What’s that fog? It could be your dashboard cooking

If there is a great equalizer in cars, it is perhaps vinyl, the ubiquitous plastic in cheap subcompacts and luxury sedans.

Over the last decade, materials scientists have managed to make vinyl look expensive or at least they have convinced consumers that it looks expensive. That’s the best of vinyl.

The worst involves outgassing, which is not quite as vulgar as it sounds but is certainly a headache in the short term and destructive in the long run.

Car owners can see the results of outgassing on their windshield, particularly during the type of hot weather we’ve had lately. The outgassing forms a waxy film on the inside glass that distorts their visibility and is difficult to remove. They can also smell outgassing, which is part of the new car aroma.

Dashboards are generally made of polyvinyl chloride, that miracle plastic that was invented in the early 1920s and is now used in everything from water pipes to shower curtains. Unlike most materials, PVC can be rock hard or as flexible as cloth.

The way scientists do that is by adding plasticizers to the PVC, according to Shelby F. Thames, professor of polymer science and president of the University of Southern Mississippi. The plasticizers make the vinyl dashboard soft and allow manufacturers to shape it.

The problem comes as soon as the car is driven out of the factory and into the sunlight.

“Under intense heat and sunlight, there is a slight vaporization of those plasticizers,” Thames explained. “It would take years and years to lose the plasticizer at room temperature. But the rays of the sun are magnified as they go through the windshield, and the dashboard can get extremely hot, particularly on hot days like we have here in southern Mississippi.”

Of course, it gets toasty in Southern California as well. Plus the intense year-round sunlight here makes outgassing a persistent problem. In the high summer, dashboards can reach 200 degrees. As the plasticizers vaporize over years in the sun, the dashboard gets brittle. Eventually it will crack, exposing the foam core underneath and instantly reducing a car to clunker status.

Scientists are working on fixing the outgassing problem. Thames said they are trying to make plasticizers part of the molecular composition of PVC, rather than simply mixing them in. That would help improve the life of the product. Scientists are also working on sandwiching plastics with a thin layer of hard plastic on the surface of the dashboard that seals in the plasticizer. In some cases, manufacturers are using harder plastics in the interior that do not have plasticizers that can vaporize.

Automakers are greatly increasing the overall amount of plastic used in new vehicles, as well. Some high performance sports cars have body and frame parts made with fiber reinforced plastics, the same materials used in the newest jet aircraft.

Despite such advances, consumers still are contending with the outgassing problem. I have found that the waxy film seems to attract condensation, doubling the visibility problem. Wiping it with a rag only smears the waxy film. You can eliminate it with an aggressive soap or detergent, but preventing the problem is difficult, if not impossible. In some vehicles, these vinyl fogs develop almost every week in the summer.

It’s difficult, if not impossible, to prevent the loss of plasticizers. Thames said that various plastic treatments sold to consumers do nothing to seal in plasticizers. They may or may not help keep the vinyl soft, depending on the chemical composition of the dashboard and type of treatment used.

Mike Pennington, head of consumer relations for Maguiar’s Inc., which makes car waxes and polishes, said nobody makes a product that can prevent fogging from vinyl outgassing, but a treatment for vinyl interiors can help reduce damage by blocking ultraviolet rays that also degrade PVC.

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Pre-storage precautions

Question: I’m planning on storing my car for several months. Is this long enough to cause any problems?

Answer: I doubt a few months of storage will cause any problems, but you can still play it safe with a few precautions.

The biggest risk in storing a vehicle is that fluids will go bad, particularly gasoline. After a few months of storage, gasoline can deteriorate, affecting performance and eventually jeopardizing the fuel system, according to Tom Wicks, head of research and development for Gold Eagle, a manufacturer of Sta-bil fuel additive.

The problem is accelerated in hot weather, so if the vehicle is being stored in an unventilated garage in Riverside, you are asking for trouble in as little as two months. By contrast, in the cool winter months near the coast, the gasoline may be fine for up to six months.

It is always best to store a vehicle with a full tank of gasoline, which minimizes water condensation inside the fuel tank.

It also makes sense to store your vehicle with clean oil, which has a minimum of sludge and acid. An oil change before storage is a good idea.

I would check the air pressure on the tires. If a car is to be stored for a long time without being moved, it is a good idea to take the weight or at least some of the weight off the tires by putting the vehicle up on stands.

Newer cars packed with a lot of electronics gear have a fairly significant parasitic drain on the batteries. You might consider disconnecting the negative battery cable.

Finally, it’s a nice idea to have the car washed and store it inside a garage, out of the sunlight and dew.

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ralph.vartabedian@latimes.com