NHOU® Marine Corrosion Guard Aerosol
Clear Rust Inhibitor for Outdrives, Lower Units & Marine Electrical
Price range: $34.78 through $166.92
A rust-inhibiting oil in an aerosol that forms a clear, water-displacing, non-conductive barrier on painted and non-painted metal. Use it on outdrives, lower units, power trim motors, electrical components and engines in storage.
- Clear, doesn’t peel
- 2-pack or case of 12
Not available to California residents.
Keep Saltwater Off Your Boat’s Metal
Outdrives, lower units, trim motors and wiring live in the harshest environment there is. Saltwater and airborne chemicals go to work on bare and painted metal every time you launch.
NHOU® Marine Corrosion Guard is a rust-inhibiting oil in an aerosol. It displaces moisture and forms a clear, non-conductive, water-resistant barrier that doesn’t peel.
What It Does
- Displaces moisture and blocks airborne chemicals that cause rust and corrosion
- Clear, non-conductive, water-resistant barrier that doesn’t peel
- Use on painted and non-painted metal
- Protects inboard and outboard engines during long-term storage
- Operating range: −10°F to 200°F
Where to Use It
Don’t spray on
- Surfaces coated with anti-fouling or biocide paint
- Drive belts or soft natural rubber
How to Apply
Check conditions
Air and can between 50°F and 80°F, humidity 60% or less. Avoid wind and dust, and cover the surrounding area.
Clean
Remove dirt, wax, grease and saltwater deposits with a high-quality cleaner. Rinse and let dry.
Shake
Shake vigorously for one minute after the mixing ball begins to rattle.
Spray
Hold upright 6–10″ away. Apply thin, even coats with a steady back-and-forth motion, releasing after each stroke.
Clear the valve
Turn the can upside down and spray until clear gas comes out.
How often: reapply before storing your boat, and every week if you boat in saltwater. Clean up overspray with Simple Green® or dish soap. Dispose of empty cans per local, state and federal regulations.
Protect the Trailer, Too
NHOU® Salt-Brine Eliminator
Removes salt from trailers and mechanical parts exposed to saltwater.
Shop Salt-Brine EliminatorNHOU® Oil Undercoating
Creeping oil protection for trailer frames and hardware.
Shop Oil UndercoatingNot available to California residents. Learn more about Marine Corrosion Guard →
| Weight | N/A |
|---|---|
| Dimensions | N/A |
| Pack | 2-Pack, Case of 12 |
| Brand | NHOU |
| Size | 12 oz Aerosol |
Using it
What is NHOU Oil Undercoating for?
It protects your vehicle’s underbody from rust caused by road salt, liquid de-icers and winter driving. It penetrates seams, spot welds and cavities, displaces moisture and blocks oxygen, then stays active to keep moisture away from bare metal.
It works at every stage: new vehicles, light rust and heavy rust (use Rustoration® first).
How much do I need?
It depends on the size of your vehicle and its condition. Contact us and we’ll recommend the right size for your vehicle.
What prep and equipment do I need?
- Clean first: if the vehicle has heavy mud or flaky rust, pressure wash it, especially around the frame and wheel wells, ideally a day before application.
- Wet is OK: the oil chases water, so damp conditions are fine. Dry is ideal; don’t apply in heavy rain.
- Electrical: make sure all connections are made before applying.
- Heavy rust: convert it with NHOU® Rustoration® first.
- Equipment: applicators use high-pressure equipment that atomizes the oil. Doing it yourself? Start with the DIY Kit.
How do I apply it?
NHOU® is atomized under high pressure, pushing it deep into the seams, cracks and crevices where corrosion starts. Cover the frame, wheel wells and hard-to-reach areas like rocker panels and door cavities. Once applied, it removes moisture, adheres to the surface and keeps creeping to self-heal.
Watch installation videos, or find an applicator to have it done for you.
What should I avoid?
- Keep it off brakes, exhaust systems and soft rubber molding.
- Don’t apply during heavy rain.
- Avoid undercarriage car washes between treatments. Most recycle salty water, and high-pressure jets can force salt back into body cavities.
- Don’t count on it for paint. It doesn’t prevent scratches, peeling paint or stone chips.
You may notice some smoke and odor the first time you drive. That’s a little overspray on the exhaust burning off; it’s harmless and stops quickly.
How do I maintain the protection?
- Reapply once a year for consistent protection.
- Clean the undercarriage before your next application.
- Keep high-wear spots topped up with Touch-Up Cans.
- Repair paint chips promptly to prevent surface rust.
About the product
Clear or Black: which should I choose?
Both give the same trusted protection. Black adds a biodegradable tint for a clean, black underbody finish. Clear leaves surfaces looking natural. Both come in 1, 5 and 55 gallon sizes.
Does the peppermint change how it works?
No. It’s the same proven oil-based formula. The only change is a fresh peppermint scent.
Will it drip?
It’s formulated to be low-drip. After heavy application, minimal dripping may occur, and it cleans up easily with Dawn® dish soap or Simple Green®. Want drip-free? Try NHOU® V3.
Will it harm electrical connections?
No. NHOU® is non-conductive and will not harm electrical connections.
Will undercoating void my vehicle warranty?
No. Under the federal Magnuson-Moss Warranty Act, a manufacturer can’t void your warranty just because you used an aftermarket product, unless they can prove that product caused the problem.
Where is the Safety Data Sheet?
Open the SDS Info tab on this page. Need help? Contact us.
