STP TankMastic
A single-pack, non-toxic bituminous coating that shields steel and concrete water tanks, pipelines and buried structures from corrosion, acid and alkali attack.
What is it?
A single-pack, solvent-based, unpigmented bitumen coating from STP that dries to a black, taint-free, odourless film for corrosion protection of metal and concrete.
Where is it used?
Inside and outside water storage tanks, on industrial pipelines, conduit pipes, and metallic or concrete structures both above and below ground.
Why use it?
It is economical, easy to brush, roll or spray, tasteless and non-toxic enough for potable water tank coating, and highly resistant to moisture, fresh and salt water.
How is it applied?
Stir thoroughly, apply to a clean, sound, dry substrate by brush, roller or spray at 40-50 microns DFT per coat, and recoat after 12-16 hours.
About STP TankMastic
STP TankMastic is one of those workhorse products that quietly does its job on thousands of Indian projects without much fuss. It is a single-pack, solvent-based bituminous coating that arrives ready to use straight from the tin. There is no pigment, no lead, and nothing to mix on site, which makes it a straightforward choice for site teams who need dependable corrosion protection without a complicated application routine. Once the solvent flashes off, it leaves behind a black, smooth, taint-free bitumen film that seals the substrate against moisture, acids and alkalis. Because that cured film is genuinely odourless and non-toxic, TankMastic has long been trusted for lining the insides of masonry and steel water tanks, including potable water storage, where taste and safety matter as much as protection.
For engineers and contractors across Delhi NCR and the wider country, the appeal is its versatility. The same tin that lines an overhead tank can also protect a below-ground conduit pipe, coat structural steelwork, or waterproof a concrete plinth. It conforms to IS 9862-1981 and IS 158-1981, giving specifiers a recognised reference point when they write it into a bill of quantities. It is not a high-build epoxy or a decorative finish, and it does not pretend to be. What it offers is honest, economical barrier protection that goes on quickly, wets out awkward geometry, and holds up well in contact with fresh or salt water. As an authorised STP channel, Space Arc supplies TankMastic in 1 L, 4 L, 20 L and 200 L packs with technical guidance for the substrate in front of you.
The technical insight
The protection TankMastic delivers is essentially a barrier mechanism rather than a chemical one. Bitumen is naturally hydrophobic, so once the solvent evaporates and the film consolidates, water simply cannot wet the surface it is protecting. That low permeability to moisture is what starves the corrosion cell on steel: without a continuous electrolyte film at the metal surface, the anodic and cathodic reactions that drive rust cannot sustain themselves. On concrete, the same sealing film keeps aggressive water, dissolved chlorides and acidic or alkaline solutions away from the cement matrix and any embedded reinforcement. The formulation is deliberately kept thin-film, with a recommended 40-50 microns dry film thickness per coat, because bitumen coatings that are laid on too heavily tend to skin over on top while the solvent underneath is still trapped, causing wrinkling and very slow through-drying. Building the system up in properly spaced coats, each allowed to dry fully before the next, produces a sounder, better-adhered barrier than one thick pass ever could. The film stays tough yet flexible, so it accommodates minor structural and thermal movement without the brittle cracking that plagues harder coatings.
