Feature article on composite aftermarket auto parts industry written
by Richard Stewart for Composites Technology magazine.
Composites Enable Low-Volume Shops
To Thrive In Auto Aftermarket Niche
Open-mold processes eliminate the need for expensive hard tooling in this fragmented market.
By Richard Stewart
Hundreds of small- to mid-size molders have carved out a
niche in the $152 billion U.S. automotive aftermarket parts
and accessories market, producing everything from spoilers,
hood scoops, running boards, and truck caps to replacement
parts and complete reproduction car bodies out of fiberglass
composites. Using mostly open-mold processes and soft
tooling, these shops focus on low-volume products that are
ignored by larger molders and automotive OEMs. Their
products enable vehicle owners to customize and accessorize
their cars, trucks and vans affordably.
Steve McNally, director of industry affairs of the Composites
Fabricators Association (CFA), feels that this segment is much
broader and more fragmented than anybody can get a handle
on. "We've never tracked composites in the automotive after-
market as a discrete market segment, but we know it exists
and it ranges all over the place, from two- and three-person
regional shops to much larger manufacturing operations with
formal distribution channels," he says.
"Many people who get into this business are car enthusiasts
who started making their own parts when they couldn't find
what they needed to fix up their classic cars." Most of the
production is hand layup and sprayup, notes McNally. "The
volume isn't there to invest in the hard tooling necessary for
closed molding," he observes. "Open molding is inexpensive
and it allows the flexibility needed for customization and
modification from one model year to the next."
ENJOYING STEADY GROWTH
Many of these composite aftermarket products turn up at the
annual trade-only show sponsored by the Specialty Equip-
ment Market Association (SEMA), whose 3,400 member
companies manufacture and distribute products for person-
alization, racing and performance, street rodding, classic
restoration and vehicle restyling. This segment of the auto-
motive aftermarket has been growing at an average of 8.5
percent a year for the past five years, according to SEMA.
One molder, Wings West (Newport Beach, Calif.), designs
and manufactures auto and truck aerodynamic styling
accessories, including over 600 different models and sizes
of rear deck spoilers of fiberglass composite material.
Starting with a wet layup in open molds, the spoilers are
made in halves, using fiberglass cloth and polyester resin.
After curing for about two hours, the halves are bonded
together to produce a spoiler.
Harwood Industries (Tyler, Texas) specializes in fiber-
glass body components, racing/performance equipment and
reproduction '32 Ford street rod bodies. Started as a one-
man shop in the mid-70s, Harwood now has over 80
employees. Best selling products include a bolt-on replace-
ment hood with an air scoop, which sells for $400. Last
year the company molded over 5,000 of the hoods in a
variety of sizes and styles, reports Joe Francis, sales
manager, who sees the product as "a relatively inexpensive
way to radically change the appearance of a car or truck."
The street rod bodies are offered in either a roadster model
for $6900 or 3-window coupe for $9500. The company is
planning to introduce a reproduction of a '32 Ford sedan-
delivery this fall. Buyers can build their own cars using the
composite bodies or have Harwood produce a turn-key
street rod with the buyer=s choice of powertrain and other
The body panels are hand laid up using glass/epoxy
composite molds. Gel coat is sprayed onto the molds,
followed by a barrier coat. Fiberglass mat, urethane honey-
comb and a blend of ortho resins completes the laminate.
After curing and trimming, the body panels are bonded
together with a methacrylate adhesive. The process takes a
week to complete one of the bodies.
TRUCK CAPS, BED COVERS
POPULAR FOR PICKUPS
Truck caps and bed covers have been a popular item for
pickup trucks for years, creating an industry that produces
600,000 to 700,000 units annually, according to Bob Keller,
vice president of Jason Industries (Elkhart, Ind.). The
company designs and manufactures caps and tonneau covers
of glass/vinyl ester composite. Jason is one of the top five
manufactures of truck covers, says Keller, building as many
as 25,000 truck caps a year in eight models to fit pickup
trucks going back as far as the '80s.
The fiberglass, cab-high series is the most popular selling
product. Using open composite molds, a primer gel coat is
sprayed on, followed by a primary layer of chopped fiberglass.
A layer of 2" thick honeycomb or corrugated board, depend-
ing on the model, is laid on next. That is covered with more
chopped glass, which is rolled to form a smooth interior
surface. Jason uses fiberglass roving from PPG (Pittsburgh,
Pa.) and resin from the CoREZYN Div. of Interplastic Corp.
(St. Paul, Minn.).
The amount of glass used depends on the style and model
of cap, but composite materials typically weigh 35 to 40 lb,
Keller says. Trimming is done with a water-jet, including
cutting out of windows and doorways. The surface is prep-
ped and painted with a base coat, followed by a clearcoat
According to Keller, the ratio of truck cover buyer to
truck owner has changed somewhat since the appearance
and subsequent popularity of the sport utility vehicle (SUV).
