How to Properly Store and Preserve British West Africa Coins: A Conservationist’s Guide to Toning, PVC Damage, and the Age-Old Question of Cleaning

I’ve seen too many valuable pieces ruined by improper cleaning or storage. Here is how to keep yours safe for the next generation.

As a conservationist who has spent decades examining, grading, and preserving world coinage — including the often-overlooked but historically rich series of British West Africa — I can tell you that the single greatest threat to your collection is not market fluctuations or forgery. It is us. Our well-intentioned but misguided attempts to “improve” a coin, our careless storage choices, and our ignorance of the chemistry of metals destroy more numismatic value every year than any other factor combined.

The recent forum discussion about assembling a British West Africa set — touching on everything from the elusive 1946H Shilling to the rare Edward VIII issues of 1936, the mysterious 1920-G coinage struck by J.R. Gaunt & Sons, and the hoard dates that are common on paper yet virtually nonexistent in high grades — is a perfect springboard for this critical topic. Whether you are debating whether to sell a group of freshly slabbed BWA pieces or committing to building the full series, the decisions you make right now about preservation will determine whether those coins retain their value, beauty, and historical integrity for decades to come.

Let me walk you through the five essential areas every collector must understand: toning, oxidation, PVC damage, proper holders, and the eternal question of whether to clean or not to clean.

Understanding Toning: Beauty, Value, and When It Becomes a Problem

Toning is the natural chemical process by which a coin’s surface reacts with sulfur compounds, moisture, and other elements in its environment. On copper, bronze, and copper-nickel coins — the very metals that dominate the British West Africa series — toning can range from a light, attractive golden hue to vivid rainbow patina to dark, destructive corrosion.

I’ve examined thousands of BWA pieces over the years, and I can tell you that toning on these coins tells a story. The copper-nickel 1/10 Penny, 1/2 Penny, and Penny issues of Edward VIII (1936), for example, are just 20.5 mm, 25.2 mm, and 30.5 mm respectively — small, thin coins that are particularly susceptible to environmental toning because of their high surface-area-to-mass ratio. A lightly toned 1936 Edward VIII Penny with original, undisturbed color is a genuine thing of beauty. A coin that has been stored in a damp basement for forty years and developed thick, dark sulfide layers, on the other hand, has lost both its eye appeal and a significant portion of its value.

The Spectrum of Toning on BWA Coinage

• Original Mint Luster with Light Golden Toning: This is the ideal. The coin retains most of its original cartwheel effect, with a thin, even layer of golden or light amber toning. On silver issues like the BWA shillings, this manifests as a soft, creamy gold. Collectors pay a premium for this look — and rightfully so.
• Rainbow or Multicolored Toning: Often seen on coins stored in older cardboard holders or albums with sulfur-containing materials. While sometimes attractive and even premium-worthy, it can also indicate prolonged exposure to reactive chemicals. Context matters: natural rainbow toning with strong eye appeal can boost collectibility dramatically, while uneven, blotchy coloration will hurt it.
• Dark or Mottled Toning: Usually a sign of poor storage. This type of toning obscures design details, is nearly impossible to reverse without damage, and significantly reduces collector appeal. When I see heavy mottling on a BWA piece, my first question is always: where has this coin been?
• Active Corrosion (Verdigris on Copper/Bronze): Green, powdery spots that are actively eating into the metal. This is an emergency situation requiring immediate isolation of the affected coin. Left unchecked, it will spread to neighboring pieces and can destroy the surface entirely.

What I Recommend

Never attempt to “enhance” toning artificially using chemicals, eggs, or other home remedies. I’ve seen collectors ruin perfectly good coins trying to create rainbow effects. If a coin has attractive, natural toning, leave it alone. The market rewards originality, and any attempt to alter a coin’s surface is considered damage by grading services and serious collectors alike. That natural patina is part of the coin’s provenance — its life story written in chemistry.

Oxidation: The Silent Killer of Copper and Bronze Coins

Oxidation is the broader chemical process that encompasses toning but extends to more destructive reactions. On the copper and bronze denominations that make up the bulk of the British West Africa series — and indeed most pre-decimal Commonwealth coinage — oxidation is the primary long-term threat.

