Restoring That Gorgeous Gas Guzzler

What the classic auto enthusiast needs to know about asbestos

Motor-heads, tinkermen, grease-monkeys, wrench-spinners. By whatever nickname you call them, automotive hobbyists have one thing in common: they love working on cars, whether restoring an old classic, juicing up a hotrod, or keeping the family wheels running on a budget. Automotive repair and body work have been popular pastimes for generations of Americans, and while almost every hobby has had its share of inherent hazards in the last century, the unseen danger of exposure to the deadly toxin asbestos in vehicle repair work was not something most people thought of when they shined a droplight on a noisy valve head or sanded the putty in a bent fender. But it was there.

Asbestos is a naturally occurring mineral made up of microscopic fibers which are strong, heat resistant and inexpensive. These properties have led to its use in thousands of products and made it especially useful in the automotive industry. Asbestos fibers are so small that you cannot see them with the naked eye, making them easily ingested and extremely dangerous. When kicked up into the air from mixing, sanding, scraping or crushing the products in which they are imbedded, asbestos fibers can float freely and are easily breathed into your lungs. Besides asbestosis and lung cancer, asbestos exposure can cause the deadly cancer known as mesothelioma, for which there is no known cure. 

Most car enthusiasts know that asbestos has long been used in brake linings and clutch facings and, to a lesser degree, still is because, amazingly, asbestos is not banned in the United States. But there are plenty of other automotive products which contained asbestos back in the 1940s, 1950s, 1960s and 1970s. If you enjoyed wrenching on a car most weekends in your youth or if you channel Jay Leno in your love of restoring classic cars, here is what you need to know about some of the asbestos–containing products used in older vehicles:

Wiring

No matter whether the wiring in your car led to the headlights or to the ignition, it traveled through or around the engine compartment, an area consistently superheated by the motor whenever it was running. Typical plastic-coated wiring would have melted in minutes. Until this century vehicular wiring was coated with asbestos-cloth insulation, making it impervious to the high temperatures found under the hood. Old, worn-out wiring in classic or historic vehicles will fray when cut or manipulated and should be handled with care or not at all.

Hood Liners

As anyone knows who has watched heat waves radiate upward from an overheated car, the hood over the engine compartment gets very, very hot, even when the motor has not blown a gasket. Into the late 1970s, asbestos was woven into the fabric which lined most automobile hoods. These blankets prevented engine heat from causing paint on the hood to blister. These and other asbestos-lined heat seals throughout the engine compartment can become frayed after years of excessive heat and use, allowing the brittle fibers to crumble and become airborne.

Gaskets

While we’re on the subject of engine heat, there were few types of gasket material heavy-duty enough to withstand the extreme heat, pressure and friction caused by hot oil and gas coursing through an internal combustion engine, being constantly slammed by valves and pistons within the cylinder head. In addition to extreme temperatures and high pressure, such gaskets needed to be completely leak-proof and reliable for thousands of hours of use. Asbestos fibers, woven into the material used for engine gaskets, fit the endurance bill perfectly and were widely used in cars throughout the last century. 

Body Part Filler

Back in the day, most of us didn’t take our cars to a body shop when we had a little “run-in” with a curb or another vehicle. We went to the automotive store and purchased a can or tube of filler putty. With asbestos fiber’s supreme tensile strength, it was sometimes used as a component in body filler. Asbestos-containing automotive repair putty was introduced in 1955 as a mix of talc and plastic to which asbestos fiber was added. As a moist paste troweled into place on a vehicle’s fender or body, little dust was shed. But when dry, the filler was sanded smooth to match the contour of the dented part, and that’s when the microscopic dust particles flew.

Windshield Sealant

A chemical substance which remains pliable until exposed to the air, sealants harden into a solid, protecting the surface to which they are applied or providing a watertight seal. From 1950 to 1960, some tubes of sealant used to create a watertight bead around a newly installed windshield contained asbestos fibers for strength and durability. When moist, the sealant could not release its hazardous fibers. But once dried, if the caulking was sanded to make a smoother or more attractive appearance, toxic asbestos fibers were released.

Radiator Stopleak

Due to its inherent strength and resistance to heat, corrosive liquids and other caustic substances, asbestos was used widely in the automotive industry to prevent liquid penetration through holes or cracks in machinery. Have a leaky radiator? Chemical giants DuPont and Union Carbide, along with several other companies, manufactured substances used since 1945 as binders and plugs which could be poured or dumped into a cooling system or transmission and almost immediately plug a leak. How? Mixed with sodium silicate, dispersible gums, molasses and similar materials, asbestos fiber was perfect for adding bulk to a seal. Poured into a radiator, the heavy, fibrous substance settled into any crack or hole, forming a solid crust. This hardened plug created a watertight seal. In its liquid form, practically no exposure to asbestos fibers would occur. But the auto-mechanic or hobbyist restoring an old radiator would likely have chiseled or sanded the hardened plug away in order to weld a crack, thereby releasing the asbestos fibers into the air all around him. And the earliest stop-leak products came in powdered form.

Racing Leathers

While you might not be racing your own restored classic on a quarter-mile track, many early car enthusiasts did, and the fire-proof racing suits of old were made with asbestos fibers woven into the fabric. While the material was not “friable” when new, older suits became worn and brittle with time. And if, heaven forbid, the suits did come in contact with fire, the heavy fabric could fray and release asbestos fibers. Legendary film star Steve McQueen, who died of the deadly asbestos cancer mesothelioma, wore such fireproof suits for many years while racing cars as a hobby.

So, don’t hesitate to display your pride in showing off that perfectly restored classic car. But don’t expose yourself to the dangers of asbestos contamination and take a chance on cutting your life short in the in the process.