Overview
The specialty range covers the coatings that do not fit neatly into a general category: marine systems for hulls and offshore structures, acid and alkali proofing linings, underwater curing coatings, antifouling, waterborne systems and the high-build primers built for severe corrosion service.
These are the products that solve a specific, difficult problem. A ballast tank coating has to survive immersion in seawater with a very high electrolyte conductivity. An antifouling has to poison the organisms that attach to a hull and stay effective at speed. An underwater curing coating has to harden on a submerged, cold, wet steel surface. Each needs its own chemistry, its own preparation standard and its own inspection regime.
For these systems the product data sheet is not guidance, it is the specification. Surface preparation, film thickness, curing conditions and the acceptance test are all part of the product's performance claim, and deviating from any of them voids it.
Moisture-Cure High-Build Epoxy Zinc-Rich Primer: Single-component
Product identification
The identifiers below are the ones printed on the drum and quoted on the purchase order. Always order and dispatch by code, because the grade and the zinc or temperature variant cannot be inferred from the trade name alone.
| Product code | GH900 |
|---|---|
| Trade name | Moisture-Cure High-Build Epoxy Zinc-Rich Primer |
| Category | Specialty coatings |
| System role | Zinc-rich primer - sacrificial corrosion protection |
| Manufacturer description | Single-component |
Where this product is used
- Ship hulls, ballast tanks, cargo holds and shipboard structures
- Offshore platforms, risers, jackets and topside equipment
- Acid and alkali resistant linings in chemical process plants
- Underwater structures, pipelines and submerged repair work
- Yacht hulls and underwater coatings
- High-pressure pipeline internal linings
- Waterborne systems for corrosion control in sensitive environments
- Chemical resistant tank and bund interiors
How it works in the coating system
A zinc-rich primer protects steel by two mechanisms at once. The zinc powder in the film corrodes preferentially to the steel, protecting it cathodically even where the coating has been damaged through to bare metal, and the epoxy binder forms an impermeable barrier over the rest of the surface.
That sacrificial protection is what makes zinc-rich epoxy the standard primer for any steel in a corrosive atmosphere. The higher the zinc loading, the more sacrificial protection the film provides and the more current is required to dissolve the zinc — which is why the zinc content percentage is specified precisely rather than described qualitatively.
Purpose in the system: Applied directly to the prepared steel substrate, followed by an intermediate coat and a topcoat.
Technical properties
The values below are the typical published range for this product family. The exact figures for your batch are confirmed on the batch certificate and the current technical data sheet.
| Role in the coating system | Specialised coating for a defined service environment |
|---|---|
| Volume solids | 50–100 % |
| Mixing ratio by volume | 4:1 or 5:1 by volume for two-pack grades; single component where stated |
| Typical dry film thickness | 60–300 µm per coat depending on the grade |
| Theoretical coverage | 3–12 m²/litre per coat |
| Application methods | Airless spray · conventional spray · brush · roller |
| Application temperature window | 5–40 °C, minimum 3 °C above dew point |
| Suitable substrates | Prepared steel, concrete, tank internals and marine structures |
| Finish / appearance | Full colour range; matt or semi-gloss |
| Principal resistance | Corrosion, immersion, chemical attack, abrasion or fire, depending on the grade |
| UV resistance | Varies by grade — check the specific data sheet |
| Adhesion to prepared steel | > 4 MPa pull-off on prepared steel |
| Salt spray performance | > 2,000 h for the marine and offshore grades |
| Chemical resistance | Varies from general chemical resistance to acid and alkali proofing |
| Abrasion resistance | Good to excellent in the abrasion-resistant grades |
| Flash point | Not applicable (water-based) to 30 °C |
| Shelf life | 6–24 months unopened |
| Density | 1.05–1.60 g/cm³ |
| Pack sizes | 1 kg–25 kg kits; 200 kg drums |
Surface preparation
- Determine the exact service environment first — immersion, splash zone, atmospheric, chemical, temperature and the mechanical wear expected — and select the coating from the service environment, not from the generic product name.
- Abrasive blast steel to the standard stated in the product data sheet, which is normally Sa 2½ but may be Sa 3 or St 3 for specific products. Record the blast profile and anchor pattern.
- Test for soluble chlorides and wash with fresh water where contamination is likely, particularly on marine and offshore work.
- Carry out holiday detection on the completed coating and repair every defect before the coating is accepted.
- Confirm ambient conditions — substrate above the dew point by 3 °C, temperature above 10 °C and humidity below 80% — against the product's stated application window.
- For underwater or immersed work, use the specifically approved underwater curing grade and verify the substrate is clean of marine growth and loose scale.
Application procedure
Apply by airless spray for maximum film build without solvent entrapment, or by conventional spray, brush or roller for smaller areas.
The wet film must be applied heavily enough to hold the zinc powder in suspension. Under-application leaves the zinc settled and the film effectively under-strength.
Observe the minimum overcoating interval even when the primer appears dry — zinc-rich films continue to cure and outgas for some time.
Mixing, ratio and induction time
Typically mixed 4:1 or 5:1 by volume. Mix thoroughly with a high-shear mixer or a power tool until the zinc paste is fully dispersed and the mix is a uniform grey. A poorly dispersed zinc-rich primer will have patches with no zinc at all, which then corrode faster than bare steel.