Consider the historical context that forum members have highlighted: much of the silver BWA coinage was melted after 1950 during the transition from 80% to 50% silver content, and again during the decimalization of 1961 and the silver bubble of 1979–1980. The coins that survived did so largely by chance. Many were stored in tropical West African climates — hot, humid, and rich in atmospheric sulfur from industrial and agricultural activity. The oxidation patterns on surviving BWA pieces often reflect decades of exposure to these harsh conditions. It’s a wonder any of them survived in mint condition at all.

The non-silver issues — the copper-nickel pennies and fractions — are even more vulnerable because copper-nickel alloys, while harder than silver, are prone to a particular form of oxidation called chloride attack that can cause pitting and permanent surface damage. Once that pitting sets in, there’s no going back.

How to Minimize Oxidation

1. Control Humidity: Store coins in an environment with relative humidity between 30% and 40%. Above 60% humidity, oxidation accelerates dramatically. Use silica gel packets in your storage area and replace or recharge them regularly. A small digital hygrometer is one of the best investments you can make.
2. Minimize Air Exposure: The less air that circulates around your coins, the slower oxidation proceeds. This is one reason professional grading slabs are so effective — they create a near-sealed environment. For raw coins, individual capsules or airtight flips make a real difference over time.
3. Avoid Reactive Materials: Never store coins in PVC-containing plastics, rubber bands, paper clips, or wooden cabinets that off-gas acids. More on this in the PVC section below — and trust me, it deserves its own section.
4. Wear Cotton Gloves: The oils and salts on human skin are mildly corrosive to copper and bronze. Always handle BWA coins with clean cotton gloves or by the edges only. I know it feels fussy, but after seeing what twenty years of bare-handed handling does to a penny’s luster, I never skip this step.

PVC Damage: The Most Common and Most Preventable Tragedy

If I could collect every coin ever damaged by PVC and display them as a cautionary museum exhibit, I would. PVC (polyvinyl chloride) damage is, in my experience, the single most common form of preventable damage I encounter in collections of world coinage — and British West Africa pieces are no exception.

PVC was once the standard material for coin flips, holders, and albums. The problem is that PVC is chemically unstable. Over time, it breaks down and releases hydrochloric acid and chlorine gas. These compounds react with coin surfaces to create a characteristic green, sticky, slimy residue that I call “PVC slime.” Once this residue bonds to a coin’s surface, it causes permanent etching and pitting that cannot be reversed without abrasive cleaning — which itself causes further damage.

The forum discussion mentions coins being found “over graded in plastic” — and I would wager that at least some of those coins were housed in PVC-based holders at some point, which may have contributed to surface degradation that was not apparent at the time of grading but became visible later. This is one of the most insidious aspects of PVC damage: it’s a slow-motion disaster that can take years to become visible.

How to Identify and Prevent PVC Damage

• The Smell Test: PVC flips and holders have a distinctive “shower curtain” or “new car interior” smell. If your plastic coin holder smells like plastic, it likely contains PVC. Replace it immediately. Your nose knows.
• The Visual Test: Look for greenish or cloudy residue on the coin surface, especially around the edges and in recessed design areas. Early-stage PVC damage appears as a light green or milky film. If you spot this, act fast — the longer the coin stays in contact with PVC, the worse the damage becomes.
• The Flexibility Test: PVC flips tend to be somewhat rigid and become brittle over time. Mylar (polyester) flips, by contrast, are clearer, more flexible, and chemically inert. When in doubt, toss the PVC and buy Mylar. It’s cheap insurance.

Safe Alternatives to PVC Holders

1. Mylar (Polyester) Flips: The gold standard for individual coin storage. Brands like Saflip are widely available and inexpensive. I use these for the majority of my raw collection.
2. Acrylic Holders: Hard acrylic capsules provide excellent protection for individual coins and are completely inert. They’re my go-to for display pieces where I want the coin visible from both sides.
3. Cardboard 2x2s with Mylar Windows: Traditional, archival-safe, and allow for easy labeling and organization. There’s a reason collectors have trusted this format for generations.
4. Professional Grading Slabs (PCGS, NGC, etc.): For valuable pieces like the scarce 1946H Shilling or the Edward VIII issues, third-party grading provides both authentication and a sealed, inert environment. The peace of mind alone is worth the grading fee.

Choosing the Right Holders for Your British West Africa Collection

Building a British West Africa set — whether focusing on the shillings, the Edward VIII copper-nickel issues, or the full denominational range — requires a thoughtful approach to storage that balances protection, accessibility, and cost.

