STP ShaliDCT 103
Solvent-free processed dehydrated coal tar from STP Limited — the ShaliDCT grade to specify when steel and concrete need durable black anti-corrosive protection with a smoother finish.
What is it?
A single-component, solvent-free processed dehydrated coal tar coating (Grade 103) from STP Limited, formerly sold as ShaliKote CT 103, for anti-corrosive protection of steel and concrete.
Where is it used?
Ship and structural-steel protection, industrial concrete, refractory, graphite and aluminium plants, and timber preservation in marine and chemical-exposure environments.
Why use it?
Delivers a smoother black finish than sibling DCT grades, with strong adhesion and resistance to sea water, oils and chemicals — supplied in 230 kg drums or by bulk tanker.
How is it applied?
Stir at about 400 rpm to a uniform mix, then brush or spray onto blast-cleaned, dry surfaces — two coats on concrete, three on steel; each coat dries within 12 hours.
About STP ShaliDCT 103
ShaliDCT 103 is a single-component protective coating from STP Limited, produced by processing and dehydrating coal tar to a controlled Grade 103 specification. Sold earlier as ShaliKote CT 103, it is a solvent-free material that builds a dense black film with strong adhesion to steel and concrete, and proven resistance to sea water, oils and a wide range of industrial chemicals. Within the ShaliDCT family it is the grade STP recommends where a better surface finish is desired — it carries a higher viscosity than Grades 101 and 102 and levels to a noticeably smoother coat.
The practical case for Indian buyers is straightforward: coal-tar chemistry remains one of the most economical ways to protect steel and industrial concrete in wet, saline or chemically loaded environments, and processed dehydrated tar performs better in this duty than petroleum asphalt. Space Arc Engineering supplies ShaliDCT 103 in 230 kg drums or by bulk tanker across Delhi NCR and Pan-India, with applicator support for shipyards, fabricators and process plants.
The technical insight
The performance of ShaliDCT 103 comes from what is removed as much as what remains. Dehydration strips moisture from crude tar, so the applied film is not undermined by water-vapour blistering, while processing to Grade 103 fixes non-volatile matter at 85 ± 3 per cent — nearly everything you apply stays on the surface as film rather than evaporating. Coal tar’s dense aromatic structure is inherently hydrophobic and chemically stable, which is why the cured coat resists sea water, oils and chemicals without a hardener. A specific gravity of 1.20 and viscosity of 105 ± 25 poise at 30°C give a high-build coat that flows out to the smooth finish this grade is chosen for, and a toluene insolubility capped at 12 per cent confirms a controlled, consistent pitch fraction from batch to batch.
Where it is used
- Anti-corrosive coating for ship hulls and marine steelwork in paint-shop and dry-dock programmes
- Three-coat protective systems for structural steel in fabrication yards and industrial plants
- Waterproof, chemical-resistant black coating on industrial concrete surfaces
- Structures exposed to sea water, oil and chemical splash at ports and jetties
- Coating and process duty in refractory industries
- Applications in graphite manufacturing plants
- Plant protection in aluminium industry facilities
- Preservative treatment of structural and utility timber
Key advantages
- Solvent-free formulation removes the flammable-solvent hazard of conventional tar paints
- Smoother surface finish than sibling ShaliDCT grades — the one to specify where appearance matters
- Excellent adhesion to both steel and properly prepared concrete
- Proven resistance to sea water, oils and a wide range of chemicals
- Performs better than petroleum asphalt tar in equivalent protective duty
- Single component — no mixing ratios, hardeners or pot-life to manage on site
- Applies with an ordinary brush or spray gun and dries within 12 hours per coat
- Bulk tanker supply available for high-volume industrial consumers
Limitations & considerations
- Available in black only — cannot meet decorative or light-colour finish specifications
- Substrate must be completely dry, and new concrete needs a full 28-day cure before coating
- Coal-tar vapours require good ventilation, protective clothing, gloves and eye protection throughout application
- Higher viscosity than ShaliDCT 101/102 makes thorough slow-speed mixing essential and spraying harder in cold weather
- No published coverage rate — plan quantities from a site trial rather than a datasheet figure
- Tools must be cleaned immediately with STP Thinner; the film is difficult to remove once hardened
Selection & best practice
Surface preparation decides the outcome. Remove dust, flakes, oil, grease and loose particles by sand blasting, iron brushing or compressed air, and make sure the substrate is completely dry; new concrete must be at least 28 days old before coating. Stir ShaliDCT 103 with a slow-speed mixer at roughly 400 rpm using a proper mixing paddle until the material is homogenous, taking care not to entrap air. Apply by brush or spray gun — two coats on concrete, three on metallic surfaces — allowing each coat its drying time of up to 12 hours. Clean all tools immediately after use with STP Thinner before the material hardens, and store unused stock in airtight containers in a cool, dry, shaded place away from heat.
Specifications
| Composition | Processed dehydrated coal tar (Grade 103), solvent-free |
| Colour | Black |
| Specific gravity at 30°C | 1.20 ± 0.02 |
| Viscosity at 30°C | 105 ± 25 poise |
| Drying time | 12 hours maximum |
| Non-volatile matter (1 g, 110°C, 3 h) | 85 ± 3% |
| Toluene insolubility | 12% maximum |
| Recommended coats | 2 coats on concrete; 3 coats on steel |
| Packing | 230 kg drum; bulk tanker supply |
Industry use cases
Ports & Marine
Ship hulls, jetty steelwork and splash-zone structures where sea-water resistance is the governing requirement.
Steel Fabrication & Infrastructure
Shop- or site-applied three-coat protection for structural steel heading into aggressive industrial atmospheres.
Metallurgical & Process Plants
Refractory, graphite and aluminium industry facilities that consume coal-tar products for coating and process duty.
Industrial Concrete
Two-coat waterproof, chemical-resistant treatment for plant concrete exposed to oils, chemicals and washdown.
Timber Preservation
Economical preservative coating for structural and utility timber in moisture-exposed service.
Frequently asked questions
How is ShaliDCT 103 different from ShaliDCT 101 and 102?
How many coats do I need?
Is it genuinely solvent-free, and does that change site safety?
What pack sizes can Space Arc supply?
What surface preparation does old steel need?
Is there a Fosroc equivalent to ShaliDCT 103?
How we position STP ShaliDCT 103
ShaliDCT 103 sits in the middle of STP’s coal-tar range: choose ShaliDCT 101 or 102 where a lower-viscosity, general-duty tar is adequate, ShaliDCT 104 for heavier-bodied work, and ShaliDCT 105 where polyurethane compatibility is required. When the specification calls for a two-pack system, ShaliPoxy CTE 103 coal tar epoxy or ShaliKote PU CT coal tar polyurethane give harder, faster-curing films for immersed and pipeline duty. Where coal tar is barred altogether, Fosroc Nitocote EP402 solvent-free epoxy is the concrete-protection alternative we would put forward. Space Arc stocks the full family and can advise grade selection against your exposure conditions.
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