Oil Grease - Expert Removal & Treatment Guide
Oil Grease - Expert Removal & Treatment Guide
What is Oil Grease?
Oil and grease stains are among the most common and stubborn problems on natural stone, particularly in kitchens and dining areas. Oils penetrate into the pore structure of the stone and darken the affected area. Unlike surface stains, oil stains are absorbed into the stone and cannot be removed by surface cleaning alone.
The depth of penetration depends on the stone's porosity and how long the oil has been in contact. Fresh oil stains on granite may only penetrate 1-2mm, while the same stain on porous sandstone or limestone can penetrate several centimetres within hours.
Effective removal requires a poultice method - a paste that draws the oil out of the stone through capillary action. This is a slow process (2-24 hours) but highly effective when done correctly. Prevention through proper sealing is always the best strategy.
How to Identify It
Oil stains appear as darkened areas on the stone. The darkened area often has an irregular, spreading edge pattern (following the stone's pore structure). To confirm: place a drop of water on the stained area and on an unstained area - if the stained area is darker when both are wet, it is an oil stain. Oil stains are NOT raised above the surface (that would be a coating, not a stain).
Common Causes
- Cooking oil splashes and spills
- Food grease (butter, olive oil, salad dressing)
- Cosmetics and body oils
- Motor oil or machinery lubricants (garage floors)
- Furniture polish or wood oil transfer
- Sunscreen and hand cream contact
Prevention
- Seal stone surfaces with an impregnating sealer (Stain-Stop)
- Clean oil spills immediately - speed is critical
- Use trivets and cutting boards in the kitchen
- Apply coasters under oily bottles
- Re-seal kitchen countertops annually
Treatment by Surface Type
Natural Stone
Risk level: High
Apply Lithofin OIL-EX as a thick paste over the stain, extending 2cm beyond edges. Cover with cling film. Leave 2-12 hours. Remove paste, clean with MN Wash & Clean. Repeat for deep stains.
- Porous stones (sandstone, limestone) absorb oil deeply
- Polished surfaces show stains more visibly
- Multiple poultice applications may be needed for old stains
Ceramics
Risk level: Low
For glazed tiles: Lithofin KF Intensive Cleaner is usually sufficient. For unglazed porcelain with absorbed oil: use Lithofin OIL-EX poultice method as for natural stone.
- Glazed tiles rarely absorb oil
- Unglazed porcelain can absorb oil in textured areas
Artificial Stone
Risk level: Medium
For concrete: Lithofin OIL-EX poultice method, leave 12-24 hours. For quartz composite: Lithofin MN Power-Clean usually sufficient. For terrazzo: OIL-EX poultice as for marble.
- Concrete is porous and absorbs oil readily
- Quartz composite is less porous but textured surfaces can trap oil
Cotto Terracotta
Risk level: High
Apply Lithofin OIL-EX generously. Cover with cling film. Leave 12-24 hours. Remove, clean with Lithofin KF Intensive Cleaner. Repeat if needed. Seal surface after treatment.
- Unsealed cotto is extremely porous - oil penetrates deeply
- May require 2-3 poultice applications
- Consider sealing after successful removal
When to Call a Professional
If the oil stain has been present for months and has spread over a large area, or if the stone is an expensive polished marble where the stain has penetrated deeply, a professional stone restorer may need to combine poultice treatment with re-polishing.
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