About MC-Bauchemie Donnitil 3-X

On any active RMC yard, precast unit or facade job in Delhi NCR, cement and mortar residue is a daily nuisance rather than an occasional one — transit mixer drums cake up, casting beds lose their release, and grout haze dulls a freshly laid clinker or ceramic facade right before handover. The default fix on most Indian sites is still a bucket of diluted muriatic (hydrochloric) acid and a wire brush, which works but comes with fumes, splash burns, corroded rebar and steel fittings, and etched or discoloured finishes when it’s used a shade too strong or left on a shade too long.

Donnitil 3-X is MC-Bauchemie’s answer to that trade-off. It swaps liquid hydrochloric acid for sulfamic acid — a solid, low-fume acid that is inherently easier and safer to store, transport and dose as a powder — and pairs it with tetrapotassium pyrophosphate, which keeps the dissolved calcium in solution instead of redepositing as a dull film once the surface dries. The result is a cleaner that a site team can mix to the strength the job actually needs, apply with a short soak rather than prolonged scrubbing, and rinse away cleanly, making it as much a productivity tool for keeping plant and moulds turning over as it is a cosmetic finishing step for concrete, brick and ceramic surfaces.

The technical insight

The chemistry is straightforward once you see the two active ingredients doing separate jobs. Sulfamic acid (sulphamidic acid, CAS 5329-14-6) makes up the bulk of the formulation and reacts with the calcium carbonate and hydrated lime in cured cement to form water-soluble calcium sulfamate, which is what lifts the hardened film off the substrate. Unlike hydrochloric acid, sulfamic acid is supplied and stored as a stable crystalline solid, so it doesn’t off-gas corrosive fumes in the drum or generate the same chloride-ion risk to embedded steel that repeated muriatic-acid washdowns can cause near reinforcement or exposed rebar. Tetrapotassium pyrophosphate, present at 10–30% of the mix, acts as a sequestering agent — it binds the calcium and other metal ions the acid dissolves so they stay suspended in the rinse water instead of re-precipitating as a white haze on the surface once it dries, which is the usual complaint with cheaper single-acid cleaners. A small proportion of disodium disulphite rounds out the formulation as a stabiliser. Per its safety data sheet, the finished powder is a whitish solid with a density of 2 g/cm³ at 20°C, fully soluble in water and dilutable up to 1:20, and is classified Skin Irrit. 2 / Eye Irrit. 2 / Aquatic Chronic 3 under GHS — mild by acid-cleaner standards, but real enough that PPE and controlled rinsing are non-negotiable.

Where it is used

• Cleaning transit mixer drums, pump lines, chutes and hand tools of hardened concrete and mortar splashes
• Stripping cement film and laitance from precast moulds and casting beds between pours
• Cleaning washed / exposed-aggregate concrete finishes after formwork strike
• Removing cement haze and grout smear from clinker brick and ceramic facade installations after laying
• Spot-treating efflorescence and cement streaks on finished masonry or plaster ahead of painting
• Post-pour housekeeping of hardstands, ramps and site access roads where concrete has spilled or splashed
• Preparing shuttering and formwork panels for reuse by clearing built-up laitance
• Turnaround cleaning of hired concrete pumps, mixers and tools between site deployments

Key advantages

• Powder concentrate is lighter, more compact and safer to store and transport than drums of liquid acid
• Dilutable up to 1:20, so one pack of powder stretches across many cleaning cycles, keeping running cost down
• Short soaking time means equipment, moulds and formwork are back in service faster
• Sulfamic-acid base is a low-fume, solid acid — easier and safer to dose on site than concentrated muriatic acid
• Built-in sequestering agent (tetrapotassium pyrophosphate) helps prevent the dissolved residue from redepositing as haze after rinsing
• Fully water-soluble and rinses clean, leaving no oily or waxy film behind on the substrate
• One product handles concrete, clinker brick and ceramic facings, avoiding a separate cleaner for each surface
• Comes with a documented, current SDS under UK REACH / GHS classification, useful for site safety and JSA paperwork

Limitations & considerations

• It is an acid-based cleaner classified Skin Irrit. 2 / Eye Irrit. 2 — gloves, goggles and acid-resistant clothing are mandatory, not optional
• Not suited to acid-sensitive surfaces — natural stone (marble, limestone), polished terrazzo and unprotected metals can etch, dull or corrode
• No India-specific technical data sheet, dosage chart or pack-size list was found on official MC-Bauchemie channels at the time of writing — confirm current specs and packaging with Space Arc before ordering
• It is a post-hardening surface cleaner only — not a curing compound, sealer, waterproofing coating or concrete admixture
• Classified Aquatic Chronic 3 (H412) — spent solution and rinse water need proper containment and cannot be discharged directly into drains or water bodies
• Performance depends on soak time and how long the residue has cured; thick, aged laitance may need a repeat application or light mechanical agitation

Selection & best practice

Specifications

Industry use cases

How we position MC-Bauchemie Donnitil 3-X

Donnitil 3-X sits in MC-Bauchemie’s concrete-cosmetics care-and-cleaning line alongside sister products such as Donnitil BGR 81, Donnitil Oil Ex and Donnitil Rust Ex — reach for those where the residue is release-agent film or rust/iron staining rather than cement laitance, since each is formulated for a different stain chemistry. It is not a substitute for MC-Bauchemie’s actual concrete admixtures — plasticisers and retarders such as the Centrament range — which Space Arc also stocks for dosing into fresh concrete; Donnitil 3-X only ever acts on surfaces after the pour has cured. For teams comparing brands, Fosroc’s India catalogue does not carry a direct like-for-like sulfamic-acid facade and equipment cleaner, so most specifiers either stay with a documented, SDS-backed product like Donnitil 3-X or default to generic phosphoric/muriatic-acid masonry cleaners — the latter usually cheaper but with less predictable etching risk and no manufacturer technical backing. Space Arc supplies Donnitil 3-X with the same site-safety and dosage guidance it provides across the rest of the MC-Bauchemie range.

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