Why Cleaning Coins is Almost Always a Bad Idea
At PennyVerse.info, we constantly get asked about cleaning coins. While it might seem like a good way to make old coins look new, professional collectors and numismatists overwhelmingly agree: cleaning coins destroys their value. Here’s what every collector needs to know.
The Harsh Reality of Cleaned Coins
1. Professional Grading Services Penalize Cleaning
- PCGS and NGC designate cleaned coins as “Details – Cleaned”
- This designation typically reduces value by 50-90%
- Even skillful cleaning can be detected under magnification
2. How Cleaning Damages Coins
- Removes original surface and luster
- Creates unnatural hairlines and scratches
- Accelerates future toning in uneven patterns
- Destroys mint-caused patina that collectors value
When Cleaning Might Be Acceptable (Rare Exceptions)
1. For Bullion Coins Intended Only for Metal Value
- Silver/gold coins being sold for melt value
- When appearance doesn’t affect worth
2. For Display Purposes Only
- Coins with no collector value
- When you never intend to sell
3. Professional Conservation (Not DIY Cleaning)
- Performed by NGC/PCGS conservation services
- Uses specialized techniques to stabilize surfaces
- Costs 50−50−300 per coin
Common Cleaning Methods to Avoid
| Method | Why It’s Bad | Typical Damage |
|---|---|---|
| Baking Soda Paste | Abrasive scratching | Cloudy surfaces |
| Vinegar Soak | Chemical etching | Pitted surfaces |
| Silver Polish | Removes metal | Artificial shine |
| Toothbrush Scrubbing | Microscopic scratches | Hairline marks |
| Ultrasonic Cleaners | Vibration damage | Altered surfaces |
Proper Coin Care Alternatives to Cleaning
1. For Dust/Dirt
- Use compressed air (no contact)
- Soft artist’s brush (sable hair)
- Distilled water rinse (no rubbing)
2. For PVC Residue
- 100% acetone soak (no rubbing)
- 5-10 seconds only
- Air dry completely
3. For Storage
- Archival-quality holders (no PVC)
- Anti-tarnish strips in storage
- Climate-controlled environment
How to Identify Previously Cleaned Coins
Look for these telltale signs:
- Uniform hairlines in one direction
- Dull, lifeless surfaces
- Overly bright appearance on old coins
- Rim darkening where cleaner pooled
- Uneven wear patterns
What To Do With Already-Cleaned Coins
- Disclose fully when selling
- Price appropriately (50% of uncleaned value)
- Consider them “placeholder” coins for sets
- Use for educational purposes
Professional Conservation Services
For truly valuable coins that need attention:
- NGC Conservation: 35−35−250 per coin
- PCGS Restoration: 85−85−300 per coin
- ANACS Stabilization: 50−50−200 per coin
Join Our Coin Preservation Community
🔍 At PennyVerse.info you’ll learn:
- Proper long-term storage techniques
- How to handle coins without damage
- Spotting environmental threats
- Creating ideal display conditions
Have a question about a specific coin? Our experts can advise whether professional conservation might be appropriate – contact us first before attempting any cleaning!
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