Preparing For Powder Coating: How To Ensure A Long-Lasting Finish For Your Classic Car Parts

by Claude Walters

Powder coating can be a great way to keep parts on your classic automobile from rusting or deteriorating. The process of powder coating electrostatically covers metal parts with a thin layer of a plastic or polymer that is then heat-cured and hardened. The powder is not in liquid form so it produces a thinner, more even and more durable finish than a traditional paint.

Ideal for protecting metals, powder coating has gained popularity as a way to keep parts on both classic and newer vehicles from getting surface damage and rust. It's especially common to see powder coatings sprayed into truck beds as a protective liner, for example. But classic car restoration hobbyists can use this technique to make the vehicles they work on stronger and ready to roll for several more decades.

Surface preparation is key.

The most important thing to know about powder coating is that the more perfect the base that you start with, the better the process will work. This means that all parts to be coated should be clean and free of oil and rust.

Phosphate-based cleaners are most commonly recommended for treating auto parts. Iron phosphate and zinc phosphate are both used in the "phosphating" pre-treatment process.

The acidic phosphates work by creating a chemical reaction when they hit the metal part. This works to combine the metal with the iron or zinc in the phosphate to form a smooth and strong top layer, which then allows the powder coating to stick better.

Be cautious when working with these corrosive cleaners and follow proper procedures for disposing of the used cleaning material. Your powder coating shop may take care of this step for you as part of their process.

Applying powder coatings.

Most professionals use a gun applicator to apply the powder coating. This gun, sometimes called a corona gun, creates an electrostatic charge in the powder. The charge then helps the powder to evenly stick to the metal part until it is heat-treated to harden the finish.

The heat-treating process requires a source of heat up to about 400 degrees. During this curing, the powder coating forms a bond with the metal and becomes impossible to remove. This is part of the reason why powder coatings are so durable.

You can choose from a variety of colors for the powder coating. In some applications, you can also paint over the coating and it will adhere better than to the metal alone.

Parts that often have powder coatings applied include frames, axle housings, springs and other parts that get the most road wear or would otherwise be difficult or impossible to cover with paint. For further assistance, contact professionals, such as those from Metal Tech Of Murfreesboro.