Here is my recommended hierarchy for BWA coin storage, based on value and rarity:

1. Key Dates and Scarce Issues (e.g., 1946H Shilling, 1920-G coinage, 1936 Edward VIII pieces): Professional grading and encapsulation. These coins deserve the highest level of protection and authentication. As one forum member noted, the 1946H Shilling is genuinely difficult to find in nice condition — when you do locate one, protect it accordingly.
2. Semi-Key Dates and Better Grades: Mylar flips in archival-quality albums or boxes. Label each flip with date, denomination, mint mark, and grade. Good record-keeping now saves headaches later.
3. Common Dates in Lower Grades: Cardboard 2x2s with Mylar windows, stored in archival boxes. This is cost-effective for the bulk of the series and still provides solid protection against environmental damage.
4. Reference and Study Pieces: Even your lower-grade coins deserve proper storage. Never use paper envelopes, plastic bags from the grocery store, or — heaven forbid — rubber bands and tape. Every coin in your care should be treated with the same basic respect.

I also want to address a point raised in the forum thread about the David Vice Collection, which was auctioned by Heritage in 2016. Collections of this caliber are typically stored and presented in archival materials from the outset, which is one reason they command premium prices. The provenance of a well-preserved, properly housed collection adds tangible value. If you aspire to build a collection of similar quality, start with proper storage from day one.

To Clean or Not to Clean: The Conservationist’s Definitive Answer

This is the question I am asked more than any other, and my answer is always the same: Do not clean your coins.

I know this is frustrating. I know that when you pull a British West Africa penny out of an old album and it is covered in dark, ugly toning, your instinct is to make it look “nice” again. But I have examined coins that were cleaned with everything from pencil erasers to commercial dip solutions to toothpaste, and the damage is always the same: the original surface has been stripped away, the natural patina has been destroyed, and the coin has been permanently devalued.

Here is what cleaning actually does to a coin:

• It removes original mint luster: Once the microscopic flow lines and frost that constitute mint luster are gone, they cannot be restored. A cleaned coin will always look “flat” or “washed out” to a trained eye. That cartwheel effect that makes a mint-state coin come alive? Gone forever.
• It creates artificial surfaces: Dipping a coin in acid removes toning, but it also removes a thin layer of metal. The resulting surface is unnaturally bright and uniform — a dead giveaway to any experienced grader. I can spot a dipped coin across a crowded bourse floor.
• It causes microscopic scratching: Even the gentlest cleaning methods introduce fine scratches that are invisible to the naked eye but glaringly obvious under magnification. These scratches disrupt the original strike and permanently diminish the coin’s eye appeal.
• It destroys historical evidence: Toning, patina, and even moderate oxidation are part of a coin’s history. A cleaned coin has had its biography partially erased. For a series like British West Africa, where provenance and survival stories matter so much to collectors, that loss of context is itself a form of damage.

The Only Exception: Removing Active Corrosion

The only circumstance under which I would recommend any form of intervention is when a copper or bronze coin shows signs of active verdigris — green, powdery spots that are actively spreading. In this case, the corrosion will eventually destroy the coin entirely if left unchecked. This isn’t about aesthetics; it’s about saving the coin from itself.

If you must address active corrosion, here is the safest approach:

1. Isolate the coin immediately to prevent contamination of other pieces. Put it in a separate Mylar flip and move it away from the rest of your collection.
2. Gently remove loose corrosion with a wooden or plastic toothpick under magnification. Do not use metal tools. Work slowly and carefully — you’re not scrubbing a pot, you’re stabilizing a rare variety that may be one of only a handful known.
3. Stabilize the coin by applying a thin coat of Renaissance Wax or a similar museum-grade microcrystalline wax. This creates a barrier against further oxidation without altering the coin’s appearance. I’ve used this method successfully on numerous copper pieces over the years.
4. Consult a professional conservator for valuable pieces. This is not a DIY situation for key dates. The cost of professional conservation is a fraction of what you’d lose if a rare BWA piece were to deteriorate further.

I want to emphasize: this is a last resort for emergency preservation, not a routine maintenance procedure. Ninety-nine percent of coins should never be touched beyond careful handling with gloved hands.

Special Considerations for the British West Africa Series

The BWA series presents some unique preservation challenges that collectors should be aware of, based on the specific characteristics discussed in the forum thread.

