Spend some time browsing through an auto parts store or the automotive aisle of your local big-box retailer, and you'll inevitably come across various filler products. These products claim to offer a quick fix for dents and other issues, but they suffer from many of the same pitfalls as other do-it-yourself body repair methods. Unfortunately, the real-world results are rarely acceptable.

If you're planning to repair your car's exterior using one of these products, consider these three reasons you may want to leave the job to a professional body shop instead.

1. Preparation Is Critical

One fact constantly bubbles to the surface when talking about any part of automotive exterior work: preparation is critical. Your skills at using automotive paint, body filler, or any other repair product don't matter nearly as much as your surface preparation skills. Incorrectly preparing a surface can lead to repairs that look poor and, even worse, may fail over time.

Using fiberglass filler is no different. An incorrectly prepared surface won't allow the filler to bond properly, which may lead to numerous problems in the future. Common issues include cracking, peeling, and even the entire repair failing and dropping off the car. Professional body shops know how to handle surface preparation correctly, ensuring a durable and great-looking repair.

2. It's Not Appropriate for Many Repairs

While filler has its place (even in professional auto body repair), it's often inappropriate for certain repairs. For example, the filler will bond poorly to surfaces with rust, and it may not provide a long-lasting repair if you apply it too thickly. Likewise, some parts of your car may get too warm or become exposed to fluids that can damage the filler and cause it to fail over time.

Professionals understand these limitations and use filler only when necessary and only for repairs where appropriate. If you don't have the experience and knowledge necessary to make these determinations, your "quick fix" can easily lead to a result that looks even worse than the original damage.

3. There Are Better Options

There are far better options for repair in many cases than using fiberglass filler. Paintless dent removal (PDR) is one such alternative. PDR can typically provide a far more professional final result if your car has dents or dings that haven't damaged the paint or metal. Even better, these repairs are permanent so that they won't reduce your vehicle's long-term value or appearance.

Filler isn't always the wrong choice, but it's critical to use it sparingly and to correctly prepare the surface before beginning your application. In many cases, trying to use these products as a quick do-it-yourself fix will only lead to problems over the long run.

Contact an auto body shop near you for more information about auto body repair.