half that cost.

Lucra’s LC470 is an automotive street racer comprised of 100 percent carbon fiber. The small company manufactures around 50 of these cars per year. The project, originally developed in 2006, began when Lucra saw a space in the market for a reasonably-priced supercar.

“When we first developed the car, fiberglass was the suggested material to use because there was this perception that due to cost, carbon fiber wasn’t an option,” says Project Manager Eric Shimp. Lucra felt that because tools like CNC machines have become more accessible to smaller companies, the barriers to entry weren’t too prohibitive. “It is a little more expensive, but as far as the perception to the buyer, full carbon really turns them on,” says Shimp.

Hand Lay-up versus Prepreg

The composite work itself is done through Carbon by Design. Though the company does a heavy amount of aerospace work these days, its roots are in automotive and John Schauer, who founded the company, says it’s become proficient at various composite manufacturing techniques.

Chief among these is simply being able to wet lay-up carbon fiber applications with no pressure intensifiers. “Most people that build carbon (especially out of Asia) use a polyester resin with no gel coat because they can’t get the air bubbles out. So they spray about six coats of automotive clear, sand it down and polish it to address that issue. But that doesn’t really do anything. It makes it look good when the customer gets it, but six months later, it’s faded and brittle,” says Schauer.

Carbon by Design sprays a marine-grade UV-protected gel coat in the mold. It then lays the fabric and the resin behind that, which the company says results in an air bubble-free surface—a technique Schauer calls a lost art. “We really feel the basis of all lamination starts by doing it with your hands. If you’re a good hand laminator, you’ll be good at infusion as soon as you learn it. If you’re good at that, you’ll be good at RTM, and then you’ll be good at prepreg. It’s just a learning curve from beginning to end. But mold making and hand layup is extremely important in order to create a bubble-free surface,” he says.

According to Schauer, hand lay-up has largely fallen out of fashion to make way for prepreg. “It’s certainly a quicker process; you just cut it and lay it down, and put a vacuum bag on it,” he says. Schauer also notes the degree of difficulty as a reason why prepreg is preferred for manufacturing. “You can train someone to use prepreg in a month, but it probably takes six months to train someone in hand lay-up,” he notes.

The process is so difficult because a worker is essentially doing it blind. “When you lay carbon on a clear gel coated mold, you can’t see the air bubbles because they’re under the carbon. So you have to go by feel, and it’s hard to feel every pinpoint air bubble in a part the size of a hood,” he says.

Market Forces at Work

One of the biggest reasons the LC470’s cost is much lower has to do with market forces. “For automakers such as Ferrari and Lamborghini, you’re paying for a name,” says Schauer. “I’m not knocking those cars, they’re great. But, they have a specific business model and it’s far different from this one. They set and create demand, and produce only as many vehicles as they see fit,” he adds.

Schauer thinks manufacturing with carbon fiber will get less expensive over time and that automotive will mirror developments in aerospace. “Right now, the aerospace industry is converting to composites to the point where everything could be made of composites in 20 to 30 years. The automotive industry will follow a similar path. Everyone wants to use carbon fiber, but they just don’t like the cost. When you have the R&D and money behind you, there will be ways to figure out how to do it,” he says.

According to Shimp, it’s the smaller companies that will help galvanize innovation and development. “Smaller companies are more versatile, and can take advantage of material changes and trends more quickly. Larger companies use tooling and assembly lines for longer periods of time, so you can’t change those as quickly,” he says. “Larger firms are also more sensitive to small changes in their bottom line in such areas as pricing. We just want to build the best product, so we’re not as sensitive to that.”

Tags: Auto, composites, Lucra LC470, news