The most effective method for preserving copper coins involves gentle cleaning and proper storage to prevent further corrosion.
Here's a detailed breakdown of a suggested preservation process, based on the reference information:
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Gentle Cleaning:
- Washing: Carefully wash the coin in running water.
- Detergent: Use a neutral detergent like Detertec 7 (manufactured by Vetec). The aim is to remove dirt and surface contaminants without damaging the coin's patina.
- Brush: Employ a soft, natural bristle brush to gently scrub the coin. Avoid abrasive materials that can scratch the surface.
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Rinsing:
- Thoroughly rinse the coin under running water to remove all traces of the detergent. Residue can cause long-term damage.
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Drying:
- Initial Drying: Gently pat the coin dry with a clean cotton flannel cloth. Avoid rubbing, as this can scratch the surface.
- Acetone Immersion: Immerse the coin in pure acetone. Acetone helps remove any remaining water and oils, preventing further oxidation. Periodically change the acetone to ensure its purity.
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Storage:
- After the acetone bath, allow the coin to air dry completely.
- Store the coin in a dry, stable environment.
- Use inert, archival-quality coin holders or sleeves designed for long-term storage to prevent contact with harmful materials. Avoid PVC-based holders as they can damage coins.
Important Considerations:
- Patina: Many collectors value the natural patina that forms on copper coins over time. This process aims to preserve the coin while removing loose dirt, not to remove the patina completely.
- Professional Conservation: For extremely valuable or fragile coins, consider consulting a professional coin conservator. They have the expertise and specialized equipment to preserve coins safely and effectively.
- Handling: Always handle coins with clean, dry hands or wear cotton gloves to prevent the transfer of oils and dirt.
- Prevention is Key: The best way to preserve copper coins is to prevent damage in the first place by storing them properly from the beginning.
This process aims to clean the coin and protect it from further environmental damage, thus preserving it for longer.
