Sika Poxitar F
A tough, immersion-grade two-pack coating that shields buried and submerged steel and concrete in sewage, effluent and marine environments.
What is it?
A two-component, low-solvent epoxy-anthracene oil (epoxy-tar) heavy-duty protective coating from Sika for steel and concrete.
Where is it used?
Buried and submerged structures such as sewage systems, effluent tanks, water-retaining structures, canal linings, marine steelwork and chemical-plant bunds.
Why use it?
It cures to a tough, abrasion-resistant film with excellent resistance to water, seawater and a broad range of chemicals, and can even be applied onto damp concrete.
How is it applied?
Blend Part A and Part B at 85:15 by weight, then apply 2-3 coats by airless spray, brush or roller to build the specified dry film thickness.
About Sika Poxitar F
Sika Poxitar F is a specialist corrosion-protection coating built for the harshest wet and buried service conditions in Indian infrastructure. Chemically it is an epoxy-anthracene oil combination reinforced with mineral fillers, the modern engineered successor to the classic coal-tar epoxy family. What matters on site is the outcome: a tough, hard, heavy-duty film that resists abrasion and impact while shrugging off constant water contact, seawater, diluted acids and alkalis, neutral salts, mineral and fuel oils, grease and detergents. It is the kind of protective layer specified where a coating failure means a shutdown, a leak or an expensive rehabilitation.
The product is deliberately narrow in its intent. It is a black, red-tinted, low-solvent system supplied ready to catalyse, and it is meant for buried and submerged assets such as sewage treatment works, effluent tanks, water-retaining concrete, canal and channel linings, and structural steel below the waterline. One of its most useful traits for Indian sites is tolerance of damp concrete, so casting schedules and monsoon conditions do not stall the protection programme. Space Arc Engineering supplies genuine Sika Poxitar F and, as an authorised applicator, can execute the full surface-preparation-to-topcoat cycle across Delhi NCR and Pan-India. Note clearly that it is not intended for surfaces in contact with drinking water, and not for housing or animal-stable interiors.
The technical insight
The performance comes from the crosslinked epoxy-anthracene oil matrix. When Part B (the hardener) reacts with the epoxy resin in Part A, it forms a dense, three-dimensional polymer network, and the mineral fillers plus the anthracene-oil (tar) fraction close off the film so water and dissolved aggressors cannot migrate to the substrate. Because the film is high-solids (around 87 percent by volume) and builds to 150 microns dry per coat, two to three coats create a continuous, low-permeability barrier rather than a thin decorative skin. That barrier is what delivers the immersion and chemical resistance, and it is also why the film can cure under water and even be applied over damp concrete: the reaction is chemical, not evaporation-dependent, so moisture on the substrate does not stop crosslinking. The trade-off engineers must respect is the low-solvent content: it still carries some solvent, so a freshly coated surface briefly releases solvent into any water it contacts, which is why immediate immersion is only done in special cases and after clearance from the environmental authority.
Where it is used
- Internal and external protection of concrete sewage and effluent treatment tanks
- Lining of water-retaining structures, sumps, canals and stormwater channels
- Corrosion protection of structural steel in buried and submerged service
- Marine and harbour steelwork below the waterline, resisting seawater and barnacles
- Chemical-plant secondary containment bunds and industrial process areas
- Protection of concrete exposed to diluted acids, alkalis and neutral salts
- Coating of damp concrete substrates where a fully dry surface is not achievable
- Barrier coating over pipework and structures handling mineral and fuel oils
Key advantages
- Tough, hard and heavy-duty film with strong abrasion and impact resistance
- Excellent resistance to water, seawater, diluted acids, alkalis and neutral salts
- Withstands mineral and fuel oils, grease and detergents in service
- Can be applied onto damp concrete, ideal for Indian monsoon and tight schedules
- Cures fully even under water, so immersion assets stay protected
- Low solvent content in line with the VdL-RL 04 protective-coatings directive
- Carries a CE mark to EN 1504-2 for concrete surface protection
- High build at 150 microns dry film per coat reduces the number of passes
Limitations & considerations
- Strictly not for surfaces in contact with drinking water, housing or animal stables
- Not resistant to benzene-hydrocarbons or tar oil exposure
- Immediate immersion releases solvent into water and needs environmental clearance
- Short pot life of about 1.5 hours at +20 degrees C demands disciplined batching
- Warm water with a strong temperature gradient can compromise the film
- Black, red-tinted finish only, so it is a functional not decorative coating
Selection & best practice
Success is decided at surface preparation. On steel, blast-clean to Sa 2.5 (ISO 12944-4) with an average roughness depth of at least 50 microns, free of oil and grease; on concrete, remove laitance and friable matter, keep moisture content below 8 percent, and sweep-blast to boost adhesion, which is critical for underwater exposure. Fill large voids and cavities with a compatible Sika mortar before coating. Mix Part A thoroughly, add Part B and blend for at least three minutes including the container sides and bottom, decant and remix briefly. Respect the mixing ratio of 85:15 by weight and thin only the first coat on concrete, and only up to 5 percent Sika Thinner S. Apply by airless spray for the most uniform build (minimum 150 bar, 0.53-0.66 mm nozzle), or use brush and roller with extra passes to reach thickness. Observe the temperature-dependent overcoating window; if the maximum waiting time is exceeded, reactivate the surface by sweep blasting before the next coat. Keep product and substrate temperatures above +5 degrees C and relative humidity under 85 percent, and allow roughly 8-10 days at +20 degrees C for full cure. Always work in protective goggles, gloves and clothing.
