Master Builders Solutions MasterEmaco P 130
Two-component zinc-rich epoxy primer that puts sacrificial protection on exposed reinforcement — over 84% zinc in the dry film, tack-free in 25 minutes, ready for repair mortar the same day.
What is it?
A two-component, solvent-borne zinc-rich epoxy primer for steel, supplied as a thick grey liquid. With more than 84% zinc by weight in the dry film, it works galvanically — the zinc corrodes in preference to the steel it coats.
Where is it used?
On exposed reinforcement in concrete patch repairs, on structures attacked by chlorides (coastal, marine, industrial), as touch-up on damaged galvanised metal, and as a primer on steel before a compatible topcoat.
Why use it?
Ordinary primers only block moisture; a pinhole becomes a corrosion cell. P 130 protects actively — even where the film is imperfect, the zinc sacrifices itself and the rebar stays passive until the repair mortar goes on.
How is it applied?
Brush-applied on grit-blasted or wire-brushed dry steel. Mix base to hardener 4:1 by volume, coat the full bar including the back face at over 50 microns per coat, and overcoat with repair mortar once dry — typically 6-8 hours at 25°C.
About Master Builders Solutions MasterEmaco P 130
MasterEmaco P 130 (formerly Concresive ZRi) is the reinforcement primer in the Master Builders Solutions concrete repair system. When cover concrete spalls and rebar is exposed, the steel loses the high-alkalinity environment that kept it passive — and simply burying it in fresh mortar does not deal with chloride already sitting on the bar. P 130 is brushed onto the cleaned steel first, loading the surface with metallic zinc so the bar is electrochemically protected before, during and after reinstatement. It is formulated to meet the scope of BS 4652 Type 2 and is the specified rebar primer ahead of MasterEmaco repair mortars.
For Indian repair practice the working times matter as much as the chemistry. The material is tack-free in 25 minutes at 25°C — just 10 minutes at 40°C — so a crew can prepare bars in the morning, prime, and place repair mortar the same day instead of losing a shift waiting on the primer. Space Arc Engineering stocks and supplies MasterEmaco P 130 as an authorised Master Builders Solutions distributor and applicator across Delhi NCR and Pan-India, and can support quantity take-offs from the rebar-diameter coverage table so sites order the right number of 1-litre units.
The technical insight
The protection is galvanic, not just physical. Zinc sits below steel in the electrochemical series, so when the two metals are electrically connected in the presence of moisture, zinc becomes the anode and corrodes preferentially while the steel cathode stays intact — the same principle as galvanising. That only works if zinc particles actually touch each other and the steel, which is why the dry film carries more than 84% zinc by weight: at lower loadings the particles float isolated in resin and the coating degrades into a plain barrier. The epoxy binder contributes adhesion to the blasted steel and holds the zinc in intimate contact with the bar. The practical consequence on site is tolerance: a barrier coating concentrates attack at every pinhole and brush-miss, whereas a zinc-rich film sacrifices itself at those defects and the bar underneath stays protected. Because the zinc is consumed over time, the film is not a permanent finish — the TDS is explicit that overcoating with mortar or a topcoat should follow as soon as practical, particularly in aggressive exposures.
Where it is used
- Priming cleaned, exposed reinforcement in concrete patch repairs before MasterEmaco repair mortars
- Protecting rebar in chloride-affected structures — marine berths, jetties and coastal buildings
- Rehabilitation of bridge and flyover elements where carbonation or chlorides have corroded reinforcement
- Repair of spalled columns, beams, slab soffits and chajjas in ageing buildings and housing stock
- Touch-up priming of damaged or welded galvanised metal — handrails, cable trays, fasteners
- Priming steel substrates prior to a suitable, compatible topcoat
- Rebar protection in industrial structures — cooling towers, chimneys, ETP/STP tanks — during structural repairs
Key advantages
- Active sacrificial protection of the steel, not merely a passive moisture barrier
- Over 84% zinc by weight in the dry film ensures true galvanic continuity with the bar
- Tack-free in 25 minutes at 25°C and recoatable in 6-8 hours, keeping repair cycles to a single day
- 120-minute pot life at 25°C gives brush crews time to work around congested reinforcement
- Excellent adhesion to grit-blasted or wire-brushed steel
- Brush consistency reaches the back face of bars where spray coating misses
- Repair mortar can be placed as soon as the primer is dry — direct compatibility with the MasterEmaco system
- Formulated to meet the scope of BS 4652 Type 2
Limitations & considerations
- Not a finished coating — the zinc is consumed over time, so overcoat with mortar or a topcoat as soon as possible, especially in aggressive environments
- Performance depends on surface preparation: steel must be grit-blasted or wire-brushed to clean, dry metal, free of oil, grease and dust
- Solvent-borne system — ventilation, no ignition sources, and MSDS handling precautions apply, particularly in confined repair zones
- Application window is 10°C to 40°C substrate/ambient temperature
- Shelf life is six months, and in tropical Indian conditions stock must be kept in air-conditioned storage
- It protects remaining steel but does not restore lost bar section — heavily corroded reinforcement needs structural assessment and possibly supplementary bars
Selection & best practice
Prepare the steel properly and prime it immediately — those two steps decide the outcome. Grit-blast or wire-brush the bars to remove every trace of rust, then check for oil, grease and dust; the surface must be dry. Never leave prepared steel overnight uncoated: it starts re-rusting within hours. Stir each component, add the hardener to the base at 4:1 by volume and blend with a slow-speed drill and mixing paddle. Brush the primer over the full bar circumference, paying deliberate attention to the back face against the concrete — this is the surface crews most often miss. Aim for a continuous film above 50 microns; where continuity is in doubt, apply a second coat immediately after the first has dried. On a 1-litre unit, expect roughly 140-175 running metres per coat on 12 mm bars, dropping to 55-65 m on 32 mm bars. Place the repair mortar as soon as the primer is dry — 6-8 hours at 25°C, 2-4 hours at 40°C — and clean tools with Cleaning Solvent No. 2 straight after use.
