About MC-Bauchemie MC-Injekt 2300 top

MC-Injekt 2300 top is the ductile, flexible member of MC-Bauchemie’s MC-Injekt 2300 injection-resin family — a two-component, low-viscosity polyurethane elastomer built to seal cracks, construction joints and cavities that keep moving. Where a rigid epoxy locks a crack in place, 2300 top cures into a soft, rubber-like fill: roughly 100% free elongation and a glass-transition point around -34°C mean it stretches and relaxes with the substrate through thermal cycling, vibration and minor structural movement, instead of cracking again at the same line. Its viscosity of about 55 mPa·s and low surface tension (34.65 mN/m) let it wick into hairline cracks that thicker resins or cementitious grouts simply cannot enter, and it displaces water from the crack face as it goes rather than foaming and blocking its own path. It carries CE conformity to EN 1504-5 as U(D2) W(1) (1/2/3/4)(5/40) and has German DIBt general building-authority approval both for injection into soil and groundwater and for use in chemically exposed LAU (liquid-hazard storage) facilities — credentials that matter when a consultant or PWD/CPWD engineer wants documented compliance, not just a supplier’s word.

For the Indian market, this is the resin Space Arc reaches for when a basement raft joint, retaining wall, or water-retaining structure (UGT, STP, swimming pool) is leaking under real hydrostatic pressure and the crack is known to be “live” — still opening and closing with temperature or load. It is engineered to work dry, water-bearing, or under pressurised water, so a monsoon-active seepage line doesn’t have to be dried out first. On strongly flowing leaks, MC’s own guidance — and Space Arc’s site practice — is to knock the flow down first with the faster-reacting MC-Injekt 2133, then follow immediately with 2300 top for the permanent, flexible seal. Reaction speed itself is adjustable: mixing in component A of MC-Injekt 2300 rapid shortens set time for cold weather or urgent shutoffs. It is not a retail, DIY product — proper use needs packers, a planned injection concept, ideally a trial injection, and either single-component (MC-I 520) or twin-component (MC-I 710) pumping equipment, which is why it is typically specified through and applied by a trained applicator rather than bought over a counter.

The technical insight

The number that actually does the work here is viscosity: at roughly 55 mPa·s (about the consistency of a light machine oil, tested per EN ISO 3219), combined with a low surface tension of 34.65 mN/m, MC-Injekt 2300 top wets and wicks into crack widths that cementitious grouts and higher-viscosity epoxies physically cannot enter — which is why MC classes it under EN 1504-5’s low-viscosity injectability band (the standard’s “up to 1,000 mPa·s” working-time test threshold). The EN 1504-5 designation U(D2) W(1) is worth reading literally: U(D2) means it’s classified for ductile, elastic sealing rather than rigid structural bonding — confirmed by the ~100% free elongation figure (EN ISO 527) — and W(1) means it’s rated for cracks that are actively moving under water pressure, not just static hairlines. That ductility holds down to a glass-transition temperature of about -34°C (EN ISO 11357-2), which is far colder than any Indian site will ever see — the practical upshot is that the resin stays rubbery, not brittle, across the full range of thermal cycling an Indian basement or retaining wall will experience over its life, so the seal keeps closing and opening with the crack rather than shearing away from one face of it after a few seasons.

Where it is used

• Sealing live, moving cracks in RCC basement walls and rafts under hydrostatic groundwater pressure
• Waterproofing construction and cold joints in water-retaining structures such as STPs, UGTs and swimming pools
• Contact/curtain-style grouting behind lift-pit walls, tunnel linings and retaining structures
• Rising-damp and moisture-ingress cut-off injection in masonry walls
• Sealing pipe penetrations, sleeve connections and manhole ring joints in sewerage and utility structures
• Grouting pre-installed injection tubes and hoses at construction joints
• Permanent flexible follow-up seal after fast-reacting MC-Injekt 2133 has stopped strongly flowing water
• DIBt-approved injection into soil and groundwater, and into chemically exposed LAU containment facilities

Key advantages

• Very low viscosity (~55 mPa·s) and low surface tension give it genuine hairline-crack penetration that thicker epoxies and cementitious grouts cannot match
• Around 100% free elongation keeps the seal intact through seasonal thermal movement and vibration instead of re-cracking along the same line
• Displaces water from the crack face without foaming, so the injection path doesn’t self-block mid-pump
• Reaction time is field-adjustable and can be accelerated with MC-Injekt 2300 rapid component A for cold weather or urgent stop-leak work
• CE-marked to EN 1504-5 (U(D2) W(1)) with DIBt approval for groundwater and LAU chemical-exposure use, giving specifiers an audit-ready compliance trail
• Cures fully even under dynamic/vibration loading, relevant near machine foundations, rail and metro structures
• Comfortable working time (~35 minutes per EN 1504-5, up to ~90 minutes pot life under ASTM D7487-13 depending on batch and temperature) for large multi-packer injection runs
• Low glass-transition temperature (-34°C) keeps it elastic in conditions well beyond what Indian ambient extremes will ever demand

Limitations & considerations

• Needs a calibrated single- or twin-component injection pump (or careful hand-mixing) and trained applicators — not a DIY or brush-on product
• It’s a ductile-elastic sealing resin, not a rigid structural-repair resin; where you need to stitch a static crack back to full load-transfer strength, ask Space Arc about MC’s rigid epoxy injection range instead
• Application must stop once component or substrate temperature falls below 5°C, which matters for early-morning winter work in north India
• Requires a proper leak investigation, injection concept and ideally a trial injection before the main run — this adds planning time and applicator cost versus a surface coating
• Equipment must be cleaned with MC-Verdünnung PU thinner only; water and aqueous cleaners cannot be used, so solvent handling and disposal need to be planned on site
• Pack sizes (1 L multipacks up to 20 L canisters per component) are sized for contractor-scale injection work, not small retail patch repairs

Selection & best practice

Specifications

Industry use cases

How we position MC-Bauchemie MC-Injekt 2300 top

Within MC-Bauchemie’s own injection range, 2300 top is the flexible, permanent-seal partner to MC-Injekt 2133 (the fast-reacting product used to first knock down strongly flowing water) and MC-Injekt 2300 rapid (used as an accelerator additive when set times need to be shortened for cold weather or urgent shutoffs). Where a crack is dormant and needs rigid, load-transferring structural repair rather than a flexible seal, that’s a different job — a rigid epoxy injection resin from MC’s range — and Space Arc can advise which grade fits once the crack has been assessed as live or static. Against third-party alternatives, Fosroc’s Nitofill UR63 is the nearest genuinely comparable option in the Indian market, though it works on a different principle (a water-reactive expanding foam rather than a cured elastomer resin), making it the better call specifically for actively flowing leaks that need an instant hydrophobic block. For rigid, non-moving cracks needing epoxy bonding rather than flexible sealing, Fosroc’s Nitofill LV/EPLV range is the more relevant comparison point, not UR63. Space Arc stocks and applies both the MC-Bauchemie and Fosroc lines, so the practical choice usually comes down to whether the crack is still moving and how the leak is currently behaving on site.

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