STP ShaliUrethane PC
A two-component, solvent-free polyurethane tough coating that builds high film in a single spray pass to armour concrete and steel against water, chemicals and abrasion.
What is it?
A 2K, solvent-free, 100% solids aromatic polyurethane protective coating from STP that cures into a thick, tough, chemically resistant film on concrete and steel.
Where is it used?
Water and wastewater pipelines, STP and sewage tanks, storage tanks, reservoirs, marine and offshore structures, penstocks and concrete tunnels.
Why use it?
It delivers very high dry film thickness (1000-1100 microns per coat) in a single wet-on-wet spray pass, with zero VOC and strong resistance to seawater, chemicals and abrasion.
How is it applied?
Airless (plural or single feed) spray onto a ShaliPrime 2PU or 2E LC primed surface, mixed at Component A:B = 3:1 by volume within a short pot life.
About STP ShaliUrethane PC
ShaliUrethane PC is STP’s heavy-duty answer to structures that live in aggressive, wet or submerged service. It is a two-component, solvent-free, 100% solids polyurethane that is spray-applied by airless equipment and cures fast into a thick, resilient, monolithic film. Because it carries no solvent and shrinks negligibly, it can be built to very high thickness in a single wet-on-wet pass rather than the many thin coats a conventional paint would need. That single characteristic is what makes it attractive to pipeline, tank and marine contractors who cannot afford long recoat windows on site.
For the Space Arc audience in Delhi NCR and across India, the coating sits firmly in the protective and anti-corrosion category rather than the decorative one. It is grey, tough and functional, engineered to keep water, effluent, seawater and industrial chemicals from ever reaching the concrete or steel underneath. We supply it in factory packs and, where required, apply it with calibrated airless spray rigs, because the film build and finish this product is capable of depend heavily on correct atomisation, primer selection and substrate condition on the day of application.
The technical insight
The performance of ShaliUrethane PC comes from being a 100% solids polyurethane rather than a solvent-thinned one. In a solvent-borne coating, a large fraction of the wet film evaporates, so the applied thickness collapses as it dries and multiple coats are needed to reach a barrier thickness. Here, effectively all of the applied material stays on the surface and cross-links in place, which is why a single spray pass can reach 1000-1100 microns of dry film. That thick, continuous polyurethane network is what gives the coating its low water-vapour transmission (below 0.27 g/m2 per 24 hours), its resistance to abrasion (45-65 mg loss over 1000 cycles) and its ability to pass 5000 hours of salt-spray at 500 microns. The trade-off to understand is chemistry: this grade is an aromatic polyurethane, which is mechanically and chemically excellent but will gradually change colour under direct, prolonged sunlight. That colour shift is cosmetic only and does not reduce the barrier or mechanical properties, which is why the product is specified where protection, not appearance, is the priority.
Where it is used
- Internal and external lining of potable-water and waste-water pipelines
- Sewage treatment plant tanks, sewer lines and effluent-holding structures
- Steel and concrete storage tanks, reservoirs and overhead tanks
- Onshore and offshore structures, marine piles, ship decks and hulls
- Hydro-electric penstocks, dam gates and thermal power cooling basins
- Concrete tunnels and structures needing a high-build protective barrier
- Coating of pipes for bore and directional-drill installation
- Recoating and repair of existing pipeline and tank coatings
Key advantages
- Builds 1000-1100 microns dry film in a single wet-on-wet spray pass
- Solvent-free and VOC-free, suitable for enclosed and sensitive sites
- 100% solids with negligible shrinkage for a dense, continuous barrier
- Excellent resistance to seawater, most chemicals and acids
- High abrasion resistance and strong adhesion to steel and concrete
- Passes 5000 hours salt-spray and 2000 hours accelerated weathering
- Protects against microbiologically induced corrosion
- Suitable for potable-water and waste-water contact applications
Limitations & considerations
- Aromatic grade will colour-change under prolonged sunlight; use an aliphatic topcoat where appearance matters
- Very short pot life (30-40 minutes for a 100 g sample) demands plural-component spray discipline
- Needs airless spray equipment; not a brush-and-roller DIY coating
- Requires a ShaliPrime 2PU or 2E LC primer for adhesion, not direct application
- Substrate moisture must be below 5% and temperature held between +10 C and +50 C during cure
- Application in rain, ponding or very low temperature can cause incomplete cure and blistering
Selection & best practice
Success with ShaliUrethane PC is decided before the first spray pass. New concrete should be at least 28 days old, clean, dry (moisture below 5%) and free of laitance, oil and loose particles; steel should be prepared and primed as specified. Apply the recommended ShaliPrime 2PU or 2E LC primer and let it surface-dry before coating. Because pot life is only 30-40 minutes, use plural-component airless equipment where possible and never batch more material than can be sprayed in the window. Set tip pressure at 3500-5000 psi with a 32-39 thou orifice to get proper atomisation, and hold substrate and ambient temperature between +10 C and +50 C. Where a second coat is needed for extra thickness, apply it only after the first has surface-dried, and avoid application if rain, ponding or condensation is likely during the cure period.