The Edward VIII Issues (1936)

The 1/10 Penny, 1/2 Penny, and Penny of Edward VIII are historically significant as coins of a king who abdicated before most of his coinage entered circulation. These copper-nickel pieces are small and thin — the 1/10 Penny weighs only 1.9 grams — making them particularly susceptible to edge damage and environmental toning. Store these in individual capsules or flips, and handle them with extreme care. Given their rarity and historical importance, any Edward VIII BWA piece in strong grade with original luster deserves professional encapsulation. The collectibility of these issues only increases with time, and preserving them properly now protects that long-term numismatic value.

The 1920-G Coinage

The 1920-G issues, struck by J.R. Gaunt & Sons — a firm whose only production of coins was this very series, with nearly all pieces subsequently melted or destroyed — are among the most historically interesting pieces in the BWA series. If you are fortunate enough to own one, it deserves professional-grade storage and conservation. These coins are irreplaceable artifacts of a fascinating numismatic footnote. The strike quality on surviving examples varies considerably, so preserving whatever detail exists is paramount.

The Elusive 1946H Shilling and Other Scarce Dates

As forum members have noted, certain dates like the 1946H Shilling are genuinely difficult to locate in nice condition. When you do find one — especially if it is overgraded or overpriced — consider whether the coin has been properly stored. A coin that has been in a PVC holder for decades may look acceptable to an untrained eye but may have hidden surface damage that will worsen over time. If you purchase such a coin, immediately transfer it to an archival-quality holder and assess its true condition under good lighting and magnification. Don’t trust the grade on the slab if you suspect the coin’s storage history was problematic.

Hoard Dates and Survival Rates

The forum discussion correctly notes that BWA has several hoard dates, but also that some dates cataloged as “fairly common” are virtually nonexistent in high grades. This is a critical preservation insight: the coins that do survive in high grade are often the ones that were stored properly from the beginning — in dry conditions, away from reactive materials. The common-date coins in low grade that fill dealer trays are the ones that were neglected. This disparity in survival rates is itself a testament to the importance of proper storage. Every well-preserved BWA coin in your collection represents a small victory against entropy.

Practical Action Plan for BWA Collectors

Let me leave you with a concrete, actionable checklist that you can implement today:

1. Audit your current storage: Go through every holder, album, and box in your collection. If anything contains PVC, replace it immediately with Mylar or acrylic alternatives. This single step will do more for your collection’s long-term health than anything else on this list.
2. Assess your environment: Buy a hygrometer for your storage area. If humidity exceeds 50%, invest in a dehumidifier or add silica gel packets. Consistent environmental control is the foundation of good preservation.
3. Never clean a coin: Commit this to memory. Write it on a sticky note and put it on your desk. The only acceptable intervention is stabilization of active corrosion on valuable pieces, and even then, consult a professional. Your future self — and the next owner of that coin — will thank you.
4. Handle with gloves: Keep a box of cotton gloves near your work area. Make it a habit. Bare fingers and copper-nickel alloys are not friends.
5. Grade and slab your best pieces: For key dates, scarce issues, and any coin you consider selling or insuring, professional grading provides both authentication and permanent archival storage. The encapsulated environment is one of the most effective preservation tools available.
6. Document your collection: Photograph each coin in its current state. This creates a baseline for future comparison and is invaluable for insurance purposes. Include a scale reference and note any existing toning, marks, or areas of concern.
7. Educate yourself continuously: As the forum thread demonstrates, the best resources for BWA collectors include specialized reference books, auction catalogs like the Heritage sale of the David Vice Collection, and the collective knowledge of experienced collectors. Seek out these resources and learn from them. The more you understand about the metals, the minting process, and the environmental factors at play, the better equipped you’ll be to protect your collection.

Conclusion: Preserving History for the Next Generation

The British West Africa series is a remarkable chapter in numismatic history — a window into the colonial monetary systems of West Africa, the industrial capabilities of British mints and private firms like J.R. Gaunt & Sons, and the economic transitions of the mid-twentieth century. From the tiny 1.9-gram 1/10 Penny of Edward VIII to the elusive 1946H Shilling, each coin carries a story that deserves to be preserved with care and respect.

As collectors, we are not merely owners of these pieces — we are stewards. The decisions we make about storage, handling, and preservation today will determine whether these coins survive in collectible condition for the next generation of historians, collectors, and enthusiasts. I’ve seen too many valuable pieces ruined by ignorance or carelessness. Don’t let your collection be one of them.

Store smart. Handle gently. Never clean. And above all, respect the history in your hands.

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