Frequently Asked Questions

What is the working time of Nitobond EP after mixing and how large an area should be prepared at one time in Indian summer?

The working time (pot life) of Nitobond EP after mixing the two components together is temperature-dependent: at 25 degrees Celsius, the pot life is typically 30 to 45 minutes — sufficient to apply the bonding agent to a working area and apply the repair mortar or fresh concrete before the epoxy moves beyond the tacky stage. At higher temperatures typical of Indian summer (35 to 40 degrees Celsius ambient), the pot life reduces to approximately 15 to 25 minutes because the elevated temperature accelerates the epoxy cross-linking reaction. The practical implication for site application planning in Indian summer conditions is that the area coated with Nitobond EP in a single mix batch must be limited to what can be covered with repair mortar or fresh concrete within the available pot life — applying the epoxy, then leaving it for 40 minutes before applying the mortar in hot weather risks the epoxy moving through the tacky stage into a partially cured, non-bonding state. Best practice is to work in small sections (10 to 20 square metres per batch in summer), applying the Nitobond EP and immediately following with the repair mortar or concrete overlay application without delay. In very hot conditions (above 38 degrees Celsius), working in the cooler morning hours (before 10 am) and evening hours (after 4 pm) significantly extends the working time and provides more manageable application conditions.

Can Nitobond EP be used in an industrial floor repair where fork-lift and heavy vehicle traffic will cross the repair joint?

Yes — Nitobond EP is specifically well-suited for industrial floor repairs subject to heavy traffic, including fork-lift trucks, reach trucks, and loaded pallet movers, because the high bond strength epoxy bond at the repair-to-slab interface resists the shear and tensile stresses generated by wheel loading and braking across the repair edge. The key failure mode of poorly bonded concrete repairs under fork-lift traffic is interfacial shear failure at the repair edge — the wheel load transitioning from the original slab to the repair patch (or vice versa) generates a differential bending stress at the repair edge that, if the bond at the interface is inadequate, causes the repair edge to delaminate, curl, and ultimately break up under repeated traffic. With Nitobond EP providing a 2 to 4 MPa bond at the interface (equal to or exceeding the tensile strength of normal-grade concrete), this interfacial shear failure mode is eliminated because the bond plane is stronger than the concrete itself — failure under extreme overloading would occur as a crack through the concrete rather than delamination at the repair interface. For industrial floor repairs with Nitobond EP as the bond bridge, the repair mortar used over the Nitobond EP (typically Renderoc S, a cementitious repair mortar, or an epoxy-based repair mortar for the highest floor flatness and surface quality) should be selected to match the design traffic loading, floor flatness requirement, and chemical exposure.

Can Nitobond EP replace Nitobond SBR for all bonding applications or are there situations where Nitobond SBR is more appropriate?

Nitobond EP and Nitobond SBR are both bonding agents for cementitious applications, but they have different performance profiles and cost levels that make each more appropriate for specific applications. Nitobond EP (two-component epoxy) provides bond strength typically 2 to 4 MPa — often higher than the concrete substrate tensile strength, making it the right choice where the highest possible bond is required, where chemical resistance at the bond interface is important, and where the specification calls for a structural bond. Nitobond SBR (single-component styrene-butadiene rubber latex) provides a bond strength typically of 1 to 2 MPa — adequate for most standard repair and topping applications. Nitobond SBR is considerably less expensive, simpler to apply (single component, no measuring or mixing), and has a much longer working life once applied (it can remain in the tacky state for an extended period). For standard concrete repair, screed bonding, and general-purpose repair mortar adhesion, Nitobond SBR is the economical and practical first choice. Nitobond EP is specified where: the bond strength requirement from the structural design exceeds what Nitobond SBR can provide; the interface is subject to chemical attack (oils, acids, alkalis) that would degrade an SBR bond; the concrete substrate is very dense with low porosity and the higher penetrating ability of the epoxy is needed; or where a structural engineer has specifically called for an epoxy bonding agent in the repair specification.