MC-Bauchemie MC-Injekt 2300 rapid
The fast-gelling sibling of MC-Bauchemie’s flagship PU elastomer injection resin, built for cracks that will not wait to be sealed.
What is it?
A very low-viscosity, two-component polyurethane elastomer injection resin from MC-Bauchemie – the same chemistry as MC-Injekt 2300 top, formulated to gel in minutes rather than the standard grade’s roughly half-hour working time.
Where is it used?
Injected into active, water-bearing or fast-moving cracks, construction joints, pipe penetrations and manhole ring joints in basements, tunnels, dams, water tanks and sewer infrastructure.
Why use it?
When groundwater is flowing fast or temperatures are low, a resin with a 30-40 minute pot life can wash out of a crack before it gels. Rapid’s roughly 2-minute application time and 4-minute reaction time let it set first, curing to the same permanently flexible, watertight elastomer as the standard grade.
How is it applied?
Pumped through pre-set injection packers using MC-Bauchemie’s one-component pump (MC-I 510) or two-component pump (MC-I 710). Used neat for maximum speed, or blended with MC-Injekt 2300 top’s Component A to dial in an intermediate reaction time.
About MC-Bauchemie MC-Injekt 2300 rapid
MC-Injekt 2300 rapid is the fast-reacting sibling of MC-Bauchemie’s MC-Injekt 2300 top rather than a wholly separate product. Both share the same low-viscosity polyurethane elastomer chemistry, the same 100:111-by-weight (1:1 by volume) A:B mixing ratio, and the same cured properties: a light-brown, permanently elastic resin with close to 100% free strain, adhesive tensile strength around 0.6 N/mm² on dry or wet concrete, and a glass transition temperature near minus 34°C that keeps it flexible well below anything an Indian site sees. What separates the grades is speed. Top gives roughly a 35-minute application window and a 90-minute reaction time; rapid compresses that to around 2 and 4 minutes. The two are fully miscible, so Component A of rapid can be blended into Component A of top in whatever proportion the leak needs, giving a tunable reaction time rather than a fixed one.
This matters most in exactly the situations engineers dread: an active seepage crack in a basement that refills between pumping cycles, a leaking joint in an STP or water tank that cannot be shut down fully, or monsoon-season ingress into a metro shaft where every extra minute of pot life lets water push the resin out before it sets. Rapid is also the standard follow-up after a high-pressure water stop with MC-Injekt 2033 foam, going in as the permanent flexible seal once flow is tamed. Being UBA-compliant for drinking-water contact, it is also specified on potable water tank repairs. Space Arc supplies it alongside the packers, MC-I pumps and MC-Injekt 2033 foam a proper injection job needs, and advises on blend ratios for a given leak and temperature.
The technical insight
Worth knowing before ordering: “rapid” is really an accelerator-grade Component A meant to be blended, not something most sites run 100% neat start to finish. Neat rapid gives the fastest possible set but little margin for mixing and pumping errors, so it suits genuinely fast-flowing leaks or cold weather – MC-Bauchemie sets a firm floor of +6°C below which no 2300 grade may be applied. Most jobs blend a percentage of rapid into top instead. It is also non-foaming and water-displacing, so its volume change on contact with water is a modest ~4%, more predictable in confined cracks than an expanding foam.
