In the world of auto paints, there are basically two types of paint: acrylic and urethane. Acrylic paint was standard up until the 1960s, when urethane took over. Acrylic is water or oil-based while urethane is solvent-based.
Acrylic
Acrylic lacquer paint is the oldest type of auto paint, is the easiest to apply but lasts the least amount of time. Basically, it looks better than any other type of paint for a minute and then, once it sees much sunlight, begins chipping and fading. As a result, it’s popular among do-it-yourselfers who own classic and antique cars that they don’t pull out much. It’s perfect for getting your own beautiful relic ready for a classic car show, but ever since the 1960s, it’s been largely avoided by people painting general-use cars.
The other demographic that acrylic lacquer still has considerable benefits for are people learning how to paint their own general-use cars. Because it’s so much easier to apply–and easier on the environment–there is less damage to be done during trial-and-error. Damage, that is, both to the environment and to the new painter’s ego.
Acrylic enamel is oil-based and lasts much longer, usually between five and 10 years. Basically, it hardens after it’s applied, immediately creating a sort of shell that protects the finish. This is a big improvement over acrylic lacquer, but still cannot compete with urethane paint’s impressive durability.
Urethane
Urethane paint came to market in the 1960s and has largely taken over the auto paint world. It’s much harder to apply than acrylic, partly because it’s extremely toxic and thus requires special safety equipment and extra skill and care to work with. But once it’s on the car, it reflects UV rays much better than either type of acrylic. This is important as it further protects from the cosmetic damage that plagues its acrylic predecessors.
Just about every modern car leaves the factory with a urethane paint job, which is intended to last ten years or longer. You can pretty much bank on the probability that every 15-year-old car you pass that still looks just fine in its original paint is wearing a coat of urethane. In fact, most people agree that it looks good enough to make acrylic lacquer irrelevant altogether on a performance basis, even for owners of antique show cars.
How Long Does Paint Last?
If we’re talking about factory automotive paint, the short answer is ten years or longer. This wasn’t always true–it used to be half that or even less–but since the 1960s, automakers, restorers, and everyone painting cars has been using almost exclusively urethane paint, which lasts much longer–often, even longer than ten years.
Otherwise, in the case of acrylic paint, figure ten years or shorter. This is why it’s not used much anymore.