COASTAL INFRASTRUCTURE
Ports & Harbours
Separate coating systems for salt-laden atmosphere, waterfront steelwork and severe splash or tidal exposure.
ALKA PROTECTIVE COATINGS
Different coastal zones demand different protection.
A harbour is not one coating environment. Cranes and warehouse steel above the waterline face salt-laden air, while piles and waterfront structures may face wet/dry cycling and abrasion. ALKA provides distinct system options for these service conditions.
01 / APPLICATION
Marine atmosphere
Cranes, handrails, warehouse steel and jetty structures above the waterline. Prioritise salt resistance and external finish retention.02 / APPLICATION
Splash and tidal exposure
Wharf piles and waterfront surfaces exposed to repeated wet/dry cycling, seawater splash and abrasion.03 / APPLICATION
Demanding maintenance
Existing coastal assets where surface condition, substrate and achievable preparation require a tailored maintenance build.UNDERSTAND THE SERVICE
Specify coastal protection zone by zone.
Salt-laden atmosphere
Crane frames, warehouse steel and elevated structures can be exposed to marine salts while remaining above the waterline. Identify these atmospheric areas separately from surfaces regularly wetted by seawater.Splash, tide and abrasion
Piles and waterfront structures can pass through more than one exposure zone. Mark the boundaries and review wet/dry cycling, mechanical wear and the time available for preparation and cure.Maintenance in a marine setting
Soluble salts, existing coatings and difficult access can affect repair work. Specify contamination removal and acceptance checks, then confirm the preparation and application conditions achievable on site.ALKYD PRIMERS · ENAMELS · SINGLE-PACK FINISHING
A limited role for single-pack ancillary finishes
Dry sheltered workshop equipment, service cabinets and suitable internal fabricated items can be assessed for single-pack primers and enamels. Outdoor port steel often faces salt deposition and persistent moisture, so marine atmospheric and waterfront structures need a separate coating decision.
Products to assess for the job
- ALKA 401 · Alkyd zinc phosphate primerPrepared carbon steel; a corrosion-inhibiting primer for compatible alkyd and enamel finishing routes.
- ALKA 403 · Red oxide anti-corrosive primerA primer option for prepared ferrous metal, fabricated steel and general maintenance; confirm the selected finish compatibility.
- ALKA 410 · Rapid-cure protective enamelA gloss finishing option for machinery, fabricated components and maintenance work over a compatible prepared and primed surface.
Select a complete, compatible primer and finish. The products above are options by role, not a blanket approval to combine every primer and topcoat.
What the applicator or specifier needs
01 · Define the component and dutyDistinguish sheltered internal equipment from salt-exposed external assets. Include salt carried indoors, washing practices and maintenance access in the review.
02 · Prepare and prove compatibilityAssess contamination and retained paint before preparation. Confirm cleaning and substrate condition rather than relying on a new topcoat to cover corrosion.
03 · Plan handling and return to serviceAgree the maintenance interval, finish and repair procedure for the nominated ancillary items. Keep them distinct from the port structural coating schedule.
Write a usable coating schedule
Specify the substrate and preparation, exact primer and finish, individual-coat dry-film thickness, application method, thinning limits, recoat interval and service-cure requirement from current product data. For repainting, document the retained coating and a representative compatibility trial before full application.Choose the coating for the exposure
Single-pack enamel is not proposed for tidal, splash, immersed or severe marine structural duty; use the selected marine or lining system.A single-pack route can simplify small batches and routine repainting because it does not require mixing a separate hardener. It still depends on sound preparation, suitable film build and the correct recoat window. Where exposure or the required maintenance interval is more demanding, assess the relevant two-pack epoxy, polyurethane or specialist lining system.Does fast drying mean the part is ready for service?
No. Touch-dry, recoatable, handleable and fully cured describe different stages. Use the selected product data and actual application conditions to plan each stage. Excessive film build, early overcoating or premature handling can compromise the finish; adding extra thinner or a hardener is not a substitute for the specified application procedure.SYSTEM SELECTION
ALKA systems to consider.
