ALKA-9939 

Splash & Tidal Zone Protective Coating System

Heavy-duty high-build marine barrier system designed for steel structures exposed to severe splash, tidal, intermittent immersion and repeated wet/dry seawater cycling.

PROTECTION STRATEGY

ALKA-9939 uses a:

Prepared Marine Steel → Substrate-Specific Primer → Glass-Flake / Ultra-High-Build Epoxy Barrier

strategy.

The primer is selected to provide the correct interface between the prepared steel and the severe-duty marine barrier layer.

The main protective layer is then provided by either:

ALKA-414 Glass Flake Epoxy

or

Approved ALKA Ultra-High-Build Epoxy System

depending on the required total film build, geometry, exposure severity and project specification.

The system is designed to create a thick, continuous and highly protective barrier against:

• Direct seawater contact
• Chloride penetration
• Repeated wet/dry cycling
• Splash exposure
• Tidal immersion
• Persistent moisture
• Marine atmospheric contamination

KEY PERFORMANCE BENEFITS

• Designed specifically for marine splash and tidal zones
• Suitable for repeated direct seawater exposure
• Heavy-duty high-build barrier construction
• Glass-flake reinforced epoxy option
• Ultra-high-build epoxy option
• Suitable for intermittent immersion
• Suitable for severe wet/dry cycling
• Designed for high chloride exposure
• Suitable for critical marine infrastructure
• High protective film thickness
• Suitable for difficult-access marine assets
• Robust barrier against moisture and seawater penetration
• Project-specific primer selection
• Project-specific DFT selection
• Suitable for new construction and major marine refurbishment
• Suitable for wharves, jetties and piling structures
• Strong option where atmospheric marine coatings are insufficient
• Functional severe-service system where protection takes priority over appearance

PRIMER — SUBSTRATE-SPECIFIC ALKA PRIMER

Function: Adhesion and Initial Corrosion Protection

The primer is selected according to:

• Steel condition
• Surface preparation
• Exposure zone
• Selected ALKA barrier system
• Required compatibility
• Project specification

The primer establishes adhesion and provides the foundation for the high-build marine barrier.

Product: Project-approved ALKA primer
Position: Directly over prepared marine steel
Primary Function: Adhesion and initial corrosion protection
Nominal DFT: Project-specific / current ALKA TDS

BARRIER OPTION 1 — ALKA-414 Glass Flake Epoxy

Function: Heavy-Duty Reinforced Marine Barrier

ALKA-414 forms a high-build, glass-flake reinforced epoxy barrier designed for severe wet-service conditions.

The glass-flake reinforcement increases the tortuous path through the coating film and supports improved barrier performance against direct marine exposure.

Product: ALKA-414 Glass Flake Epoxy
Position: Main marine barrier coat
Primary Function: High-build reinforced seawater barrier
Nominal DFT: To project specification and current ALKA TDS

BARRIER OPTION 2 — Approved ALKA Ultra-High-Build Epoxy System

Function: Ultra-High-Build Severe Marine Protection

Where the project requires greater total film build or a more substantial barrier than the standard glass-flake configuration, an approved ALKA ultra-high-build epoxy system may be specified.

This option is particularly relevant where:

• Exposure severity is extreme
• Steel geometry is complex
• Greater total barrier thickness is required
• The structure is difficult to access for future maintenance
• The project design life justifies a heavier build

Product: Approved ALKA Ultra-High-Build Epoxy
Position: Main severe-duty marine barrier
Primary Function: Very high-build seawater and chloride barrier
Nominal DFT: Project-specific

OPTIONAL ADDITIONAL BARRIER COATS

Additional ALKA-414 or approved barrier coats may be incorporated where required to achieve:

• Target total DFT
• Better continuity
• Increased barrier thickness
• Improved coverage over complex steel
• Project-specific performance requirements

Nominal Total System DFT: Project-Specific

ALKA-9939 does not have one universal total DFT.

