Top 6 Paint And Body Questions - It Ain't Just Paint

3.) Glue It!

Question: With structural adhesive widely used by auto manufacturers to attach body panels on today's vehicles, is it an option when installing new panels on vintage Pontiacs. Does it offer any advantages or disadvantages over traditional welding?

Answer: General Motors began using structural adhesive on vehicles in the early '90s. Anyone familiar with Firebird models produced during that time can testify to its benefit. In addition to normal welding, the body panels of these models were literally "glued" together, significantly increasing body rigidity and subsequently improving overall build quality.

Since so many new vehicles are built with composite panels, structural adhesive has replaced welding in a number of areas. In many instances, it is used to bond metal panels, too. Wanting to know if structural adhesive is compatible with vintage Pontiacs, we contacted Melvin Benzaquen of Classic Restorations in Pine Island, New York. You may recognize Benzaquen's name from his longtime relationship with HPP as a contributor, but anyone who has seen examples of his work knows that his credentials speak for themselves.

Benzaquen tells HPP that using two-part, epoxy-based structural adhesive to install new body panels has a number of advantages. "We've used it for years without any negative effects. It's widely employed by auto manufacturers today, and '06 crash standards far exceed those of 20 years ago. So that says something about it. But it's also less hazardous than welding, and there is no initial cash outlay to purchase a high-quality welder, welding wire, and gas," he says.

Unlike welding, which can require a lengthy learning process, using structural adhesive is fairly straightforward. It has made fitting body panels easier for restorers, too. "It gives us a little time to adjust the panel while the epoxy sets," says Benzaquen. "And since we aren't heating the metal by welding, there is no metal shrinkage or warping to contend with. That means there is far less grinding to clean welds and smooth body joints, which can translate into cost savings for the customer."

4.) Vintage Sheen

Question: What products available today most closely replicate a Pontiac's original finish, and is durability compromised in any way?

Answer: Anyone who has purchased a vintage Pontiac when new knows that very few vehicles left the factory sporting a mirror-like finish that was blemish-free or without an area of sparse coverage. That means replicating these flaws during a restoration could be considered correct. But since points are not deducted for clearcoated or wet-sanded finishes at points-judged Pontiac gatherings, many owners forego the original appearance and opt for basecoat/clearcoat to give their Pontiac as much luster as possible.

Dave Chalek of Chalek's Auto Body in Bellevue, Nebraska, has been restoring vehicles in his shop since 1989. He learned the technique of flawless paint application working alongside his dad, Bob Sr., from a young age. Anyone who has seen the family's work knows how seriously they take the art of paint and bodywork.

Chalek says that the original finish found on most vintage Pontiacs was lacquer-based. While the availability of lacquer is severely limited today, he feels that the removal of lead from it in recent years has also compromised its durability. "Single-stage urethane with minimal sanding and/or buffing most closely resemble the lacquer finish applied by Pontiac," says Chalek.

Like lacquer, single-stage urethane metallic colors can be difficult to work with. "They can streak or leave blotches," Chalek says. He went on to say that this was a fairly common occurrence when the paint level in the siphon can of the older siphon-fed paint guns got low. But with today's gravity-fed high-volume/low-pressure (HVLP) guns, the situation has greatly improved.

"We prefer to use basecoat/clearcoat when restoring vehicles," Chalek says. "It provides a high gloss and gives the finish lots of depth. But base/clear doesn't necessarily offer additional durability over a single-stage finish." It does, however, have advantages when spot repairs are required. "Unlike a single-stage where an entire panel must be painted, we can usually apply base color to the blemish and then blend the clear into the panel, making the repair practically undetectable," he adds.

Chalek notes that modern finishes are very durable and not nearly as vulnerable to the elements as the originals. They are also virtually maintenance free. After the initial wet-sanding and buffing, they require normal polishing to maintain their luster once the 90-day curing period has elapsed. Unlike a lacquer finish, however, scratches must be removed using a high-speed machine buffer.