Lithofin Rust-EX
Art. 038-21-B
Rust rings under balcony chairs, orange streaks on a kitchen worktop, and iron-rich water spots on porcelain tiles all ruin an otherwise perfect finish. One ready-to-use application of Lithofin Rust-EX eliminates the oxidation before it sets permanently.
What Rust-EX Does
Rust-EX is an acidic cleaner for natural stone, ceramic, and porcelain. At pH 1.5 it converts insoluble ferric oxide into water-soluble ferrous salts. A built-in indicator turns the liquid violet within 2 minutes, confirming the reaction. Wetting agents carry the solution 2-3 mm into porous stone, so the rust lifts out without heavy scrubbing.
When to Use
- Polished marble vanity with a metal perfume-tray ring - apply undiluted.
- Granite patio showing iron spots from lawn furniture - apply undiluted.
- Bathroom porcelain tiles stained by iron-bearing well water - apply undiluted.
- Sandstone facade with old steel anchor marks - pre-wet, then apply undiluted.
- Any surface listed on rust-stain guide - spot treat undiluted.
How to Apply
- Mask adjacent acid-sensitive areas and pre-wet very porous stone. Using a brush or dropper, place Rust-EX directly on the rust until it is fully covered.
- Wait 5-15 min; the liquid turns deep violet. Agitate lightly with a nylon brush if the stain is heavy.
- Rinse twice with plenty of clean water, then neutralise residues with a mild alkaline cleaner if required.
Typical coverage: 50 ml removes a 5 cm diameter rust ring; actual use varies. Surface can be resealed after 2 h drying.
Surface Compatibility
Excellent results on granite, slate, basalt, ceramic, porcelain, and clinker because these acid-resistant materials (Mohs 5-7) tolerate the low pH without etching. Good performance on sandstone, concrete, terracotta, cotto, and glass-mosaic when pre-wetted to slow acid penetration. Do not use on large areas of polished marble; restrict to spots and rinse immediately.
Choosing the Right Product
For ongoing stain protection after rust removal, use MN Stain-Stop. For grease, wax, or general soiling before sealing, clean with MN Power-Clean.
Pro Tips
- Always neutralise with an alkaline cleaner to stop residual acid from re-activating rust - prevents shadowing.
- On very porous stone, repeat a short 5 min application instead of one long dwell to avoid edge darkening.
- Seal cleaned areas within 24 h to block moisture that can carry new iron particles back into the pore structure.
Product Details
Application
- Standard
- Ready to use — do not dilute
Compatibility & Safety
| Surface | Rating | Notes |
|---|---|---|
| Marble | Caution | Contains acid — short contact time, test first |
| Granite | Excellent | Safe and effective on granite |
| Limestone | Caution | Short contact time — test first |
| Sandstone | Good | Effective — pre-wet first |
| Slate | Excellent | Safe on slate |
| Bluestone | Caution | Calcareous — short contact time |
| Basalt | Excellent | Safe on basalt |
| Porcelain | Excellent | Safe and effective |
| Ceramic | Excellent | Safe and effective |
| Glass mosaic | Good | Works on glass |
| Concrete | Good | Effective — pre-wet first |
| Quartz composite | Caution | Test first |
| Terrazzo | Caution | Calcareous — short contact time |
| Terracotta | Good | Pre-wet first |
| Cotto | Good | Pre-wet first |
| Clinker | Excellent | Effective on clinker |
Dosage Calculator
Apply directly to rust stains
Frequently asked questions
Can Rust-EX be used on polished marble?
Yes, but only as a spot treatment. Keep dwell time under 5 min and rinse twice to prevent etching.
How long should Rust-EX stay on granite?
Allow 5–15 min. The colour change to violet shows the reaction is finished; rinse immediately after.
Does Rust-EX alter the appearance of slate?
No. Slate is acid-resistant (Mohs 4); testing shows no colour change after a 15 min dwell.
How much Rust-EX is needed for a 2 cm rust ring?
Approx. 10 ml covers a 2 cm diameter stain, assuming the surface is pre-wetted and level.
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