Sika FerroGard-950 IN
A two-component, zinc-rich epoxy coating that gives steel and reinforcement the same sacrificial, cold-galvanizing protection as hot-dip zinc — applied by ordinary brush or airless spray on site.
What is it?
A two-component, low-solvent, zinc-rich epoxy primer and protective coating for steel that works as a cold galvanizing compound.
Where is it used?
Structural steelwork, penstocks, gates, pipeline interiors, tanks, and exposed reinforcement bars in concrete repair.
Why use it?
The zinc pigment acts as a sacrificial anode, corroding in place of the steel to deliver galvanic protection comparable to hot-dip galvanizing.
How is it applied?
Blast-clean to Sa 2.5, mix Part A and Part B at 94:6 by weight, then apply by soft brush or airless spray at 0.150-0.250 kg/m2.
About Sika FerroGard-950 IN
Sika FerroGard-950 IN belongs to Sika’s reinforcement corrosion-protection family, but it is not one of the migrating inhibitors like FerroGard-901 or FerroGard-903. It is a two-component, low-solvent epoxy resin loaded with a very high fraction of metallic zinc, and its job is to sit directly on cleaned steel and defend it electrochemically. Once mixed and cured, the dry film carries more than 85% zinc, which turns the coating into an active anode. When moisture and oxygen reach the surface, the zinc corrodes preferentially and the underlying steel stays cathodic and intact. In effect, you are applying galvanizing with a brush or spray gun instead of dipping the member in a molten zinc bath.
That distinction matters on Indian sites, where fabricated members, penstock liners, embedded plates and exposed rebar rarely fit into a galvanizing kettle and often get damaged after the fact by cutting, drilling or transit handling. FerroGard-950 IN lets a contractor restore or create galvanic protection wherever the work happens, including touch-up of scratched hot-dip galvanized surfaces. It can stand alone as a single-coat finish on atmospherically exposed steel, or serve as the anti-corrosive primer beneath a Sikagard protective topcoat in a full paint system. Space Arc Engineering supplies it as an authorised Sika distributor across Delhi NCR and pan-India, with the technical backup to specify it correctly against the job.
The technical insight
The protection is galvanic, not merely a barrier. Zinc sits above iron in the galvanic series, so when the two are electrically coupled in the presence of an electrolyte, the zinc becomes the anode and gives up electrons while the steel becomes the cathode and is spared. FerroGard-950 IN engineers this deliberately: it packs roughly 66% zinc in the wet mix and more than 85% zinc in the dry film, so the cured coating is essentially a continuous mesh of zinc particles in electrical contact with each other and with the substrate. That high loading is what separates a true zinc-rich cold galvanizing coating from an ordinary zinc-pigmented paint. Because the protection is active, minor scratches and pinholes self-heal electrochemically rather than becoming rust initiation points. The corollary is that intimate metal-to-metal contact is essential, which is exactly why blast cleaning to Sa 2.5 is non-negotiable. Any residual rust, mill scale, oil or old coating breaks the electrical circuit and the zinc can no longer polarise the steel.
Where it is used
- Single-coat anti-corrosive finish on structural steelwork exposed to the atmosphere
- Protective primer beneath a Sikagard topcoat in multi-coat industrial paint systems
- Lining and protection of penstock steel liners, gates, weirs and pressure pipeline interiors subject to mechanical wear
- Corrosion protection of exposed reinforcement bars in reinforced-concrete repair
- Repair and touch-up of hot-dip galvanized steel damaged by cutting, punching or drilling
- Restoring galvanic protection to members damaged during transit or erection
- Priming of embedded steel plates, cleats and connections before concreting
- Protection of tank exteriors and fabricated steel that cannot be sent for hot-dip galvanizing
Key advantages
- Delivers active galvanic (sacrificial) protection comparable to hot-dip galvanizing, not just a passive barrier
- Very high zinc loading, with over 85% zinc in the dry film for reliable cathodic action
- Applied by ordinary brush or airless spray, so no galvanizing kettle or off-site processing is needed
- Fast drying and curing keeps site programmes moving, with a tack-free time of about 20 minutes at +30 degrees C
- Strong adhesion to blast-cleaned steel, with tensile adhesion of at least 2.0 N/mm2
- Works as a stand-alone single-coat finish or as a primer under Sikagard topcoats
- Ideal for site touch-up of damaged galvanized surfaces where re-dipping is impossible
- Withstands mechanical wear, making it suited to penstocks, gates and pipeline interiors
Limitations & considerations
- Not suitable for permanent immersion unless protected by a suitable top coat
- Not resistant to strong acids or strong alkalis
