Navy Formula 117

1957 Austin-Healey 100-6 Chassis After Navy Formula 117 Pre-treatment

Pictured above is the chassis of my 1957 Austin-Healey 100-6 shortly after applying Navy Formula 117. I had written the article below about my experience using the product, and I thought I'd bring it back to life on this website because I felt it might be beneficial to anyone currently planning to perform a complete frame off automobile restoration. I will most likely use this product again someday....

Navy Formula 117 is a zinc rich pre-treatment that was formulated years ago for the United States Navy. It is intended to be applied onto clean surfaces such as bare aluminum, steel, or other surfaces that may be prone to having adhesion problems, because Navy Formula 117 has superb adhesion qualities. For bare steel, I feel it is the next best thing to galvanizing. After all, it was initially developed for use on steel that is subjected to salty sea water. I have lived my life in an area termed as the rust belt. This term partly refers to a region that deals with the affects of salt applied to roads to melt ice and snow during the winter months....resulting in rusty vehicles.

There were many little nooks and crannies within the above complex chassis structure, and the pre-treatment was chosen to help treat and protect the bare metal. Whether it is microscopic rust that cannot be seen by the naked eye, crimped or welded seams that often hides oxidation, or aluminum attached to steel (galvanic reaction), they can all lead to rust that will continually progress even after top coating with your favorite product. With proper preparation and coatings, this chassis is expected to be rust free for many, many years to come.

The chassis was sandblasted to bare metal, and without delay, it was then cleaned thoroughly with a proper [non H2O] cleaner just prior to a thorough spray of Formula 117 pre-treatment. Once the treatment dried to the touch (usually within 30 minutes), the surface was ready for other coatings. For best adhesion, the next coating needs to be applied at this time.

I chose to go with PPG DP40 epoxy primer as the second coating. The third coating was PPG Delstar Polyurethane Acrylic Enamel formulated to match the original color for Austin-Healey Colorado Red. The remaining body panels were also coated with the same epoxy primer over bare metal, but then topped with a PPG sandable filler primer before many hours of preparations (color sanding, etc...) to achieve a near perfect surface, and then top coated with the same PPG polyurethane color coat as used for the chassis. Other than the initial Navy Formula 117, it is advisable to use only products that are intended to be used together. In my case, I used all PPG products for this car.

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More About Navy Formula 117

Navy Formula 117 is a zinc rich pre-treatment that leaves a bright green opaque finish as pictured above. It is intended for use on clean metal surfaces as a pre-treatment, applied prior to the application of primers and paints. It is especially useful on hard to adhere to surfaces such as aluminum, stainless and galvanized steel, and is an excellent choice for use on carbon steel, such as those used on automobiles. Once the treatment has been applied to a clean, oxidation free metal surface, it can then be coated with the primer and topcoat of choice.

This formula is a two part polyvinyl butyral zinc chromate metal pre-treatment that etches itself to metal using an acid diluent as part of its chemistry. This mix was originally formulated as a deck primer for U.S. Navy sea going vessels to help enable them to resist the elements of their extremely harsh saltwater environment. It has also been used for other military vehicles used on land, air and sea, due to its superior adhesion and extensive rust protection qualities.

Zinc is the key ingredient used in the process of galvanizing, which is now a broadly used process named after Luigi Galvani, the man who developed the technique. Zinc is more electrochemically reactive than iron, and prevents rust by oxidizing itself rather than the metal it protects. It is a very effective foundation for all other coatings to be used. Since this product has been developed for the demands of a wide range of military use, including bridges and other equipment, it has had to meet or exceed a number of demanding field test requirements to qualify it.

Due to the acid content, the solution reacts chemically with the metal, using an acid diluent within its chemistry that enables it to attach (etch) itself to the bare metal surface with no voids. It also creates an excellent paintable surface that works well with a wide variety of coatings to be applied over it. It attaches itself rather than coating the surface like a typical primer. Since most primers coat the surface rather than chemically attaching to it, they can often leave tiny voids between the metal and coating that traps oxygen. This condition can lead to the formation of oxidation that will eventually progress, creating rust bubbles underneath the paint surface. A needlessly annoying occurrence that many car owners have experienced. It not only attaches itself chemically to the metal, but is also loaded with zinc. Zinc has long been known to sacrifice itself to oxidation.

Unlike the past, many of today's automobiles are manufactured using galvanized steel panels which enables them to resist rust. Most people who have been around for a while can remember buying a brand new car, and then noticing rust bubbles appearing under the paint within a few short years of its existence.

Many older classic cars such as the MGA and Austin-Healey were manufactured using aluminum exterior panels attached to steel framework to decrease weight. The manufacturers at the time did not realize they were creating an oxidation time bomb. Over a period of time, the two surfaces eventually rubbing together produced an electrochemical reaction that would eventually lead to rust.

This product can be used on bare stainless steel, iron, carbon steel, galvanized steel, galvanized iron, tin, chromium, tin plating, zinc, aluminum, and cadmium. It conforms to Federal Military Specifications MIL-P-15328, SSPC Paint 27 & U.S. Navy Formula 117. Contains no lead pigments. It is for use on clean, oxidation-free, prepared automotive carbon steel and aluminum surfaces.

As with any chemical product, the user must read the Material Safety Data Sheet (MSDS) to educate themselves prior to use.

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Navy 117 Technical Data Sheet (pdf file)

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