High Performance Marine Paints & Coatings For Metal
The Toughest Marine Grade Paints For Metal And Steel – For The Harshest Environments
Are you looking for the best marine grade paint for metal? By using the right high performance coatings to prevent rust and corrosion, you can significantly extend the useful life of your boats, barges, pontoons, transport equipment, boat trailers, I-beams, docks, bulkheads, bridges, waste water clarifiers, or other metal structures in any salt air or salt water marine environment. Our marine paints have some of the highest salt corrosion resistance ratings in the market. (As high as 15,000 hours on the ASTM B117 salt spray test). You can apply our marine coatings directly over rusted metal or steel and they don’t require sandblasting.
When the integrity of the metal has been compromised, our coatings can bond to, and strengthen, rusted metal surfaces, therefore inhibiting corrosion for many years. Our waterproof corrosion coatings can protect metal / steel that will be underwater or exposed to constant high humidity. Whether your project is above or below the waterline, we have your solution!
Marine Painting Projects
Rust Grip®, Moist Metal Grip and Enamo Grip were all used to coat the Blue Chip Chip Casino II (below). In 2006, it was the largest casino boat in the world. As Rust Grip® can be applied over tight surface rust, by eliminating the need to sandblast, over $2 million was saved on the project.
Rust Grip is first applied to encapsulate tight surface rust. It soaks in to the pores of the metal, gasses out trapped oxygen, and creates an air vapor barrier that dries about twice as hard as concrete. Moist Metal Grip, our marine grade corrosion resistant water-repelling epoxy is applied over the Rust Grip to completely water seal the surface. Enamo Grip, our waterproof UV resistant enamel urethane, is applied over Moist Metal Grip as a top coat for a hard durable finish.
This project was completed by January of 2006 and was later inspected in 2019. After more than 13 years in the water, the coatings were still fully intact with no problems. This 3 coating system is an excellent choice for long-term performance on on the exteriors of metal boats, docks, and structures that will be submerged in salt or fresh water.
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Here’s an example of how you can give a new life to an older steel barge. After prep, this barge was painted with Rust Grip®, Moist Metal Grip, and Enamo Grip (3 coat barge paint system).
When painting areas above the waterline like decks, railings, stairs, walls, etc., Rust Grip® is strong enough to be used on its own; no other primers or top coats are required. If a specific color is desired, you can top coat Rust Grip with Enamo Grip.
Our 3-coating system is an excellent choice for any exterior (or interior) metal or concrete that may be fully submerged such as docks, retaining walls, and waste water clarifiers.
ISO 12944-6 C5H Testing Certification:
ISO 12944 is the international benchmark for protecting steel structures with high performance paint. Its C5 (“Very High”) category covers the most aggressive conditions — high-salinity marine and coastal zones, persistent humidity, and repeated wet–dry cycling. The “H” (High Durability) rating certifies an expected service life of 15 to 25 years before first major maintenance when applied over properly prepared steel at the specified dry film thickness. To qualify, the paint or coating system must pass a demanding 1,680-hour cyclic aging test that alternates UV exposure, condensing humidity, neutral salt spray, and low-temperature cycling, using sample panels. The panels are then assessed for blistering, rusting, cracking, and adhesion loss per ISO 4628. For critical marine, coastal, and oil & gas applications—including commercial vessels, offshore platforms, docks, port facilities, storage tanks, coastal bridges, and waterfront infrastructure. An ISO 12944-6 C5H qualified coating system gives engineers, specifiers, and owners documented assurance that their assets will resist aggressive saltwater environments, reduce recoating cycles, and significantly extend asset life.
Which coating systems have passed ISO 12944-6 C5H testing, and at what film thickness?
We offer three independently tested C5H build options at increasing dry film thickness (DFT), so the system can be matched to the severity of exposure:
Rust Grip®* @ 8 mils (200 microns) DFT – single coating system when used above the waterline.
*Rust Grip® (ULVOC) was used for the 8 mil test; it contains VOC exempt solvents that evaporate during curing. Performance of Rust Grip® and Rust Grip® (ULVOC) is identical.
All three options passed the ISO 12944-6 C5H cyclical testing and qualified in compliance with (PDO) Specification SP-1246 as coating system PCS-1A (for Gulf oil and gas production facilities). Higher total DFT delivers greater protection in the most aggressive marine, coastal, industrial zones, and full submersion protection, while the lighter build is suitable for less severe exposures or maintenance applications above the waterline.