Where it is used
- Sealing active, fast-flowing water-bearing cracks where a standard-speed resin risks washing out
- Permanent-seal injection following a high-pressure water stop with MC-Injekt 2033 foam
- Grouting injection hoses, manhole ring joints and pipe penetrations in sewer/STP infrastructure
- Sealing potable water tanks and reservoirs needing UBA drinking-water compliance
- Curtain injection and consolidation of water-bearing soil around foundations
- Cold-weather injection work, where a standard resin’s reaction stretches out further
- Metro, tunnel and underground car park leak sealing without dewatering the structure
Key advantages
- Gels in minutes, resisting washout in fast-flowing groundwater
- Fully miscible with MC-Injekt 2300 top for a tunable reaction speed
- Cures to the same permanently elastic, near-100% free-strain resin as the standard grade
- Non-foaming, controlled ~4% volume change – more predictable than expanding foams
- Compliant with the UBA guideline for contact with drinking water
- Declared performance to EN 1504-5 (U(D1) W(1)) with DIN V 18028 conformity
- Cures reliably under wet, dynamically loaded conditions
- Backed by Space Arc’s local stock and blend-ratio guidance across Delhi NCR
Limitations & considerations
- Very short pot life (~2 min working, ~4 min reaction) demands a trained crew and calibrated pumps
- A flexible sealant, not a structural epoxy – stops water and flexes, does not restore load-bearing strength
- Costs more per litre than MC-Injekt 2300 top, best used where speed is genuinely needed
- Only usable above +6°C substrate/material/air temperature
- Will not bridge large voids or stop very high-pressure gushing water alone – that is MC-Injekt 2033’s job first
- Cannot compensate for poor packer placement – fast cure does not fix bad site prep
Selection & best practice
Run a short trial injection before fixing a blend ratio, since reaction speed shifts with temperature. For most leaks, start with a modest percentage of rapid blended into top’s Component A rather than 100% neat, to keep working time for safe mixing. Where pressure is high, pre-inject MC-Injekt 2033 foam first, then follow with rapid or top for the permanent seal. Use only same-batch components, mix with slow-rotating paddles for the full specified time, and clean tools with MC-Verdünnung PU within the working time – never water.
Specifications
| Chemistry / System | Low-viscosity, two-component polyurethane (PU) elastomer injection resin |
| Mixing ratio (A:B) | 100:111 by weight / 1:1 by volume |
| Density of mixture | approx. 1.04 kg/dm³ (DIN EN ISO 2811-1) |
| Viscosity | approx. 55 mPa·s (DIN EN ISO 3219) |
| Application time (rapid) | approx. 2 minutes, vs. approx. 35 min for MC-Injekt 2300 top (DIN EN 1504-5) |
| Reaction time (rapid) | approx. 4 minutes, vs. approx. 90 min for MC-Injekt 2300 top (ASTM D-7-487) |
| Application temperature | +6°C to +35°C (air, substrate and material) |
| Adhesive tensile strength | approx. 0.6 N/mm² on dry/wet concrete (DIN EN 12618-2) |
| Standards / Approvals | EN 1504-5 Declaration of Performance U(D1) W(1) (1/2/3/4)(6/35); DIN V 18028 certificate of conformity; UBA guideline for drinking-water contact |
Industry use cases
Residential & commercial basements (Delhi NCR)
Stopping an active seepage crack that refills between dewatering cycles during monsoon
Water & wastewater infrastructure (STP/tanks)
Potable-water-compliant crack sealing on a tank or STP structure that could not be taken fully out of service
Metro & tunnel infrastructure
Fast injection into fissures with continuous water ingress, without dewatering the shaft
Sewer & pipeline infrastructure
Sealing manhole ring joints and pipe/liner penetrations against groundwater infiltration
Frequently asked questions
What is the actual difference between MC-Injekt 2300 rapid and MC-Injekt 2300 top?
Can I blend rapid and top to get an in-between set time?
Will it actually stop water that is actively flowing, not just damp?
Is it safe to use in a drinking water tank?
What equipment do I need to apply it?
Can it be used in winter or on a cold basement slab?
How we position MC-Bauchemie MC-Injekt 2300 rapid
MC-Injekt 2300 rapid sits alongside MC-Injekt 2300 top and MC-Injekt 2133/2033 (fast-foaming resins that pre-seal high-pressure water) as one connected system – most real jobs use two or three together. The closest genuine equivalent Space Arc carries from another brand is Fosroc’s Nitofill PU25 LV, a two-component, low-viscosity elastic PU injection resin for the same flexible crack-sealing role; a specifier standardised on Fosroc may reach for that instead, though it lacks MC’s factory-tuned rapid/top blending system.
Fosroc Nitofill PU25 LV — A project team already standardised on Fosroc for its grouting and injection package may pick Nitofill PU25 LV instead, since it plays the same two-component, low-viscosity elastic-PU role, though it does not offer MC’s rapid/top blend system for tuning reaction speed to the leak.
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