How to Stop Rust With POR 15
Sheetmetal Saver

By Jeff Smith
Photography: Jeff Smith

The war against rust never ends, but winning those individual battles just got easier. Hot rodders and resto artists fight rust on an almost daily basis.

Before your next alteration with oxidation, add POR 15 to your arsenal. In the early days of hot rodding, there wasn't much help besides primer, paint, or chrome. Worse yet, once the metal began its oxidation process, there was little you could do short of radical sheetmetal replacement surgery to prevent the metal's inexorable march toward further corrosion. But, the wonderful world of chemicals from Restomotive now includes a product by the name of POR 15.

The concept behind this stuff is fairly simple: create a product that when applied to sheetmetal will bond like it's been welded in place. The extremely strong bond prevents the corrosion process from continuing. In essence, POR 15 puts rust to sleep. While the chemical part of this equation would probably put all of us to sleep, the bottom line is that once it's applied correctly, POR 15 is like concrete. Unlike paints or other low-budget coatings, this stuff will prevent rust from coming back.

Perhaps the best news is that you don't have to have a degree in chemical engineering to use it, but it does demand you apply it properly. The key to success is a clean, dry surface on which the POR 15 chemicals can react and bond properly. Once it has dried, the topcoat protects from further corrosion and leaves a surface that, with the proper primer, can be painted easily .

Oftentimes, rust leaves deep pits or holes in the sheetmetal that must be filled as well. While typical bondo will work, Restomotive has developed a two-part epoxy putty that will also get the job done. In fact, once the putty has been mixed properly, the manufacturer claims it will cure even under water! We didn't put that claim to the test, but we did employ the putty to seal up a rusty '67 Camaro rear window area and trunk floor. While we could have performed sheetmetal replacement surgery, this Camaro wasn't bad enough to warrant that amount of work. We decided instead to treat the rusty metal with POR 15, and then repair the small rust holes with the epoxy putty.

Among its many products, the latest from Restomotive is a complete floorpan restoration kit offering a combination of the classic POR 15 chemicals along with a sizeable offering of the two-part epoxy putty and fiberglass mat material. The fiberglass mat is used to span small rust holes that are too large for the putty but don't necessarily need welding. The hole is covered with the fiberglass mat, which is then soaked in POR 15 paint and allowed to dry. This transforms the flexible fiberglass into a rock-solid chunk of rust-proof flooring. This is a permanent repair, though it's not advisable to consider this a fix for those Fred Flintstone floorpans where there's more open air than sheetmetal; those are more often lost causes.

The good news for musclecar restoration fanatics is that there are sheetmetal replacement panels for virtually every popular musclecar. But, there are times when a complete panel repop isn't really necessary. Some great spots for a POR 15 repair are the window channels around the windshield and rear glass, the area underneath the package tray, and any small spots of rust that are difficult to replace with welded panels.

The beauty of POR 15 is that once the rusted metal is properly treated, you can forget about rust ever appearing there again. If initial impressions are worth anything, even the first layer of the silver POR 15 looked like it would last forever. By the time we were finished, the trunk floor looked almost new. Our only regret was that we hadn't tried this stuff sooner!