Fosroc Nitoprime XG
A two-component, deep-penetrating epoxy primer engineered to lock epoxy floor toppings and repair mortars onto concrete, including damp and moist substrates where ordinary primers fail.
What is it?
Fosroc Nitoprime XG is a two-component, solvent-bearing epoxy primer with strong penetrating properties, formulated to prepare concrete before epoxy floor toppings, screeds and epoxy repair mortars are laid.
Where is it used?
Industrial and warehouse floors, food and pharma plants, basements, plinths and repair zones across Delhi NCR and Pan-India where epoxy systems meet concrete that may carry residual moisture.
Why use it?
It is one of the few epoxy primers that can be applied on damp, moist surfaces, removing the long dry-out delays that stall flooring and repair programmes in humid Indian conditions while delivering a strong substrate-to-topping bond.
How is it applied?
Mix base and hardener in the supplied ratio, apply by brush or roller into clean, sound concrete, then overcoat with the epoxy topping or mortar within the recommended window so the two systems chemically knit together.
About Fosroc Nitoprime XG
Fosroc Nitoprime XG sits in the family of Fosroc surface primers that exist for a single, decisive reason: an epoxy floor or epoxy repair mortar is only ever as good as its grip on the concrete beneath it. Poured concrete is porous, dusty and chemically inert at the surface; a high-build epoxy topping laid straight onto it will sit like a skin rather than a bonded layer, and the first thermal cycle or point load lifts it. Nitoprime XG is the chemical handshake between the two. It is a two-component epoxy primer, meaning a resin base and a hardener that are combined on site and cure by reaction rather than by drying, producing a tough, continuous film that anchors deep into the concrete pores on one face and presents reactive epoxy chemistry to the topping on the other. What distinguishes Nitoprime XG from a conventional primer is its tolerance of moisture. On most Indian sites, concrete is rarely bone-dry; a slab cast a fortnight ago in a monsoon-humid plant still holds residual water, and waiting weeks for it to reach a perfect dry-out is a luxury few schedules allow. Nitoprime XG is formulated to be applied even on damp, moist surfaces, so the flooring or repair crew can prime and overcoat without the multi-day wait that a moisture-intolerant primer would demand. It is supplied and supported in India by Fosroc Chemicals (India) Private Limited from Bengaluru, and Space Arc Engineering, as an authorised Fosroc distributor for Delhi NCR and Pan-India, stocks it as part of the wider Nitoflor and Nitomortar flooring and repair ecosystem.
The technical insight
The performance story of Nitoprime XG is about penetration depth and wetting. Its reported specific gravity of 1.022 g/cc and good penetrating properties point to a relatively low-viscosity, well-wetting formulation that flows into surface capillaries before it gels, mechanically keying into the concrete rather than merely sitting on it. The quoted pot life of 90 minutes at moderate temperature gives applicators a realistic working window to mix, decant and roll a primer coat across a meaningful floor area before the resin-hardener reaction thickens the mix beyond a usable state; in the heat of a North Indian summer that window shortens, which is why the data sheet ties application to a recommended ambient range of roughly 10 to 40 degrees Celsius. The damp-tolerance is the genuinely differentiating property. Standard amine-cured epoxies are sensitive to surface water, which can cause blushing, poor wet-out and adhesion loss; a formulation that bonds reliably on a moist substrate has been engineered to displace or tolerate that water at the interface. Practically, the most important number on any site is not in the data sheet at all – it is the overcoat window. Nitoprime XG must be overlaid with its epoxy topping or mortar while the primer is still tacky and chemically active so the two layers cross-link into one monolithic system; leave it too long and you get a cured-over film that needs mechanical abrasion before the topping will key. Treating Nitoprime XG as a single chemical stage in the flooring build, rather than a separate dried coat, is the core discipline.