What types of structures are ISO 12944-6 C5H systems used to protect?
These systems are commonly specified for:
Offshore oil and gas platforms
Marine terminals, ports, and harbor infrastructure
Docks, jetties, piers, and waterfront structures
Coastal and highway bridges
Storage tanks and process vessels
Ships, barges, and marine vessels
Pilings and submerged marine foundations
Wastewater treatment facilities
Petrochemical and industrial steel infrastructure
Heavy equipment and supporting structures
We’ll Help You Get the Best Results for Your Project. Call Us for a Custom Quote! 917-836-7816
“We have been in the steel barge construction and repair for more than 20 years and normally we sand blast and prep the steel before coating. Some compartments on older barges we can’t blast and prep properly. That’s when we use Rust Grip. We are very pleased with this product.”
Gerald Morrison
President,Morrison Manufacturing Inc., ME
“Warren County PennDOT is very pleased with the performance of Rust Grip with our numerous projects throughout the spring and fall. Not only were we satisfied with the product, but the customer service and price was unbeatable. Looking forward to ordering more Rust Grip next spring!”
Edward Dorunda
Project Manager,Pennsylvania Department of Transportation, PA
Rust Grip® is a great all around marine grade maintenance coating for interiors or exteriors. It can be easily applied with a brush, roller, or sprayer and as a 1-part, 1 coating system, you won’t need any other coatings. This shortens project times and reduces your maintenance costs. You can use Rust Grip® to encapsulate rust or over firmly bonded paint on floors, walls, decks, doors, beams, and more. It’s a highly effective paint for barges and boats used in fresh or salt water. Here’s an example of application on the floor of a metal boat:
Have Questions? Get Expert Recommendations for Your Project.
Longest Lasting Rust Prevention and Corrosion Encapsulating Paint
As a three-coats-in-one system, Rust Grip® acts as a primer, intermediate, and topcoat that strengthens to 6780 psi when fully cured (almost twice as hard as concrete). You can apply it directly over rusted metal, steel surfaces, or firm existing paint, with no white sandblasting required. With a 15,000 hour salt spray test (ASTM B117) rating, Rust Grip® is one of the most effective anti-rust / anti-corrosion paint for barges, boats, and structures. Especially in salt water / salt air marine environments. More…
Superior Corrosion Protection For Wet Or Submerged Metal
When surfaces are too wet to apply Rust Grip®, Moist Metal Grip, our water repelling epoxy, can be applied directly to prevent further surface corrosion. It is ideal for metal exposed to submersion (boat bottom paint), heavy condensation, or where constant water splash is a concern. You can use Moist Metal Grip for metal that will be underwater, buried, or below grade. It is also resistant to chemicals and solvents. More…
Strong Durable Waterproof And UV Resistant Top Coat
A high performance, fully waterproof two-part marine grade polyurethane enamel coating that is an excellent choice for a variety of applications. You can use it on boats, railings, stairwells, pipes, walls, or submerged structures. Enamo Grip is self leveling and can be tinted to any exact color specification or finish. Our Enamo Grip SAS formulation provides a slick surface to resist barnacles and algae from attaching on to boat hulls. More…
Thermal Heat Reflective Coating That Blocks More Than 95% Of Solar Heat
Our solar heat reflective ceramic coating can be used for a wide range of applications. The ceramics in Super Therm block infrared, UV, and visible light from heating a surface and keeping it cool while in direct overhead sun. More…
Marine Paint FAQ
1. How should rusted barges, boats, marine vessels, and structures be prepared before coating?
Preparation is important: Remove moderate and loose rust, loose paint, grease, grime, etc. so that at a minimum, surfaces are brought to a combination of tight surface rust, firmly bonded paint, and some bare metal. You can use machine tools such as grinders with wire cup brushes or 40 grit flap discs (SSPC-SP 3). Power wash/clean to remove residues, dirt, etc.
As Rust Grip is designed to encapsulate tight surface rust, flash rust, and firmly bonded existing paint, white sandblasting (SSPC-SP5) is not required.
For heavier, deeply pitted rust, scale, and pack rust, a commercial level blast (SSPC-SP 6) or Commercial Grade Power Tool Cleaning (SSPC-SP 15) may be specified.
Removing salts by power washing with a salt remover (like Chlor-rid) is critical for coating performance. Power washing alone will not remove all salts.
