Product Overview

MC-Nafuplan GP is the general-purpose polyurethane joint sealant in the MC-Bauchemie MC-Nafuplan range — distinct from the high-movement MC-Nafuplan EB (elastic expansion joint sealant with plus/minus 25 percent movement accommodation for large structural expansion joints) by being positioned for the large market of standard construction joint sealing applications where joint movement is moderate and the primary requirement is a durable, flexible, weather-resistant seal that bonds well to concrete, masonry, aluminium, and glass, can be overpainted, and is available in standard construction colours. The single-component polyurethane chemistry of MC-Nafuplan GP cures by reaction with atmospheric moisture and the surface moisture on the joint substrates — the isocyanate functional groups in the prepolymer react with water to form a cross-linked polyurethane elastomer; the single-component nature simplifies application dramatically versus two-component sealants (no mixing, no pot life management, no metering equipment) and provides more consistent results in field application conditions. The cured sealant has Shore A hardness of 20 to 30 (firm but flexible elastic consistency — distinct from the very soft high-movement PU sealants for expansion joints) and tensile adhesion strength above 0.5 to 1.0 MPa to properly primed concrete, masonry, and metal substrates. The movement accommodation of plus/minus 15 to 25 percent of joint width makes MC-Nafuplan GP suitable for joints that undergo moderate thermal and structural movement — typical construction joints that are 10 to 20 mm wide will experience movement of 1 to 4 mm from seasonal temperature cycles — well within the movement capacity of MC-Nafuplan GP. Space Arc Engineering supplies MC-Nafuplan GP for building contractors, facade installers, and finishing contractors in Ghaziabad, Delhi NCR, Noida, and Uttar Pradesh.

Applications

• Window and door frame perimeter joint sealing in external facades — application of MC-Nafuplan GP to the perimeter gap between aluminium, UPVC, or wooden window and door frames and the surrounding masonry or concrete reveals in the external facade of buildings; the perimeter joint sealant must: bond to both the frame material (aluminium, UPVC, wood) and the masonry or concrete reveal; accommodate the differential thermal movement between the metal frame and the concrete or masonry (aluminium has a coefficient of thermal expansion of 23 x 10-6 /degree Celsius versus 12 x 10-6 /degree Celsius for concrete — meaning an aluminium frame 1.2 metres wide has a thermal movement relative to the concrete surround of approximately 1.3 mm over the Indian temperature range of 40 to 45 degrees Celsius); remain watertight and airtight throughout this movement cycle for the service life of the window installation — typically 10 to 20 years
• Wall-floor perimeter joint sealing in wet areas — sealing of the perimeter joint between the wall and floor screed or slab in bathrooms, kitchens, balconies, terraces, and wet utility rooms in residential and commercial buildings; this joint typically opens and closes by 1 to 3 mm from thermal and structural movement and requires a flexible, waterproof, adhesive sealant that prevents water ingress behind the wall tiles or through the floor-wall junction; MC-Nafuplan GP provides a durable seal in this location that outlasts grout (which cracks and falls out of the perimeter joint within 1 to 2 years) and is paintable or tileable
• External facade panel joint sealing in precast and stone cladding facades — sealing of the joints between precast concrete facade panels, natural stone cladding units, large format ceramic or porcelain tiles in external facades, and curtain wall panel joints in commercial buildings where the facade system requires a weatherproof joint sealant that accommodates the thermal expansion and contraction of the cladding units; MC-Nafuplan GP in standard grey, white, or black colour provides an architecturally clean joint seal that can be painted to match the facade colour if required
• General building construction joint sealing — sealing of the numerous small gaps, construction joints, and service penetrations in building construction: gap between precast column and beam at the joint; gap around pipe and conduit penetrations through walls and floors; gap at the junction of different facade materials (brick to concrete, plaster to aluminium, etc.); the versatility of MC-Nafuplan GP in bonding to virtually all clean dry building materials (concrete, masonry, metal, glass, ceramic, wood — with appropriate primer) makes it the standard general-purpose PU sealant for finishing contractors and building maintenance teams

Key Advantages

• Single-component — no mixing, simple caulking gun application — eliminates the mixing errors, pot life management, and specialist equipment required for two-component sealants; any finishing contractor or maintenance operative can apply MC-Nafuplan GP with a standard hand-operated or pneumatic cartridge gun without training on two-component mixing ratios; the consistent quality of single-component sealant is an advantage on Indian construction sites where the skilled labour pool for finishing work is variable
• Paintable — can be overpainted with water-based and solvent-based paints — one of the most commercially important practical properties for building joint sealing; after full cure (typically 24 to 72 hours), MC-Nafuplan GP can be overcoated with standard emulsion paints, masonry paints, epoxy paints, and polyurethane coatings, allowing the sealant joint to be painted to match the surrounding wall or facade finish; silicone sealants — a common alternative — cannot be painted and leave a permanent visible joint that disrupts the painted facade appearance
• Good adhesion to multiple substrate materials with appropriate primer — MC-Nafuplan GP bonds to concrete, masonry, aluminium, galvanised steel, UPVC, and glass with the application of an appropriate PU primer (MC-Nafuplan Primer or equivalent) to the joint faces; the primer activates the surface chemistry for chemical bonding between the sealant and substrate, providing the substrate adhesion required for long-term watertight performance under cyclic joint movement; priming is especially important on smooth non-porous substrates (aluminium, UPVC, glass)
• Weather, UV, and ozone resistance for Indian exterior exposure conditions — the polyurethane chemistry of MC-Nafuplan GP provides good resistance to UV radiation, ozone, and temperature cycling in Indian exterior conditions; UV resistance is important because exterior facade joints receive direct sun exposure, and unprotected sealants without UV stabilisation yellow, chalk, and embrittle within 3 to 5 years in Indian climate conditions; MC-Nafuplan GP maintains its flexibility and adhesion for 10 to 15 years under normal exterior exposure