Where it is used
- Internal lining of masonry and steel water storage tanks, including potable water tanks
- External and internal protection of industrial pipelines and conduit pipes
- Corrosion protection of below-ground metallic and concrete structures
- Anti-corrosive coating for structural steelwork, equipment and machine bases
- Waterproofing and protective coating of concrete surfaces exposed to moisture
- Protection of surfaces in permanent contact with fresh or salt water
- Barrier coating against mild acid and alkali attack on metal and concrete
- General-purpose bituminous priming and protection on maintenance projects
Key advantages
- Single-pack and ready to use, with no site mixing or measuring
- Excellent anti-corrosive protection through a low-permeability bitumen film
- Non-toxic, tasteless and odourless when dry, suitable for potable water tank coating
- Applies easily by brush, roller or spray, wetting out complex shapes
- Bonds to both metal and concrete, above and below ground
- Suitable for surfaces in continuous contact with fresh or salt water
- Resists mild acid and alkali attack as well as moisture ingress
- Economical protection conforming to IS 9862-1981 and IS 158-1981
Limitations & considerations
- Solvent-based and flammable, requiring good ventilation and no naked flames during use
- Must be applied at 40-50 microns per coat; heavy single coats wrinkle and dry very slowly
- Black bituminous finish only, with no colour or decorative options
- Not intended for continuous oil, solvent or heavy mechanical-abrasion exposure once cured
- Requires a maintenance recoat roughly every 2-3 years for continued protection
- Substrate must be clean, sound and below 5% moisture, with a working temperature of +5°C to +45°C
Selection & best practice
Start with the substrate. Clean it thoroughly of dust, oil, grease and any traces of curing compound, and cut out or repair friable or unsound concrete with a proper repair mortar before you coat. Confirm the substrate moisture is below 5% and that both ambient and surface temperatures sit between +5°C and +45°C. Stir the TankMastic well to make it homogeneous, then let it stand briefly so entrapped air can escape. Apply by brush, roller or spray at 40-50 microns DFT per coat, never heavier, and resist the temptation to build thickness in one pass. Allow each coat to dry fully, typically 12-16 hours, before recoating. Do not thin with cheap solvents, as this hurts gloss and drying. Protect the fresh film from oil, chemicals and mechanical stress until it has fully cured, and plan a maintenance coat every two to three years to keep the barrier intact.
Specifications
| Type | Single-pack, solvent-based, unpigmented bituminous anti-corrosive coating |
| Form / Colour | Black, smooth liquid |
| Standards | IS 9862-1981, IS 158-1981 |
| Recommended DFT per coat | 40 to 50 microns |
| Spreading rate | 9-11 m²/L on metal; 6.5-8.5 m²/L on concrete |
| Recoat time | 12-16 hours |
| Touch drying | 3 ± 1 hours |
| Specific gravity | 0.93 ± 0.03 |
| Solid content | 55 ± 2% by weight; 50 ± 2% by volume |
| Flash point | 35°C |
| Pack sizes | 1 L, 4 L, 20 L, 200 L drum |
| Shelf life | 12 months in unopened, sealed packs away from heat and sunlight |
Industry use cases
Water Supply & Storage
Lining the inside of overhead and underground masonry or steel water tanks, including potable water, where a tasteless, odourless, non-toxic film is essential.
Industrial & Process Plants
Protecting pipelines, conduit pipes, equipment and machine bases from corrosion in humid or chemically mild environments.
Infrastructure & Utilities
Barrier coating for below-ground metallic and concrete structures such as buried pipes and culverts exposed to moisture and soil salts.
Marine & Coastal Works
Coating steel and concrete surfaces in contact with fresh or salt water, taking advantage of the film’s water repellence and low permeability.
Building & Maintenance
General-purpose waterproofing and anti-corrosive protection of concrete plinths, steelwork and sumps on repair and refurbishment projects.
Frequently asked questions
Is STP TankMastic safe for potable water tanks?
How many coats do I need and at what thickness?
What is the coverage of TankMastic?
Which standards does TankMastic conform to?
Can I use it on both steel and concrete?
What pack sizes does Space Arc supply and how long does it store?
How we position STP TankMastic
STP TankMastic sits at the economical, general-purpose end of tank and steel protection, and it pairs naturally with the rest of the STP bituminous range for larger scopes; where a project needs a UV-stable exposed membrane rather than a buried bitumen film, STP’s polyurethane and APP-modified membrane systems are the logical step up. Within our wider portfolio, when a client specifies a premium potable-water lining rather than a bitumen coating, we point them to Fosroc Nitocote EP405, a solvent-free epoxy certified non-toxic for potable water and food-contact tanks. For below-grade concrete waterproofing where the coating will be permanently buried, Fosroc Nitoproof 600 is a complementary pitch-modified polyurethane membrane. Our team helps specifiers choose honestly between the economical bituminous route and these higher-spec alternatives based on the actual exposure and approval requirements.
Fosroc Nitocote EP405 — Choose the Fosroc epoxy when a project demands a premium, certified potable-water lining with broad chemical resistance rather than an economical bituminous barrier.
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