Frequently Asked Questions

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The fact is, a new vehicle is subjected to thousands of spot welds and numerous bends and folds during production. This process damages the pre-coated metal, allowing exposure to the corrosion process. Besides cosmetic damage, corrosion also weakens a vehicle’s structural integrity and can affect steering and suspension components. This product is designed to create a barrier that can’t be broken, chipped, or cracked. By staying fluid, our petroleum-based rust protection heals back over after any abrasions providing lasting protection, even in extreme conditions.


Unlike paint or conventional undercoating, which covers and encapsulates rust, our oil penetrates through rust to the base metal. Our oil is self-healing, designed to displace moisture and remove oxygen. Take either out of the equation, and oxidation cannot occur. Our corrosion inhibitors will then fight rust on a chemical level. Our oil is formulated to penetrate deep into seams, body cavities, and spot welds, creating a barrier against the elements in an environment prone to hold moisture and conducive to corrosion.


With the introduction to road brine (liquefied salt), this extremely corrosive solution is now able to penetrate deep into your vehicle’s body cavities where rock salt could not. Many of these road brine solutions contain magnesium chloride, calcium chloride, and additives to help them stick to surfaces.


The problem is, they don’t discriminate. For most people, a car wash is their maintenance program. Unfortunately, this can prove detrimental to combating corrosion. Many car washes recycle water, likely not eliminating all of the corrosive solutions. Combine that with the fact that it’s pushing with high-pressure water into your vehicle’s undercarriage where it was never intended to be, which can be very counterproductive.

NH Oil Undercoating Will provide you superior protection. It remains soft. It compensates for heat and will not dry or crack like traditional hard-coatings and substantially reduce the corrosive effects your vehicle is subject to during winter conditions. In our opinion, Oil-based rustproofing is the most forgiving way to treat corrosion.


Here is how it works!

How Oil-Based Rustproofing works
What is the difference between NH Clear & Back-N-Black Oil
Exact same product other than a carbon graphite biodegradable black tint to improve the surface appearance.
What is NH Oil Undercoating® made from?

NH Oil Undercoating® is a highly refined food-grade mineral oil product. Formulated with the environment in mind, NH Oil Undercoating is a nonhazardous unregulated product. It causes no health or flammability hazards.

The technical term is resolute oil, otherwise known as mineral oil. It is a food-safe grade oil, which means you can consume it in small quantities. Of course I’m not encouraging you to try. However, we had a customer call last year whose pet dog did just that. The only adverse reaction was loose stool! No solvents and no detergents. Corrosion inhibitors are all green and environmentally friendly.

Our oil has natural corrosion inhibitors otherwise known as “green inhibitors”, derived from plants and animal fats. Contains no solvents or detergents. It is an environmentally friendly product considering it does not drip. (Minimal dripping may occur). Our NH Back-N-Black has a biodegradable tint, otherwise the same as the clear product.

In our opinion, Oil-based rustproofing is the most forgiving way to treat corrosion.

Our oil is formulated to displace moisture, the presence of oil will deprive the surface of oxygen. When you take either out of the equation, oxidation cannot occur, so as long as the product is present rust is held at bay. NH Oil will simultaneously fight corrosion on a chemical level as well. The presence of the oil will form a barrier to protect the surface. NHOU Is formulated to migrate and creep. This is especially important to the weak areas of a vehicle, rocker panels, door panels, etc. areas that are by design prone to rust. The surfaces are generally unprotected with a finish (paint), prone to hold moisture and are very thin. Over the course of a warm month, it is not uncommon for our oil to move as much as several inches. In a cross member of a pickup truck bed, that would encapsulate the entire inside surface area. Having some surface rust can actually be a plus. Much like using an abrasive to scuff a surface prior to applying a finish, the rust will give the product something to hang on to.

Will it void my warranty?
Absolutely not! Because NH Oil Undercoating® is an entirely different approach, it eliminates annoying electrical malfunctions and makes the vehicle work better and last longer. While the manufacturers probably won’t admit it, they just have to love NH Oil Undercoating® because it will reduce the number of corrosion related warranty claims they are obligated to pay. It also saves customers the time and aggravation associated with claims against warranties. NH Oil Undercoating is used and sold by most major manufacturers dealerships.
Will it drip
NH Oil Undercoating is formulated not to drip. However, minimal dripping may occur if the product is applied heavily. In most cases clean up is simple, Dawn dish soap or Simple Green usually does the trick.
Do you clean the vehicle first
Check with your dealer, each shop is independently owned and operated. In most cases, if your vehicle arrives with a heavy residue of mud, flaky rust it would be necessary to wash/remove before treatment. We recommend that any heavy accumulation of mud and dirt be pressure washed from the frame and wheel wells a day prior to the application.

Note, arrangements may be necessary to allow adequate time for preparation and additional costs may occur.

Can it be done if the car is wet?
Of course it can. Because OIL chases water, it can be applied on rainy days. Water actually accelerates the creeping abilities because it moves quickly on wet surfaces to attack and displace moisture in tight seams and hard to reach crevices. Some competitor’s products are designed to mix with water with the idea that when the product drips off, the water goes with it. Not so with our products. We make sure that our chemical chases only the water from the metal. This is another reason why our products give longer lasting protection to your vehicle.
How soon can I wash my car?

You can wash your vehicle immediately after the treatment. (avoid high-pressure undercarriage washing) Unlike other preventing methods, it will not trap moisture. It literally pushes it away, leaving behind a corrosion-fighting lubricating film.

How is it applied?

NHOU is atomized under high pressure which pushes the product deep into the seams, cracks and crevices where corrosion starts. Once applied, the product removes the moisture in these areas and provides a strong adherence to these surfaces, remaining active with excellent “creeping” and self-healing abilities.

You may notice smoke and odor from the underside of the vehicle the first time the vehicle is driven. This is due to a small amount of overspray vaporizing on the exhaust system. It is harmless and should cease quickly.
You may notice a grinding noise when braking. This is due to a small amount of over-spray collecting on the brake lining. This is not a safety hazard and should cease after a few stops. Paint: NHOU’s products cannot stop scratches, peeling of paint or stone chips. Damage to exterior paint should be repaired promptly otherwise surface corrosion can occur.
About us
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How often should NH Oil Undercoating be applied
While driving habits may vary, we recommend an annual application in order to maintain adequate protection.
What is the bulk flash point of NH Oil Undercoating® NAS?
The bulk flash point of NH Oil Undercoating® NAS is 425 F.
Will NH Oil Undercoating® harm electrical connections ?
No. NHOU is non-conductive and will not harm electrical connections. Make sure that all connections are made before applying NHOU.