Cure, recoat window and service readiness
Recoatable after 6 to 24 hours depending on grade, temperature and film thickness. Full cure takes 7 days. Do not exceed the maximum overcoating interval — if the primer has cured past that point, abrade it and re-clean before overcoating.
Coverage and thickness calculation
Typical dry film thickness is 60-80 µm. Zinc loading runs from 30% to 80% by weight, and each grade has a matching price, appearance and protection level. Quote the grade, not just 'zinc-rich', because the zinc percentage is what defines the performance.
Technical note. Coverage (m²/litre) = (volume solids × 10) / DFT (µm)
Worked example
| Specified DFT | 150 µm |
|---|---|
| Volume solids | 70 % |
| Theoretical coverage | 4.67 m²/litre |
| Total for the area | 100 m² → 466.7 litres |
Advantages
- Products engineered for severe service — ballast tanks, chemical immersion, splash zones and underwater repair.
- Certification available for ship classification and potable water where the grade requires it.
- Specialised chemistry for genuinely difficult problems such as underwater curing and static conductivity.
- High-build formulations that deliver long service life in corrosive atmospheres with fewer coats.
- Waterborne options for sites with strict VOC limits or occupational exposure controls.
- Full coating systems available from a single manufacturer, which removes compatibility risk between coats.
Limitations and precautions
- Each product has a narrow, defined application window and is not interchangeable with a superficially similar product.
- Failure to follow the specified preparation, film thickness and curing conditions voids the performance claim.
- Marine and offshore work requires access, weather windows and specialist application equipment.
- Some specialty grades are expensive and the volumes required may not justify the cost on small projects.
- Chemical resistance ratings assume the stated concentration and temperature; exceeding either invalidates the selection.
Storage and shelf life
- Store component A and B in their original sealed containers in a cool, dry, ventilated store between 5 °C and 30 °C.
- Protect from freezing and direct sunlight, and keep containers tightly closed.
- Do not store two-pack components next to strong oxidisers or solvents.
- Rotate stock first-in-first-out and observe the labelled shelf life.
Safety, PPE and ventilation
- Use full respiratory protection, chemical-resistant gloves, goggles and protective clothing for all application work.
- Ensure excellent ventilation; offshore and confined-space applications require atmospheric testing before entry.
- Keep ignition sources away from solvent-borne grades.
- Follow the product's specific safety data sheet — marine and antifouling grades may carry additional handling requirements.
- Collect all waste and dispose of it through a licensed contractor.
Quality control and inspection
- Verify the zinc percentage of the batch against the specification and check the batch certificate.
- Record the batch mixing ratio and the induction time for every mix.
- Holiday test and measure DFT before overcoating, paying particular attention to welds and edges where film build is usually thin.
Pricing and how to order
Delshine quotes this product per square metre at a specified dry film thickness, or per drum/litre depending on the project. The material cost is usually the smallest part of the installed cost — surface preparation, access and application labour dominate. Send us the substrate, the service conditions and the required DFT and our technical team will return a full system recommendation with a firm price.
Specialty and marine coatings are quoted per square metre at a specified dry film thickness, normally as a complete system. On offshore and marine work, the preparation and access costs are frequently larger than the coating cost itself, so always specify preparation, holiday testing and inspection explicitly in the contract scope.
Frequently asked questions
The questions below are the ones our technical team is asked most often about this product family.
What is underwater curing coating and when is it used?
Underwater curing coatings are formulated to harden on a submerged, cold, wet steel surface where conventional epoxy cannot cure because it needs oxygen and warmth. They are used for offshore structural repair, pipeline repair clamps and any situation where the steel cannot be dried. The underwater curing anticorrosive coating in the Delshine range is designed for exactly this application.
What is antifouling paint and how does it work?
Antifouling prevents marine organisms — barnacles, algae, molluscs — from attaching to a hull underwater. Traditional copper-based antifouling works by leaching biocides from the film; self-polishing antifouling goes further and sheds a biocide-containing layer as the vessel moves, keeping the surface clean for the life of the coating. Application, thickness and hull preparation all follow strict specification.
Which coating should I use in a ballast tank?
A ballast tank coating must resist seawater immersion with a very aggressive electrolyte, and it must be able to withstand movement and vibration of the vessel. The modified epoxy ballast tank anticorrosive coating in the range is specified for this service, in grey, with a defined preparation standard and acceptance test.
What is a static-conductive coating?
It is a coating that conducts electricity to earth at a controlled rate, dissipating static charge that would otherwise build on equipment and create a spark. It is used in fuel tank interiors, pharmaceutical cleanrooms and areas handling flammable materials. Unlike an antistatic coating, which limits charge build-up, a static-conductive coating has a defined low surface resistance and requires an earth connection to work.
How do I select the right coating for chemical immersion?
List the chemicals, their concentrations and the operating temperature, then select a coating whose published resistance table covers all three. Phenolic epoxy is the standard answer for strong acids, vinyl ester for a broad acid and alkali range, and epoxy coal tar for petroleum products. If the combination is not covered by a published table, ask the manufacturer to test — do not assume compatibility.
Can a specialty coating be applied in the field?
Many can, provided the preparation, ambient conditions and film thickness match the specification. Field application is routine for offshore maintenance, provided the surface is prepared to the required standard and the application is inspected. Where the product's certification depends on controlled factory application, check the certificate before specifying a field-applied system.
Related products
These products are normally used in the same system as the product described above.
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