Specifications
| Chemical base | Two-component epoxy-anthracene oil combination with mineral fillers |
| Colour / appearance | Black, tinted red |
| Packaging | 35 kg net (combined A + B) |
| Mixing ratio (A:B) | 85 : 15 by weight |
| Density | Approx. 1.8 kg/l |
| Solid content | Approx. 87% by volume, approx. 96% by weight |
| Dry film thickness | 150 microns per coat (2-3 coats typical) |
| Consumption | Approx. 0.310 kg/m² at 150 microns DFT (~3.25 m²/kg) |
| Pot life | Approx. 1.5 hours at +20 degrees C |
| Full cure | Approx. 8-10 days at +20 degrees C with good ventilation |
| Standard | EN 1504-2:2004, DOP with CE mark |
| Shelf life | 1 year in sealed containers, cool and dry |
Industry use cases
Water & Wastewater
Protects concrete sewage and effluent treatment tanks, sumps and water-retaining structures against continuous immersion and aggressive effluent chemistry.
Marine & Ports
Coats submerged harbour and jetty steelwork, resisting seawater, barnacles and abrasion below the waterline.
Chemical & Process
Lines secondary containment bunds and process areas exposed to diluted acids, alkalis, oils and salts in refineries and chemical plants.
Irrigation & Hydraulics
Protects canal linings, stormwater channels and hydraulic structures where damp-substrate application and underwater cure are unavoidable.
Infrastructure Steel
Provides heavy-duty corrosion protection for buried pipelines, penstocks and structural steel in permanently wet ground conditions.
Frequently asked questions
Is Sika Poxitar F safe for drinking-water tanks?
Can it be applied to damp or wet concrete?
What is the mixing ratio and pot life?
How many coats and what thickness are needed?
What chemicals does it resist?
Does Space Arc supply and apply it across India?
How we position Sika Poxitar F
Sika Poxitar F sits at the heavy-duty, immersion end of the protective-coatings range and pairs naturally with other Sika systems on the same programme. Where heavy mechanical exposure is expected on steel, prime first with SikaCor Zinc R before the Poxitar F topcoats; use Sika Thinner S for the permitted first-coat thinning and SikaCor Cleaner for equipment. For levelling voids and cavities on concrete before coating, Sika Poxitar SW Mortar or Icoment-520 Mortar are the compatible repair companions. From our wider portfolio, where a drinking-water contact or solvent-free lining is mandated, a food-grade or WRAS-type epoxy from Fosroc or Dr. Fixit is the correct alternative rather than Poxitar F. For general concrete surface protection above ground, an acrylic or elastomeric anti-carbonation coating is a better fit, keeping Poxitar F reserved for the buried and submerged duties it was engineered for.
Fosroc Nitocote EN901 — A specifier working with strong acids or alkalis across the full pH range, or one needing a solvent-free film with no immersion solvent-release concern, may prefer the Fosroc epoxy novolac over the epoxy-tar Poxitar F.
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Authorised distribution, technical advice & professional application across Delhi NCR and Pan-India.