The correct film build should be selected according to:

• Splash or tidal exposure
• Intermittent immersion
• Steel condition
• Design life
• Maintenance access
• Number of barrier coats
• Service severity
• Applicable marine specification
• Inspection requirements

Final individual coat and total system DFT must be confirmed against the relevant ALKA technical data and project requirements.

SUITABLE SUBSTRATES

ALKA-9939 is primarily intended for:

Prepared Carbon Steel

Typical assets include:

• Jetty piles
• Wharf piles
• Marine structural columns
• Tidal-zone steel
• Splash-zone steel
• Berthing structures
• Dolphins
• Fender-support structures
• Marine brackets
• Wharf substructures
• Offshore support steel
• Coastal structural steel directly exposed to seawater

Other substrates require project-specific assessment.

SERVICE & EXPOSURE ENVIRONMENT

ALKA-9939 is specifically designed for severe marine wet exposure.

Typical exposure includes:

• Splash zone
• Tidal zone
• Intermittent immersion
• Frequent wave action
• Direct seawater spray
• Repeated wet/dry cycling
• Chloride-rich conditions
• High humidity
• Marine condensation
• Severe coastal wetting

The system should not be confused with atmospheric-only marine systems.

UNDERSTANDING THE EXPOSURE ZONE

Marine structures often contain several different exposure zones.

Atmospheric Zone

Steel exposed mainly to salt-laden air and weather.

Typically better suited to ALKA-9938.

Splash Zone

Steel repeatedly wetted by waves and spray.

A core ALKA-9939 application.

Tidal Zone

Steel alternately submerged and exposed as tides move.

A core ALKA-9939 application.

Immersion Zone

Steel remaining predominantly submerged.

This may require a specifically approved immersion system and should be reviewed independently.

TYPICAL APPLICATIONS

Jetty Piles

Steel piles exposed to regular wave splash, tidal wetting and seawater cycling.

These are one of the clearest applications for ALKA-9939 because the coating must tolerate repeated chloride loading and wet/dry exposure.

Wharf Piles

Marine piling supporting wharf structures where sections of the steel move between atmospheric, splash, tidal and submerged exposure.

The ALKA-9939 system should be applied specifically to the relevant severe exposure zone.

Marine Dolphins

Steel berthing or mooring dolphins exposed to direct seawater, waves and tidal action.

These structures are difficult to maintain and therefore benefit from a heavy-duty high-build barrier system.

Fender Support Structures

Steel frames, brackets and supports associated with marine fender systems.

These components may experience intense seawater spray and repeated wetting during vessel operations.

Wharf Substructures

Steel beams, brackets and support members situated beneath wharf decks where seawater splash and persistent moisture are present.

Jetty Substructures

Structural steel beneath jetty decks, particularly sections exposed to direct spray and tidal moisture.

Splash-Zone Pipe Supports

Marine pipe supports and structural frames exposed to repeated seawater splash.

The process pipe coating itself must be selected separately according to operating conditions.

Tidal Structural Steel

Columns, braces and structural elements that are alternately submerged and exposed as water levels change.

Offshore & Nearshore Structures

Selected support steel and structural components exposed to severe marine wet-service conditions.

Marine Terminal Substructures

Steel components located beneath loading terminals and similar facilities where splash and tidal exposure are present.

Sea Walls & Coastal Steel Structures

Project-approved steel components incorporated into coastal structures and repeatedly exposed to direct seawater wetting.

SURFACE PREPARATION

Surface preparation is one of the most critical factors in severe marine coating performance.

Steel should be prepared to the standard required by the selected ALKA barrier system and project specification.

The process should address:

• Heavy rust
• Scale
• Marine growth
• Chlorides
• Soluble salts
• Oil
• Grease
• Existing coating
• Pitting
• Weld spatter
• Sharp edges
• Fabrication defects
• Moisture
• Condensation

SOLUBLE SALT CONTROL

Marine steel frequently carries soluble chloride contamination.