Specifications
| Form / appearance | Two-component, solvent-borne zinc-rich epoxy; thick grey suspension |
| Total zinc content in dry film | >84% by weight |
| Mixed density | 2.9 ± 0.1 kg/litre |
| Volume solids | 57 ± 3% |
| Mixing ratio (by volume) | 4 parts base : 1 part hardener |
| Pot life / tack-free time | 120 minutes / 25 minutes at 25°C (tack-free 10 minutes at 40°C) |
| Recoat / overcoat time | 6-8 hours at 25°C; 2-4 hours at 40°C |
| Dry film thickness and coverage | >50 microns per coat; 8-10 m² per 1-litre pack per coat on smooth substrates |
| Standard, packing and shelf life | BS 4652 Type 2; 1-litre combined unit; 6 months in cool, covered storage |
Industry use cases
Bridges & Flyovers
During deck, pier and girder rehabilitation, exposed bars are primed with P 130 after blasting so chloride-contaminated members get galvanic protection before MasterEmaco mortars reinstate cover.
Marine & Coastal Structures
Jetties, wharves and seafront buildings carry chloride loads that restart corrosion under fresh patches; the sacrificial zinc film keeps repaired bars passive in exactly these exposures.
Industrial Plants
Cooling towers, chimneys, bunkers and effluent treatment tanks combine moisture with aggressive chemistry — rebar in structural repairs is primed before reinstatement to extend repair life.
Buildings & Housing Rehabilitation
Spalled balconies, chajjas, slab soffits and column jackets in ageing residential and institutional stock are the highest-volume use: small 1-litre units suit scattered patch repairs.
Water & Wastewater Infrastructure
WTP/STP structures under repair get bars primed with P 130 ahead of mortar reinstatement, with a compatible protective topcoat completing the system on exposed faces.
Frequently asked questions
Why use a zinc-rich primer on rebar instead of a plain epoxy or cement slurry?
How much MasterEmaco P 130 do I need for a repair job?
How soon can repair mortar be applied over the primer?
Can the primed steel be left exposed without a topcoat or mortar?
Is one coat enough, or should I apply two?
Can I apply it over rusted or damp bars to save preparation time?
How we position Master Builders Solutions MasterEmaco P 130
MasterEmaco P 130 is the first material in the Master Builders Solutions repair sequence: prime the steel, reinstate the section with a MasterEmaco repair mortar suited to the member and thickness, and finish exposed faces with a protective coating where the exposure demands it. Specifying all layers from one system keeps compatibility and warranty conversations simple. Where the project is already standardised on Fosroc, the equivalent role is filled by Nitoprime Zincrich Plus working under Renderoc repair mortars — Space Arc supplies and supports both systems, so the sensible choice is usually whichever repair mortar family the consultant has specified, with the matching primer from the same brand. For advice on batching primer quantities against your bar schedule, or on pairing P 130 with the right MasterEmaco mortar grade, our technical team works with contractors and consultants across Delhi NCR and Pan-India.
Fosroc Nitoprime Zincrich Plus — Specifiers running a Fosroc Renderoc repair system — or crews that prefer a single-pack zinc primer with no on-scaffold mixing — typically choose Nitoprime Zincrich Plus for the same sacrificial rebar-priming role.
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Authorised distribution, technical advice & professional application across Delhi NCR and Pan-India.