"Studies we did in the early '90s showed that 20 to 25 per-
cent of all pickup trucks sold were eventually covered with
something," he notes. "Today that number is reduced to
about 14 percent. But the pickup truck market is much
larger than it was then, so the total volume of covers hasn't
Another popular item for trucks and vans is the running
board. Aero-Tec, Inc. (Freemont, Neb.) molds steel-
reinforced fiberglass running boards for SUVs and vans and
also produces truck steps for pickups -- about 250 different
sizes and styles in all to fit most makes and models, relates
Miles McMahill, vice president. Composite molds, made
in-house using a tooling resin from Alpha/Owens Corning
and chopped glass, are stacked floor to ceiling in the
The products are molded in a novel assembly-line process.
Molds are placed on rolling carts that are pulled along by an
in-floor tow line. As many as 40 carts can be linked together
in a chain that loops through the plant, constantly moving until
each product reachs the final stages of manufacturing,
At the front end of the line, a gel coat is sprayed on,
followed by a barrier coat, which helps eliminate air pockets
and solves cosmetic problems. Then chopped glass is
sprayed up in a two-step process. A layer of chopped fibers,
between 1/16" and 1/8" deep, is applied and rolled to work
out air trapped in the resin and eliminate voids. Next a length
of 16-gauge steel tubing is laid on top of the glass. A second
coating of glass spray-up encases the steel, for a total depth
of 3/16" or more, explains Bob Church, who supervises the
gel coating and laminating operations. "We use utility knives
to do a wet trim; The fuzzies are ground off, and everything
is buffed," says Church, a 40-year veteran of the composites
Not everyone making aftermarket parts from composites
uses open mold processing. The best selling product of
American Products Co. (Corona, Calif.) is an RTM'd roll
pan, which is an appearance product that replaces the rear
bumper of a truck to produce smoother body lines, relates
Brian Horowitz, owner of the company that does about
$100,000 a month in RTM'd parts and accessories.
"All the products we make are for aero enhancement. They
have no real function other than to allow people to personalize
their vehicles and give them a custom look," he notes. The
company produces about 50 roll pans a day, using a resin
that takes four hours to cure. Other composite products
include replacement instrument panels, grille shells, wiper
cowls and tonneau covers.
COLLISION PARTS LARGE
Polywheels Manufacturing, Ltd. (Oakville, Ontario) produces
a wide range of compression molded automotive OEM parts,
along with a line of header panels for aftermarket applications.
A header panel, which holds the headlights and grille, is
commonly damaged in front-end collisions and must be
replaced. Polywheels offers 42 different models of SMC
header panels, for Ford, GM and Chrysler products, going
back as far as 1978, relates Sean Milligan, vice president.
The company's annual volume of this product for the after-
market is between 80,000 to 100,000 units.
Budd Plastics Division (Troy, Mich.) is active in the service
parts segment of the aftermarket as an offshoot of the original
SMC production parts it manufactures for vehicle manufacturers.
Service parts, used by body shops to make repairs, total about
10 percent of the volume of Budd's production parts, according
to Mike Dorney, manager of North American sales and market-
ing and vice chairman of the Automotive Composites Alliance.
The Plastics Division has been experiencing 5-10 percent growth
of its thermoset composite products each year for the past 15
years, and the forecast is for average growth slightly higher than
that over the next five years, reports Dorney. Budd produces
composite decklids, rear filler and front end panels, fenders,
hoods, doors and other components. Contracts for service parts
are renewed with OEMs on a year-to-year basis, and molds are
typically kept from three to seven years.
The Delphi Chassis Systems Division (Dayton, Ohio) of
Delphi Automotive Systems manufactures composite leaf springs
for commercial trucks and trailers, both as original production
and aftermarket parts. The single-leaf fiberglass/epoxy springs,
known as Liteflex(TM), offer weight and durability advantages
over steel, according to Delphi. Weighing about a third as much
as steel springs, they can reduce the tare weight, thereby
increasing the legal payload, of a tractor-trailer by as much as
800 lb when retrofitted to the five axles of a typical combination
So profitable is the automotive aftermarket that traditional
aftermarket manufacturers are facing increased competition from
upper tier suppliers, says John McElroy, long-time automotive
industry observer and journalist. Speaking in May at the Global
Automotive Aftermarket Symposium, sponsored by half a dozen
associations representing aftermarket parts suppliers, McElroy
characterized the new players as multi-billion dollar, multi-national
corporations with incredible resources.
"These suppliers see the aftermarket as an opportunity to raise
their profit margins in the face of relentless pressure from OEMs
to cut costs," he says. "The aftermarket is viewed as being counter-
cyclic," he adds, noting that during a recession, consumers often
opt to maintain their current vehicles rather than buy new ones.
"There is great opportunity in the aftermarket," especially in the
area that McElroy calls "mass customization," the practice of
accessorizing and customizing vehicles.
According to SEMA, the products offered to consumers by
aftermarket manufacturers are "the medium consumers use to
express their individuality, at least when it comes to what and
how they drive." It calls the 1999 SEMA Show, scheduled
for Nov. 2-5 in Las Vegas, "the sexiest venue in the world to
experience the driving force behind a planet of people seeking
better value for their drive time."