These salts can remain after visible corrosion has been removed.

If left under the new coating, they can contribute to:

• Osmotic blistering
• Under-film corrosion
• Loss of adhesion
• Premature coating breakdown

Where specified, soluble-salt testing should therefore be carried out after preparation.

If salt contamination exceeds project limits, additional cleaning should be undertaken before coating.

PITTED STEEL

Existing marine steel often contains deep corrosion pits.

These require careful preparation because pits can retain:

• Chlorides
• Moisture
• Rust
• Marine contamination

Pits also create coating-thickness challenges.

They should be thoroughly prepared and coated to achieve continuous film coverage.

Where corrosion has caused significant loss of section, structural repair or engineering assessment is required before coating.

EDGE, WELD & CONNECTION DETAILING

Marine barrier systems require careful treatment of:

• Welds
• Edges
• Bolts
• Nuts
• Brackets
• Corners
• Crevices
• Pile connections
• Complex structural details

Sharp edges should be appropriately treated and weld profiles made suitable for continuous coating application.

STRIPE COATING

Stripe coating should be specified where appropriate around:

• Welds
• Edges
• Bolted connections
• Corners
• Brackets
• Crevices
• Complex fabricated details

This helps achieve sufficient local DFT before full-coat application.

APPLICATION CONSIDERATIONS

Application in splash and tidal environments requires careful planning.

The coating area may need to be isolated from:

• Incoming tide
• Wave splash
• Rain
• Condensation
• Salt contamination

Important application controls include:

• Ambient temperature
• Steel temperature
• Relative humidity
• Dew point
• Surface dryness
• Surface cleanliness
• Mixing ratio
• Mechanical mixing
• Pot life
• Wet-film thickness
• Dry-film thickness
• Recoat interval
• Cure time
• Ventilation
• Protection from seawater before cure

TIDAL WORK WINDOWS

Where coating is applied near active tidal levels, the work sequence must provide sufficient time for:

• Surface preparation
• Cleaning
• Coating application
• Initial cure

before the coated surface is exposed again to seawater.

The required cure period must follow the applicable ALKA technical data.

Coating that is exposed to seawater too early may suffer serious loss of performance.

FILM CONTINUITY

Continuity is critical in ALKA-9939.

A high average DFT is not enough if the coating contains:

• Pinholes
• Holidays
• Missed areas
• Thin spots
• Voids
• Craters
• Poor weld coverage
• Incomplete edge protection

Any discontinuity can allow concentrated seawater contact with the steel substrate.

HOLIDAY TESTING

For critical marine barrier systems, holiday testing may be specified after cure.

This is particularly valuable where the system is used as a continuous lining-type barrier.

Holiday testing should be performed using a method suitable for:

• Coating type
• Total DFT
• Steel substrate
• Project standard

Defects should be repaired and retested before service.

INSPECTION & QUALITY CONTROL

A severe marine protective system requires rigorous quality control.

Depending on the project, inspection may include:

• Steel condition assessment
• Surface-preparation verification
• Blast-profile measurement
• Soluble-salt testing
• Environmental-condition monitoring
• Steel-temperature measurement
• Dew-point monitoring
• Stripe-coat inspection
• Primer DFT measurement
• Barrier-coat DFT measurement
• Recoat-window verification
• Cure verification
• Visual continuity inspection
• Holiday testing
• Final total DFT measurement
• Inspection of welds and edges
• Batch-number recording
• Application-condition records
• Final acceptance inspection

WHY SPECIFY ALKA-9939?

ALKA-9939 should be selected when a marine structure is exposed to direct seawater splash and tidal cycling, conditions for which normal atmospheric marine systems are not designed.

Its protection logic is:

Prepared Marine Steel → Appropriate Primer → ALKA-414 Glass Flake or Ultra-High-Build Epoxy Barrier → Required Total DFT → Continuity Verification

The system focuses on:

High Film Build + Reinforced Barrier + Chloride Resistance + Wet/Dry Cycling Protection

rather than decorative appearance.