- Requires blast cleaning to Sa 2.5 (EN ISO 12944-4), so cleaned steel and the electrical contact it provides are essential to performance
- Application is bounded by conditions: ambient and substrate temperature +8 to +35 degrees C, humidity up to 75%, and substrate moisture below 4%
- Thermal limit of +50 degrees C for permanent dry-heat exposure, and not where simultaneous chemical and mechanical exposure occurs
- Supplied only in pre-batched 2.0 kg units that must be mixed in full, giving no scope to split a pack for very small touch-ups
Selection & best practice
Start with surface preparation, because the whole galvanic mechanism depends on it. Blast-clean the steel to Sa 2.5 per EN ISO 12944-4, or where blasting is not feasible use a rust remover such as Sika Rustoff-100 followed by water-jetting to reach bright, rust-free metal. The substrate must be clean, dry and free of oil, grease and old coatings, with moisture content below 4%. Mix full 2.0 kg units only: disperse Part A with a slow-speed paddle mixer at 300-400 rpm, add all of Part B, mix for two minutes, then decant into a clean container and mix again for one minute, scraping the sides and base. Respect the roughly two-hour pot life at +30 degrees C and only mix what can be used in that window. Apply one or two coats by soft brush, or a single wetting pass by airless spray, targeting 0.150-0.250 kg/m2. Keep ambient and substrate temperature between +8 and +35 degrees C and humidity at or below 75% throughout. When overcoating, allow about one hour at +30 degrees C before a second FerroGard-950 IN coat and about two hours before a Sikagard topcoat, extending both times in cooler weather. Clean tools immediately with Sika Thinner C, since cured material can only be removed mechanically.
Specifications
| Chemical base | Zinc-rich epoxy resin (two-component, low-solvent) |
| Mixing ratio | Part A : Part B = 94 : 6 by weight |
| Packaging | Pre-batched 2.0 kg unit (Part A 1.88 kg + Part B 0.12 kg) |
| Consumption | ~0.150-0.250 kg/m2 (theoretical, before wastage) |
| Zinc content in dry film | > 85% (with ~66% zinc in the mixed wet coating) |
| Density (mixed A+B) | ~2.15 kg/L at +27 degrees C |
| Tensile adhesion strength | ≥ 2.0 N/mm2 on steel, 7 days at +30 degrees C (ASTM D4541) |
| Pot life | ~2 hours (2 kg pack at +30 degrees C) |
| Shelf life | 12 months from production, stored dry between +5 and +35 degrees C |
Industry use cases
Hydropower and water infrastructure
Protects penstock steel liners, gates and weirs against corrosion and mechanical wear where members are too large to galvanize off-site.
Structural steel fabrication
Serves as a site-applied anti-corrosive primer on exposed structural steelwork, connections and embedded plates before topcoating.
Concrete repair and rehabilitation
Coats exposed and cleaned reinforcement bars during patch repairs to arrest corrosion before repair mortar is placed.
Galvanized steel repair
Restores galvanic protection on hot-dip galvanized members damaged by cutting, drilling, punching or transit handling.
Pipelines and storage tanks
Lines pressure-pipeline interiors and protects tank steelwork subject to wear, given a suitable topcoat where immersion applies.
Frequently asked questions
Is Sika FerroGard-950 IN a migrating corrosion inhibitor like FerroGard-903?
How is this different from ordinary zinc primer or a normal anti-rust paint?
Do I really need blast cleaning to Sa 2.5, or can I just wire-brush the steel?
Can it be left as a single coat, or does it always need a topcoat?
How much do I need and how far does one pack go?
What is the working time once mixed, and how soon can I overcoat?
How we position Sika FerroGard-950 IN
Within the Sika range, FerroGard-950 IN is the on-steel, galvanic option and should not be confused with the FerroGard-901 or FerroGard-903 migrating corrosion inhibitors, which are applied to cured concrete surfaces to protect embedded rebar. Pair 950 IN with a Sikagard protective topcoat where a covered, immersed or more chemically demanding finish is required, and reach for Sika Rustoff-100 and Sika Thinner C as the recommended companion rust remover and tool cleaner. In our wider portfolio, contractors doing full concrete-repair sequences often specify 950 IN as the rebar primer ahead of a repair mortar. Where a client prefers the Fosroc system, the closest genuine equivalent is Fosroc Nitozinc Primer, and for concrete repair mortars to follow the priming step we also stock MC-Bauchemie and Dr. Fixit repair systems. Talk to Space Arc for a matched primer-topcoat-mortar specification rather than mixing brands ad hoc.
Fosroc Nitozinc Primer — A specifier standardising on the Fosroc concrete-repair system may prefer Nitozinc Primer, a two-component zinc-rich epoxy primer that pairs naturally with Fosroc Renderoc repair mortars on the same job.
Related Protective Coatings products
Source Sika FerroGard-950 IN for your project
Authorised distribution, technical advice & professional application across Delhi NCR and Pan-India.