Specifications
| Composition | 2K solvent-free, 100% solids aromatic polyurethane |
| Colour / Mixing ratio | Grey; Component A:B = 3:1 by volume |
| Recommended DFT per coat | 1000-1100 microns |
| Theoretical consumption | 1.0-1.1 m2 per litre (varies with surface profile) |
| Pot life (100 g sample) | 30-40 minutes |
| Touch dry / Surface dry | 1-2 hours / 5-8 hours |
| Adhesion pull-off | 6-8 MPa on steel; concrete failure on concrete |
| Salt spray / Abrasion | Passes 5000 hrs at 500 microns; 45-65 mg loss over 1000 cycles |
| Packaging / Shelf life | 20 L (15 L A + 5 L B) and 200 L barrels; 12 months at 5-45 C |
Industry use cases
Water and Wastewater
Lines the inside and outside of potable-water and effluent pipelines, sewer lines and STP tanks with a seamless barrier that also resists microbially induced corrosion.
Marine and Offshore
Protects piles, jetties, ship decks and offshore steelwork where constant seawater exposure and abrasion would quickly destroy ordinary coatings.
Power and Hydro
Coats penstocks, dam gates, cooling-tower basins and thermal-plant water structures that need a tough, chemical-resistant film in permanently wet service.
Oil, Gas and Pipelines
Serves as a high-build external coat for bore and directional-drill pipe, and for recoating and repairing existing buried pipeline coatings.
Industrial Storage
Protects steel and concrete storage tanks, reservoirs, mounded bullets and overhead tanks that must hold water or aggressive media without leaching or corrosion.
Frequently asked questions
Is ShaliUrethane PC UV-stable for permanent outdoor colour?
Can it be brushed or rolled, or only sprayed?
Do I need a primer?
How much thickness can one coat achieve?
Is it safe for potable-water and wastewater structures?
What pack sizes does Space Arc supply, and do you apply it?
How we position STP ShaliUrethane PC
ShaliUrethane PC is the high-build protective workhorse within STP’s polyurethane range. Where the priority is a stable, non-yellowing exterior finish over the coating, pair it with the aliphatic ShaliUrethane PU TC 2K topcoat, and always specify the matching ShaliPrime 2PU or 2E LC primer for adhesion. If a spray-applied flexible pipe and tank grade is needed at even higher DFT, ShaliUrethane PC 1000 is the closely related option. Against our other brands, teams that prefer an epoxy-novolac chemistry for extreme acid and chemical immersion should consider a Fosroc lining instead of a polyurethane. Space Arc can advise on the right combination for the specific substrate, exposure and service life required.
Fosroc Nitocote EN901 — A specifier chasing maximum chemical and acid immersion resistance may prefer this solvent-free, 100% solids epoxy-novolac lining over a polyurethane for tanks and secondary containment.
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