About Fosroc Reebaklens RR

Reebaklens RR is Fosroc’s specialist de-rusting solution for reinforcement steel, and it sits at the very start of almost every concrete repair sequence. When cover concrete spalls and rebar is exposed, that steel is usually pitted with rust and mill scale. Mechanical cleaning by wire brush or grinder gets the loose material off but rarely reaches into pits and crevices, and any rust left behind keeps expanding under the new repair mortar. Reebaklens RR is a combination of acid-based material, corrosion inhibitors and dispersing agents, supplied as a clear green liquid, that chemically loosens and lifts this residual corrosion so the bar can be brought back to a sound, coatable surface.

What makes the product practical on site is the temporary passivation it leaves behind. Once the solution has reacted, a thin white layer forms on the cleaned steel that holds off fresh corrosion for roughly five to seven days, giving the repair crew a realistic window to apply Fosroc’s zinc-rich primer or place the repair micro-concrete. Because it is acid-based, it is not a general-purpose degreaser and it is not compatible with every substrate, so it is specified deliberately for ferrous reinforcement and structural steel rather than used as a broad cleaner. Handled with the right precautions, it turns rusted, questionable reinforcement into a properly prepared surface that a durable repair can actually bond to.

The technical insight

Rust is porous, hydrated iron oxide, and it is the reason so many concrete repairs fail early: fresh mortar bonds to the loose oxide layer instead of to sound steel, and the corrosion cell underneath keeps growing. Reebaklens RR works because its acid component reacts with and dissolves that oxide, while the dispersing agents lift the freed particles clear of the pits so a wire brush can finish the job. The corrosion inhibitors in the blend are what set it apart from a raw acid wash: as the reaction completes they leave a thin passivating film, visible as a white layer, that slows the reformation of rust for about a week. That controlled pause is the real value on a live site, where you rarely get to prime cleaned steel the same hour. The trade-off is inherent to the chemistry: being acidic, the solution attacks amphoteric and reactive metals such as zinc, aluminium and galvanised coatings, and it will affect putty, so it must be kept to the ferrous steel it is meant to treat and rinsed or neutralised away from anything vulnerable.

Where it is used

• De-rusting exposed reinforcement bars in spalled or delaminated concrete before patch repair
• Cleaning corroded rebar prior to encasing in repair micro-concrete or polymer-modified mortar
• Preparing structural steel members and connections before application of epoxy protective coatings
• Removing surface rust and mill scale from steel dowels and starter bars on repair projects
• Etching and cleaning steel surfaces so subsequent primers and coatings key in properly
• Restoring corroded reinforcement in facade, balcony and parapet repairs before recoating
• Prep of embedded steel in bridge, water-tank and industrial concrete rehabilitation
• Local touch-up cleaning of rust bloom on stored or partially fabricated reinforcement

Key advantages

• Reaches rust inside pits and crevices that wire-brushing and grinding cannot fully clean
• Leaves a temporary white passivating film that protects cleaned steel for about 5 to 7 days
• Blend of acid, corrosion inhibitors and dispersing agents rather than a raw acid wash
• Simple brush application needing no specialist plant or heated equipment
• Penetrates oil and grease, helping clean contaminated as well as rusted steel
• Improves bond of subsequent primers, coatings and repair mortars to reinforcement
• Compatible in contact with most metals, wood, glass, plastic and rubber when used as directed
• Available in 1, 5 and 20 litre packs to suit both small repairs and larger contracts

Limitations & considerations

• Acid-based, so it must be handled with proper PPE and cannot be used as a general cleaner
• Attacks zinc, aluminium, galvanised steel and putty and must be kept away from them
• Needs a long 16 to 24 hour reaction time, so it is not an instant same-shift solution
• The protective film lasts only about a week, so priming or encasement must follow promptly
• Cleaned steel still requires wire-brushing and dusting before coating, not just chemical action
• Not a substitute for removing heavily section-lost bars that need cutting and replacement

Selection & best practice

Specifications

Industry use cases

How we position Fosroc Reebaklens RR

Reebaklens RR is the surface-preparation step at the front of a Fosroc concrete repair system, not a standalone finish. After de-rusting, specifiers typically move straight to Fosroc Nitozinc Primer as the anti-corrosive coat on the cleaned reinforcement, then reinstate cover with a Fosroc Renderoc repair mortar or micro-concrete. For general form and mould release on the same repair projects, note that Fosroc’s actual release agent range is Reebol, not Reebaklens, so do not confuse the two. Where a contractor prefers a proprietary reinforcement treatment from another brand we stock, comparable rebar priming can be met with Sika’s reinforcement corrosion protection or MC-Bauchemie’s repair primers, but for a matched, warranty-friendly Fosroc repair chain, Reebaklens RR into Nitozinc Primer into Renderoc is the natural specification.

Related Construction Chemicals products

View all Construction Chemicals products →