5 Things you should know before you decide which is the best Oil to use for Undercutting


In short, not all undercoatings are created equal.

There are many, many brands and varieties of undercoating: NH Oil Undercoating ® Rustoleum, 3M, Eastwood, Bar and Chain Oil, Used Motor oil, etc. etc. finding a product that engineered the correct application will play a role on whether it actually works??

The problem is, depending upon the circumstance and the degree to which rust is present on a vehicle’s underbody, the results greatly vary, especially after months and months of unpredictable weather.

Most of these brands (Rustoleum, 3M, Eastwood POR-15) produce rubberized versions of undercoating in a can. These types of coatings have a dried film that is often quite hard, arid, and brittle.

They were not engineered to displace moisture. As a result, you need to apply only to a clean, rust-free surface. Encapsulating rust will not slow it down. In fact, sometimes, the trapped air and moisture may even contribute to rust formation and accelerating. Slightly disguises the problem at best.


Do you have pre-existing rust?


If so, then you should avoid wax, paint, and rubberized products. These products only trap moisture below the surface, allowing oxidation to continue. Oil-based rustproofing will penetrate through the rust down to the good metal, displace moisture while removing oxygen, and has long been a home remedy for rust formation. Take either moisture or oxygen out of the equation, and oxidation cannot occur. Use a petroleum-based product with rust inhibitors containing no solvents. In fact, the NH Oil Undercoating product is environmentally safe, contains no toxins, is non-flammable. Won’t swell the rubber pushing seals or gaskets found on your vehicle’s undercarriage. Will creep and migrate into the spot welds seams and folds of the body cavities.


Thinking about coating your vehicle with used motor oil? Consider this….

Used motor oil contains numerous toxic substances, including polycyclic aromatic hydrocarbons, which are known to cause cancer. In addition, tiny pieces of metal from engine wear and tear, such as lead, zinc, and arsenic, make their way into lubricants, further contributing to the polluting potential of used motor oil. Motor oil is exposed to heat and oxygen during engine combustion, which changes its chemical makeup. Detergents and solvents are detrimental to the rubber bushings, gaskets, and seals on your vehicle’s undercarriage. Because spent motor oil is heavy and sticky, and contains an extensive concentrated cocktail of toxic compounds, it can build up and persist in the environment for years. Not to mention the drip, drip, drip….