WHEN TO CHOOSE ALKA-9939

ALKA-9939 is particularly appropriate when:

• Steel is exposed to direct seawater splash
• Tidal cycling occurs
• Repeated wet/dry exposure is expected
• Chloride loading is severe
• A high-build barrier is required
• Atmospheric marine coatings are insufficient
• Future maintenance access is difficult
• Jetty or wharf piles require protection
• Marine substructures require a dedicated severe-service system
• Glass-flake or ultra-high-build epoxy protection is appropriate

ALKA-9939 VS ALKA-9938

This distinction is critical.

ALKA-9938 — Marine Atmospheric System

For:

• Salt-laden air
• Humidity
• UV
• Rain
• Above-water steel

ALKA-9939 — Splash & Tidal System

For:

• Direct seawater splash
• Wave exposure
• Tidal cycling
• Repeated seawater wetting

In simple terms:

Above-water marine atmosphere → ALKA-9938

Direct seawater splash/tidal exposure → ALKA-9939

ALKA-9939 VS ALKA-9935

ALKA-9935 is a broader glass-flake industrial barrier lining system.

ALKA-9939 uses similar high-barrier concepts but is specifically selected and detailed for marine splash and tidal service.

Therefore:

General severe industrial barrier service → ALKA-9935

Severe marine splash/tidal service → ALKA-9939

ALKA-9939 VS ALKA-9936

ALKA-9936 is a specialist chemical-resistant containment system.

ALKA-9939 is designed around seawater and marine exposure.

Therefore:

Chemical containment / process chemical immersion → ALKA-9936

Seawater splash / tidal exposure → ALKA-9939

LIMITATIONS

ALKA-9939 should not be specified without clearly defining the exposure zone.

Key limitations include:

• Surface preparation remains critical
• Soluble salts must be controlled
• Structural corrosion damage requires repair
• Coating cannot compensate for severe steel section loss
• Cure before seawater exposure is critical
• Direct chemical exposure requires separate compatibility assessment
• Permanent immersion may require a separately approved system
• UV appearance retention should not be assumed from an epoxy barrier finish
• Incorrect DFT can reduce performance
• Pinholes or holidays can compromise the entire barrier
• Marine atmospheric zones may be better served by ALKA-9938

SPECIFICATION GUIDANCE

A complete ALKA-9939 specification should define:

Substrate → Marine Exposure Zone → Steel Condition → Surface Preparation Standard → Surface Profile → Soluble Salt Limit → Edge & Weld Preparation → Stripe Coating → Primer Selection → Primer DFT → ALKA-414 or Approved UHB Epoxy → Number of Barrier Coats → Individual DFT → Total DFT → Recoat Windows → Cure Before Seawater Exposure → Holiday Testing → Inspection → Acceptance Criteria

For piles or marine structures spanning several exposure zones, the specification should clearly identify:

Atmospheric Zone

Splash Zone

Tidal Zone

Immersion Zone

and define where each coating system begins and ends.

SYSTEM POSITIONING

ALKA-9939 should be presented to marine engineers, port authorities, asset owners and protective-coating contractors as:

A severe-duty high-build marine barrier system for steel structures repeatedly exposed to direct seawater splash, tidal cycling and aggressive chloride-rich wet conditions.

Its core value proposition is:

Glass-flake / ultra-high-build barrier + severe seawater exposure protection + project-specific DFT + continuity-focused marine specification + long-term protection for critical splash and tidal assets.

Application Examples

Severe splash and tidal exposure; permanent immersion requires separate project-specific assessment.

Wharf Substructures

Photographic visuals on this page are AI-generated application illustrations, not completed ALKA projects. Colours are illustrative. The system schematic is conceptual and not to scale; refer to current ALKA technical data and project specifications.