Allow surfaces to thoroughly dry. Do not power wash and apply coatings on the same day.
2. What is the advantage of encapsulation coatings in marine maintenance?
Encapsulation coatings allow corrosion and existing coatings to be stabilized rather than fully removed. This reduces:
Surface preparation requirements
White abrasive blasting cost and downtime
Waste containment and disposal from blasting operations
Operational disruption during maintenance
This approach is commonly used in marine rehabilitation and steel asset life extension programs.
3. What coating system is recommended for fully submerged or splash-zone marine steel?
For submerged, hull, or splash-zone applications, a layered system is typically used:
Rust Grip® – corrosion encapsulation and primary barrier layer
Moist Metal Grip® – water-repelling epoxy for wet or submerged exposure
Enamo Grip® – UV-stable topcoat for above-waterline weathering protection
An additional advantage to using a system like this is that each coating can be a different color and thin spots during the application can be easily seen. This will help ensure an even, more consistent application at the correct thickness for maximum protection.
This system is designed for aggressive marine immersion environments requiring long-term corrosion resistance.
4. What is the best coating system for rusted metal structures above the waterline?
For decks, railings, bulkheads, and above-waterline steel, Rust Grip® can be used as a stand-alone encapsulation coating over properly prepared tight surface rust rust. Rust Grip® is fully UV stable and as it contains aluminum pigment for strength, it is light grey with a matte finish.
If a specific color with high UV stability is desired, Enamo Grip® can be applied as a topcoat. Non-slip aggregates may be added for walking surfaces or high-traffic areas where safety performance is required.
5. What coatings work best for bridges, docks, marinas, and structural steel near saltwater?
For bridges, marinas, docks, retaining walls, cranes, heavy equipment, and structural steel, Rust Grip® is an excellent choice for pure corrosion protection. It has one of the highest salt-resistance ratings of any marine paint (15,000 hours on ASTM B117). Above the waterline, it works as a stand-alone single-coat system. For steel that will be buried, sits below the waterline, or requires a specific color, add a water-repelling epoxy (Moist Metal Grip) and/or a waterproof, UV-resistant topcoat (Enamo Grip) depending on the application.
6. What is ISO 12944-6 C5H certification and what does it mean for specifiers?
ISO 12944-6 C5H certification verifies that a complete coating system has passed accelerated laboratory testing for use in very high corrosivity environments, including marine, coastal, offshore, and heavy industrial exposure.
The test evaluates coating performance under cyclic conditions that simulate real-world corrosion mechanisms, including salt exposure, humidity cycling, condensation, UV exposure, and temperature variation. Systems are assessed for corrosion resistance, adhesion, blistering, cracking, flaking, and corrosion creep in accordance with ISO 4628 standards.
What does C5H mean in practical engineering terms?
C5H represents:
C5 (Very High Corrosivity): marine, coastal, offshore, and industrial salt environments
H (High Durability): long-term service life of approximately 15–25 years before first major maintenance
It is used for steel structures exposed to continuous or frequent chloride exposure, high humidity, and aggressive atmospheric corrosion where extended maintenance intervals are required.
How is ISO 12944-6 C5H testing performed?
Testing is conducted on complete coating systems applied to steel panels and exposed to accelerated cyclic corrosion conditions, including:
Neutral salt spray exposure
Condensing humidity cycles
Wet/dry cycling
UV exposure
Low-temperature cycling
After exposure, panels are evaluated for corrosion performance, including rusting, blistering, cracking, adhesion loss, and corrosion creep at the scribe line using ISO 4628 rating criteria.
What determines the durability of a C5H coating system?
*Rust Grip® (ULVOC) was used for the 8 mil test; it contains VOC exempt solvents that evaporate during curing. Performance of Rust Grip® and Rust Grip® (ULVOC) is identical.
Each system provides increasing levels of barrier protection based on total film build and environmental severity.
How do engineers select the correct C5H coating system?
System selection is based on exposure severity, access conditions, and lifecycle requirements:
Lower-build systems are typically used for atmospheric exposure and maintenance applications above the waterline
Mid-build systems are used for general marine and coastal steel exposure
High-build systems are specified for offshore, splash zone, full submersion/continuously wet, or high-chloride environments requiring maximum barrier protection
Note: Coating systems formerly classified under ISO 12944 C5-M (marine) are now designated C5 or CX under the 2018 revision.
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