Start with the service conditions, then confirm the complete build for your asset.
| System | Coating build | Nominal DFT | Selection note |
|---|---|---|---|
| ALKA-9938 Marine Atmospheric | Alka 404 zinc-rich epoxy primer → Alka 413 high-build epoxy → Alka 421 polyurethane finish | 275–325 µm | For atmospheric marine exposure only. Tidal, splash and permanent immersion zones require a dedicated high-build lining system. |
| ALKA-9939 Splash / Tidal Zone | Substrate-specific primer → Alka 414 Glass Flake Epoxy or approved Alka UHB epoxy build system | 500–1000 µm | Primer and build vary by substrate. Standard polyurethane topcoats are generally not used as the primary splash-zone barrier. |
| ALKA-9937 Severe Maintenance | Alka 418 MIO glass-flake surface-tolerant epoxy; one or two coats as specified | Nominal 250–600 µm depending on coat schedule | Substrate-specific preparation and primer requirements must be confirmed. Damp-surface or early-immersion use requires written approval. |
DFT = dry-film thickness. Values are nominal selection-guide totals, not wet-film thicknesses or individual-coat application instructions. Use current TDS and written project-specific recommendations.
ALKA-9938 is for marine atmospheric service above the waterline. Splash, tidal and permanent immersion areas require a dedicated approved lining. Damp-surface or early-immersion application needs written technical approval.
FROM EXPOSURE TO SYSTEM
Why these systems are considered.
Use the application and preparation requirements to narrow the options, then confirm the complete specification.
Marine atmospheric steel
The zinc-rich epoxy, high-build epoxy and polyurethane finish is the selection route for above-waterline coastal atmosphere. It should not be carried into tidal or submerged zones without separate approval.Splash and tidal surfaces
The substrate-specific primer and approved glass-flake or UHB epoxy build provide a dedicated route for splash and tidal review. Define the exact service and cure requirements before selecting the build.Demanding coastal maintenance
The MIO glass-flake epoxy option should be assessed against substrate condition, existing coatings and actual service. Do not assume damp-surface application or early immersion is permitted without written approval.SPECIFICATION CHECKPOINTS
Get the details right before coating.
- 01Waterline, splash and tidal boundaries
- 02Soluble salts and surface cleanliness
- 03Abrasion, wet/dry cycling and immersion duration
- 04Substrate preparation, cure and inspection access
THE SYSTEM APPROACH
Define the service environmentSeparate atmospheric, splash, immersion and chemical zones.
Select the complete coating buildConfirm substrate preparation, primer, barrier or lining and finish.
Verify before return to serviceRecord film thickness, cure and project-specific inspection results.
A lining specification must address the full exposure regime, including cleaning and intermittent upset conditions.
Confirm surface preparation, stripe coating, application conditions, recoat intervals and cure. Record inspection results against the approved coating schedule.
APPLICATION & QUALITY PLANNING
Build inspection into the specification.
Agree the acceptance criteria before work starts, with the current product data and project coating schedule as the reference.
01 · Accept the substrate
Record substrate condition, cleanliness and the specified surface preparation. Resolve contamination, unsound existing coatings and detailing before the first coat.02 · Control application
Confirm environmental limits, mixing, usable application time and recoat windows from the current product data. Record coating batches and the conditions during each stage.03 · Verify the complete build
Check coverage at edges and details, specified individual-coat thickness and total dry-film thickness. Define how defects will be repaired and re-inspected.04 · Release to service
Document exposure boundaries, salt-removal checks, coating thickness, repair locations and the approved time and conditions for water contact.TECHNICAL QUESTIONS
Details that change the specification.
Can one system run from the top of a pile to below water?
Only if the complete build has been specifically approved for every exposure involved. Normally the specification should identify atmospheric, splash, tidal and immersion zones and detail any transition between systems.Is a polyurethane finish the main barrier in a splash zone?
A polyurethane atmospheric finish should not be assumed to provide the primary splash-zone barrier. Select the approved lining or high-build epoxy system for that duty and confirm any additional finish separately.Can a coated asset be immersed as soon as it feels dry?
No. Immersion release depends on the approved product, applied build, curing conditions and inspection results. Plan the full cure period and obtain specific approval for any proposed early immersion.TECHNICAL RESOURCES
Move from selection to specification.
Coating system library
Compare ALKA system builds for atmospheric, maintenance and lining applications.Browse systems →Product information
Explore product information and request current technical and safety data sheets.Technical information →Specification support
Confirm preparation, products, film thickness and service conditions with ALKA.Contact technical team →SPEAK WITH THE MANUFACTURER
Specify the right protection.
Send the substrate, exposure, existing coating condition and required finish. Our technical team can help identify a suitable ALKA system and the information needed for your specification.System selection is subject to current product data and written project-specific confirmation. Sector images are illustrative.