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HMK R777 Rust Remover for Granite & Hard Stone
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At a Glance
Quick Decision Guide
Container Size
1 Liter
Coverage
60-80 sq ft
Stone Compatibility
Acid-Tolerant Natural Stone
Removes
Rust Spots & Stains
Future Protection
Helps Reduce New Rust Formation
Application
Ready to Use
Use Location
Interior & Exterior
Professional Use
Yes
Why Choose This Product
Key Benefits
Targeted Rust Removal
Removes rust spots and stains from compatible dense natural stone
Hard Stone Compatibility
Designed for acid-tolerant granite, quartzite, and similar materials
Rust-Inhibiting Additives
Helps reduce the development of new rust after treatment
Ready-to-Use Formula
Requires no measuring, mixing, or dilution before application
Interior & Exterior Use
Treats compatible hard stone surfaces indoors and outdoors
Professional Performance
Provides specialized chemical action for demanding rust contamination
Product Information
Product Details
Specifications
Brand
HMK®
Part Number
R777-1
Product Type
Rust Remover for Hard Stone
Container Size
1 Liter
Coverage
60-80 sq ft
Formula
Ready to Use
Application Type
Surface Treatment
Compatible Materials
Granite, Quartzite & Other Acid-Tolerant Dense Stone
Removes
Rust Spots & Rust Stains
Rust Inhibitors
Helps Reduce New Rust Formation
Application Area
Interior & Exterior
Professional Use
Yes
Surface Preparation
Apply to Dry Surface Only
Direct Sunlight
Do Not Apply in Direct Sunlight
Not Compatible With
Marble, Limestone, Agglomerates, Concrete Products, Plastics & Certain Metal Surfaces
Important Note
Product may temporarily darken stone if allowed to dry on the surface
About This Product
Rust Remover for Granite and Hard Stone
HMK® R777 Rust Remover is a ready-to-use acid-based treatment formulated to remove rust spots and stains from dense, acid-tolerant natural stone. Designed for granite, quartzite, and similar hard stone, it provides specialized cleaning power when rust discoloration affects the appearance of the surface.
Specialized Stone Cleaner for Rust Stains
This rust stain remover chemically targets rust contamination rather than routine dirt or general surface buildup. Suitable for interior and exterior stone, HMK R777 helps restore a cleaner and more consistent appearance across compatible hard stone installations.
Rust Removal with Inhibiting Additives
In addition to removing existing rust stains, HMK R777 contains special additives that help reduce the development of new rust after treatment. This combined cleaning and inhibiting action provides added value for hard stone surfaces affected by recurring rust discoloration.
Common Questions
Frequently Asked Questions
What surfaces can HMK R777 Rust Remover be used on?
HMK® R777 is intended only for acid-tolerant dense natural stone, including granite, quartzite, and similar hard stone surfaces. It is suitable for compatible interior and exterior installations, but the material should always be tested in an inconspicuous area to confirm acid tolerance, appearance, and performance.
What types of stains does HMK R777 remove?
HMK R777 specifically removes visible rust spots and broader rust staining from compatible dense stone surfaces. Its specialized acid-based formula is intended for rust contamination rather than routine dirt, grease, or general maintenance cleaning.
Does HMK R777 help prevent rust from returning?
Yes. HMK R777 contains special additives that help reduce the development of rust after treatment. This rust-inhibiting feature complements the removal of existing stains, giving professionals a treatment that addresses visible contamination while also helping limit new rust from developing.
Can HMK R777 be used on marble or limestone?
No. R777 can damage acid-sensitive and soft stones such as polished or honed marble, limestone, and agglomerates, including their finished surfaces. It should also be kept away from concrete products, plastics, and certain metals. HMK R179 is intended for rust removal on compatible soft stone.
How should HMK R777 be applied?
Do not wet the stone before treatment. Apply R777 undiluted across the entire surface, keep it from drying, cover the treated area with plastic, and allow approximately 12 hours of contact time. Remove the product, clean with diluted HMK R155 Intensive Cleaner, and rinse thoroughly with clean water.
Can HMK R777 darken the treated stone?
Allowing HMK R777 to dry on the stone can temporarily darken the treated surface, although HMK notes that the effect may reverse over time. Keeping the area wet throughout the treatment period and following the prescribed cleanup process helps reduce the risk of this unwanted appearance change.
How much area does HMK R777 cover?
One liter of HMK R777 covers approximately 60 to 80 square feet, while five liters covers approximately 300 to 400 square feet. Actual coverage depends on the stone, severity of rust staining, application method, and whether heavy contamination requires an additional coat or repeated treatment.
Is HMK R777 intended for professional use?
Yes. HMK R777 is designated for professional use only and contains corrosive phosphoric acid. Apply it between 50°F and 80°F, away from direct sunlight, while wearing suitable protective clothing and protecting adjacent surfaces. Turn off underfloor heating and allow the stone to cool before treatment.