MARINE COATINGS

Strictly speaking, no, marine coatings aren’t necessary. However, for many private, commercial, and industrial applications, marine coatings may be all but required. They’re used to protect marine structures like ships or docks from the harsh conditions of seas, oceans, and other saltwater and freshwater environments. Without them, marine structures are more susceptible to corrosion, fouling, and other common stressors.

Marine coatings have become nearly ubiquitous, and for good reason. Marine coatings can help greatly extend the lifetime and performance of ships, docks, buoys, propellers, offshore structures and more. They protect against corrosion, fouling, forceful impacts, harsh abrasion, and many other risk factors, making them well worth the investment for almost any marine infrastructure.

One of the biggest disadvantages to marine coatings is that no matter the type or quality of protective coatings, marine conditions are aggressive enough to wear even the newest and most advanced materials technology. They should be professionally applied and carefully maintained, and it’s critical to choose the right marine coatings for each unique application.

No — and this is an important distinction. Polyurea is a barrier coating. It is engineered to stop corrosion, abrasion, impact and water intrusion, but it does not contain the biocides that antifouling paints use to prevent barnacles, algae and other marine growth from attaching to a hull.

For most of what floats and everything that does not — decks, docks, pilings, bulkheads, ballast and potable water tanks, buoys, splash-zone steel, hatches and workboat interiors — polyurea is the stronger long-term answer. For a hull that sits below the waterline and needs fouling control, polyurea is used as the protective barrier and an antifouling topcoat is applied over it. Any contractor who tells you one product does both jobs is overselling.

Marine epoxies are hard, rigid and chemically resistant, but that rigidity is also their weakness: they are relatively brittle, they crack when a substrate flexes or takes an impact, and once the film is breached corrosion spreads underneath it.

Polyurea is an elastomer. ArmorThane ArmorShield cures to roughly 400% ± 50% elongation at 50 Shore D hardness — it stretches and rebounds with the structure instead of fracturing. It is seamless, with no laps or joints for water to track behind, and far less sensitive to moisture and temperature during application. Epoxy typically needs hours to days between coats; ArmorShield is tack-free in under 60 seconds.

Very fast. ArmorShield reaches a tack-free state in less than 60 seconds and can be applied in single or multiple passes without appreciable sagging. In practice most marine projects can be sprayed and returned to service the same day, rather than losing a vessel or a dock to a week of cure time.

Fast set also makes the material relatively insensitive to moisture and ambient temperature during application — ArmorShield can be applied in conditions down to -20°F (-28.9°C), which matters for northern yards and winter maintenance windows.

ArmorThane marine systems bond to a wide range of substrates. ArmorFlex UV forms a continuous, seamless membrane on concrete, metal, fibreglass, wood and geotextile fabrics. ArmorShield is formulated for suitably prepared concrete and metal. AquaShield coats carbon and mild steel without a primer.

Substrate condition matters more than substrate type. Every surface must be clean, dry, structurally sound and correctly profiled before spraying.

Surface preparation is the single largest predictor of how long a marine coating lasts. Steel is typically abrasive-blasted to a specified cleanliness and anchor profile so the polyurea has mechanical tooth to grip. Concrete is usually blasted or ground to remove laitance and open the pore structure. Fibreglass and gelcoat are abraded to break the gloss.

Contamination is the enemy: chlorides, oil, grease and residual moisture will undermine adhesion no matter how good the coating is. On marine work, salt-contaminated steel should be washed and tested for soluble salts before blasting.

It depends on the chemistry, and being straight about this matters. Aromatic polyureas such as ArmorShield and AquaShield are extremely durable, but like all aromatic systems they will shift colour and chalk at the surface under prolonged UV exposure. This is cosmetic — the physical protection underneath is unaffected.

Where appearance matters — topsides, visible decks, branded surfaces, architectural marine work — ArmorFlex UV is the answer. It is an aliphatic polyurea formulated specifically to be colour-stable in sunlight.

Yes, and it is one of the most common marine requests we see. Because polyurea is spray-applied, texture is built into the system: aggregate is broadcast into the wet film and locked in, producing a slip-resistant surface that can be tuned from lightly textured to heavily aggressive.

The same approach works on boat decks, swim platforms, dock surfaces, ramps, pool decks, walkways and marina gangways — anywhere a wet surface becomes a fall hazard.

Yes. AquaShield is ANSI/NSF 61 approved for direct contact with potable water and meets USDA criteria. It is a fast-setting, 100% solids, flexible aromatic spray polyurea that can be applied to prepared concrete and metal, coats carbon and mild steel without primer, and is odourless with no toxic vapours.

That makes it suitable for potable water tanks afloat and shoreside, for tanks from 5 gallons upward, and for pipe 9″ in diameter or greater.

ArmorShield is a zero-VOC, 100% solids system — there is no solvent carrier, so there is effectively nothing to evaporate. It is also odourless, which is a genuine practical advantage when spraying inside a hull, tank, bilge or any other confined marine space where solvent-borne paints create ventilation and safety problems.

Rather than quote a misleading per-square-foot figure, it is more useful to know what actually moves the number: total area; the condition of the existing substrate; how much preparation and abrasive blasting is required; whether old coating must be removed; specified film thickness; which product the environment calls for (aromatic vs. aliphatic); access and containment; and whether the work happens in a yard or on site.

A sound dock deck and a corroded splash-zone piling are very different jobs. The fastest route to a real number is a scope-specific quote.

Service life is a function of three things: how well the surface was prepared, how much film thickness was applied, and how aggressive the exposure zone is. A properly prepared, correctly specified polyurea system in atmospheric marine exposure will substantially outlast conventional paint. The same product sprayed thin over poorly prepared steel in the splash zone will not.

This is why ArmorThane sells through trained, certified applicators rather than over the counter. ArmorThane has been formulating and supporting protective coatings for over 30 years, and correct specification is part of the product.