Biodegradable rust treatment for concrete, render and natural stone
Product overview
Benz Rust Cleanze is a biodegradable, non-acid rust treatment designed to remove rust staining from relatively delicate surfaces such as concrete, limestone and sandstone, without significantly whitening or etching the surface.
It is particularly effective for rust stains caused by iron sulphate lawn fertilisers and moss killers, as well as rust marks from metal furniture, BBQs, play equipment and other metal contact points on paths, patios, walls and hardstanding.
Suitable surfaces
Benz Rust Cleanze is suitable for use on the following surfaces:- Concrete slabs, paving and hardstanding
- Render
- Limestone
- Sandstone
- Granite
- Other natural stone surfaces such as York stone, slate and flagstone
- Block paving
Benz Rust Cleanze is used to treat rust staining on these surfaces, including staining caused by iron sulphate fertilisers, moss killers, or rust transfer from nearby metal objects.
It is particularly well suited to situations where acid-based rust removers would be too aggressive and could risk damaging or discolouring the substrate.
Key benefits
- Non-acid formulation – removes rust staining without aggressive acid attack
- Safe for delicate surfaces – suitable for concrete, render and natural stone
- Biodegradable – more considerate around gardens and outdoor areas
- Visible reaction – turns purple on contact with rust, showing the product is working
- Effective on iron sulphate staining – commonly caused by lawn fertilisers and moss killers
How it works
Benz Rust Cleanze works by reacting directly with rust and iron contamination on the surface. When applied to rust staining, the product produces a purple colouration, which indicates that an active chemical reaction is taking place.
This reaction breaks down rust deposits and iron-based staining, allowing them to be loosened from the surface and rinsed away without the need for aggressive acids or abrasive cleaning methods.
Because Benz Rust Cleanze is non-acid, it is far less likely to etch, burn or excessively whiten delicate mineral surfaces such as concrete, render and natural stone. This makes it particularly suitable for use on surfaces where traditional acid-based rust removers would pose a risk of damage.
If no purple reaction occurs during application, the staining is unlikely to be rust-based. In these cases, an alternative stain removal approach may be required.
How to apply
Benz Rust Cleanze is typically applied neat using a brush. For lighter or more recent staining caused by weak iron sulphate solutions, it can be diluted up to 1:1 with water if required.
Pour a sufficient amount of product into a suitable container, such as a paint tray. Apply evenly to the stained area using a brush, ensuring full coverage.
Allow the product to activate for 2–3 minutes, then lightly brush the surface to work the product into the staining. This brush-and-activation process can be repeated as required, up to a maximum of three applications.
Important:
Do not allow Benz Rust Cleanze to remain on the surface for more than 10 minutes in total.
If the surface will not be damaged by agitation, light brushing using abrasive pads or stainless, brass or plastic wire brushes can help remove heavy or crusted rust deposits.
Coverage rates
Coverage will vary depending on the porosity and condition of the surface being treated. The following figures are provided as a general guide:- Concrete: 1–5 m² per litre
- Limestone and sandstone: 1.5–5 m² per litre
- Granite: 8–15 m² per litre
- Block paving: 4–7 m² per litre
More porous or heavily contaminated surfaces will require higher product usage, while smoother or lightly stained surfaces will allow greater coverage.
Safety and responsible use
Always carry out a small test patch in an inconspicuous area before full application.
Avoid allowing Benz Rust Cleanze to dry on the surface. Keep the area damp during treatment and rinse thoroughly once the reaction is complete.
Wear appropriate gloves and eye protection during application, and avoid unnecessary contact with skin or eyes. Clear any spills immediately.
Some light discolouration or whitening may occur on certain coloured concrete or render. This is surface-dependent and reinforces the importance of testing before use.
Dispose of rinse water responsibly and avoid directing run-off into sensitive areas where possible.
Container sizes and supply
Benz Rust Cleanze is supplied in 1 litre containers.
Documentation and downloads
Product documentation, including the Product Data Sheet (PDS), is available to download below for reference before use.