Where it is used
- Priming concrete before Fosroc Nitoflor self-levelling and high-build epoxy floor toppings
- Priming substrates ahead of Nitomortar epoxy repair mortars in patch and full-depth repairs
- Bonding epoxy screeds and mortars in industrial, warehouse and process-plant floors
- Preparing damp or moisture-retaining slabs where dry-out time is not available
- Priming plinths, kerbs, equipment bases and bund walls before epoxy protective layers
- Interface coat between sound old concrete and new epoxy overlays during refurbishment
Key advantages
- Bonds on damp and moist concrete, eliminating long dry-out waits on humid Indian sites
- Deep-penetrating formulation mechanically keys into porous concrete for a strong anchor
- Two-component reactive cure produces a tough, continuous primer film rather than a soft dried coat
- Improves adhesion of epoxy floor toppings and epoxy mortars to the substrate, reducing delamination risk
- Generous 90-minute pot life gives a realistic on-site working window
- Simple brush or roller application needing no specialist spray equipment
- Backed by Fosroc India technical support and the matched Nitoflor / Nitomortar system
Limitations & considerations
- Contains solvent, so it requires adequate ventilation and fire precautions during application and cure
- Pot life and overcoat window shorten significantly at high Indian summer temperatures
- Performance depends on a clean, sound, laitance-free substrate – it will not bond to a weak or contaminated surface
- Damp-tolerant does not mean it works through standing water or active hydrostatic pressure; free water and ponding must be removed
- Must be overcoated within the recommended window or the cured film needs mechanical abrasion before topping
- Not a structural, waterproofing or decorative product in its own right – it is strictly an adhesion primer
- Shelf life and full coverage figures should be confirmed against the current Fosroc India TDS for each batch
Selection & best practice
Treat Nitoprime XG as the first stage of the flooring system, not a standalone coat. Begin with proper surface preparation: remove laitance, oil, curing compound and loose material by mechanical means such as grinding or shot-blasting until clean, sound concrete with an open texture is exposed, then remove all dust. Where the slab is damp this is acceptable, but standing water and visible ponding must be removed first – damp-tolerant is not the same as wet-tolerant. Mix the full base and hardener units in the specified ratio using a slow-speed paddle until uniform; never split-batch by eye, as an off-ratio mix will not cure properly. Apply a thin, even coat by brush or roller, working it into the surface rather than flooding it, and decant only what the team can use inside the 90-minute pot life, allowing for faster gelling in summer heat. The critical step is timing the overcoat: lay the Nitoflor topping or Nitomortar repair while the primer is still tacky and reactive so the layers chemically bond into one system. Always confirm mix ratio, coverage, overcoat window and cure times against the current Fosroc India technical data sheet for the batch on site, and respect ventilation and fire-safety requirements for a solvent-bearing epoxy.
Specifications
| Product type | Two-component epoxy primer (solvent-bearing) |
| Primary function | Adhesion primer for epoxy floor toppings and epoxy mortars |
| Specific gravity | 1.022 g/cc |
| Pot life | 90 minutes (at moderate temperature) |
| Recommended application temperature | approx. 10°C to 40°C ambient |
| Substrate condition | Suitable for damp / moist concrete (no standing water) |
| Application method | Brush or roller |
| Penetration | Good penetrating properties into porous concrete |
| Manufacturer | Fosroc Chemicals (India) Pvt. Ltd., Bengaluru |
Industry use cases
Industrial & Warehouse Flooring
Priming green or moisture-retaining concrete slabs so Nitoflor epoxy toppings can be laid on schedule in plants and distribution centres across Delhi NCR without waiting weeks for full dry-out.
Food, Beverage & Pharma Plants
Creating a reliable bond coat beneath seamless epoxy floors in wash-down and high-hygiene areas where slabs are frequently damp and downtime must be minimised.
Concrete Repair & Refurbishment
Priming prepared substrates before Nitomortar epoxy repair mortars in patch repairs to floors, plinths and equipment bases, ensuring the repair does not debond under load.
Basements, Pits & Bunds
Priming damp below-grade concrete in lift pits, basements and chemical bund walls ahead of epoxy protective and screed layers in Pan-India projects.
Automotive & Engineering Workshops
Bonding hard-wearing epoxy mortar screeds onto workshop floors subject to oil, traffic and point loads, where primer failure would lead to rapid topping breakup.
Frequently asked questions
What is Fosroc Nitoprime XG used for?
Can Nitoprime XG really be applied on damp surfaces?
What is the pot life and working time?
How is Nitoprime XG applied?
Which Fosroc products is it used with?
How is it different from Fosroc Nitoprime 25?
Where can I buy Nitoprime XG in Delhi NCR or Pan-India?
How we position Fosroc Nitoprime XG
Nitoprime XG is best understood not as a finished product but as the bond layer that determines whether an epoxy floor or repair survives. Its niche within the Fosroc range is damp-tolerant priming: where Nitoprime 25 is the general-purpose modified-epoxy primer for Nitomortar, Nitoflor and Nitocote systems, Nitoprime XG earns its place on slabs that still carry residual moisture and cannot wait to dry. It should always be specified alongside the Fosroc topping it serves – Nitoflor epoxy floors or Nitomortar repair mortars – because a single-manufacturer primer-topping system gives the most predictable bond. Against competitors, the closest equivalents are Sika’s epoxy bonding primers such as the Sikafloor/Sikadur priming range, MBS (MYK / formerly BASF MBS) epoxy primers within the Mastertop flooring family, and STP’s epoxy primer products; Dr. Fixit, by contrast, is positioned more around waterproofing and is not the natural like-for-like for an industrial epoxy floor primer. Honestly, on substrate moisture tolerance and on schedule compression in humid Indian conditions, Nitoprime XG and its rivals are broadly comparable – the deciding factors are usually which topping system the project has already committed to, local technical support and supply reliability. That is where an authorised distributor matters: Space Arc Engineering recommends matching the primer to the chosen Fosroc topping and confirming substrate condition before specifying, rather than treating any epoxy primer as interchangeable.
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Source Fosroc Nitoprime XG for your project
Authorised distribution, technical advice & professional application across Delhi NCR and Pan-India.