How to Stop Rust With POR 15
As seen in: Sheetmetal Saver By Jeff Smith Photography by Jeff Smith
Before	After
This is the POR 15 trunk floor kit. The critical components are the cleaner/degreaser and the follow-up zinc phosphate metal treatment that prepares the rusty metal for the POR 15 paint. POR 15 includes a silver base paint followed by the original black. The kit also includes a black topcoat, a two-part epoxy putty for small holes, and even a fiberglass mat for covering larger areas. These chemicals are somewhat harsh, so also included are several pairs of latex gloves, a mask, several paint brushes, and a container of solvent.
Because we’re such conscientious hot rodders, we decided to take the time to read the directions. As with painting, surface preparation is the key to success. We scraped, chiseled, and wire-brushed the surface to remove all the loose rust and then vacuumed the trunk floor clean.
Then it was time for the first step: POR-15’s heavy grease and oil remover. This cleaner is reserved for very greasy surfaces, but we felt it couldn’t hurt. We used gloves and the supplied dust mask since many of these chemicals are hazardous. We followed the degreasing step with a fresh water rinse, which we allowed to dry before moving to the next step.
This prep was followed by a zinc phosphate coating that we applied with a brush and allowed to sit on the surface 15 – 20 minutes then rinsed with water and left overnight to completely dry. If you try to rush the process and the surface is not completely dry, it’s possible the hard coating will not adhere properly and it will eventually lift off.
We poured some of the solvent into another plastic cup to clean the paint brush. It only took about an hour for that nasty solvent to dissolve the plastic cup! Obviously, these are materials that should be treated with respect. Use containers that will be disposed of properly. A tin coffee can is probably best.
To finish off this trunk resto, we added a rear deck lid spoiler from Classic Auto Parts to replace the missing one that allowed water to enter the trunk. The rear spoiler (PN F6768-12181-A) bolted on with no hassles. We also added a new trunk lock from Classic (PN F67-10266-LK).
The next day, we returned to the trunk and applied the silver base coat that seals the rust. As per the directions, we ladled the paint into a disposable plastic cup and resealed the can, being careful not to spill paint onto the lid sealing surface. We also used plastic wrap under the lid. It took surprisingly little paint to coat most of the trunk floor.
With the trunk floor now finished off with the silver portion of the POR 15, it was time for the black coating. We merely brushed the paint on, just like the silver coating. When coating larger areas, you can spray POR 15 with a gun, but be sure to wear a mask and carefully clean every orifice of the spray gun before the paint dries. POR 15 cures by using the humidity in the air to aid the drying process. POR-15 also warns that if either the silver or black coatings dry on your skin, they will only come off with time. We then finished the trunk with Plasticoat’s spray-can splatter paint and new weatherstripping from A&M SoffSeal to keep our new trunk clean and dry.
This same Camaro needed a tune-up undern the back window to keep water out of the trunk. As you can see, there were several rust holes but nothing bad enough to warrant replacing the panel. We performed the same cleaning and degreasing operations as on the trunk,in preparation for the silver POR 15 coating.
Here’s the rear window ledge with the rust cured with the POR 15 silver paint.
Next, we mixed up two equal amounts of the POR 15 putty, making sure to mix it thoroughly.
We then applied the putty with our fingers and smoothed it with a small amount of water. The following day, after the putty had cured, we easily sanded the areas smooth with a Dremel tool and a tiny sanding drum. The putty dries absolutely rock hard, yet it sands very easily. This is great stuff.
The final black topcoat will only partially show after the rear window is reinstalled. This coating will not fade in the sun and will look good for years. The whole process took only a few hours of actual work and is far less expensive than sheetmetal surgery.

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.

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, POR-15 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 POR-15 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!