Quick answer: Clean metal detecting finds as little as possible. Photograph and record an object first, remove only loose soil with gentle handling, and avoid acids, polish, wire brushes and aggressive scrubbing. If a find may be old, fragile, unusual or Treasure, leave it alone and ask your local Finds Liaison Officer for advice.
Finds care for beginners
How To Clean Metal Detecting Finds Without Ruining Them
A sensible beginner guide to cleaning coins, artefacts and metal detecting finds, including when to leave them alone, what not to use, and how to store finds properly.
Important before we start:
This guide is general beginner advice, not professional conservation advice. If you find something that may be Treasure, archaeologically important, fragile, unusual, valuable, or you simply are not sure what it is, do not clean it. Photograph it, record the find spot, keep it safe and contact your local Finds Liaison Officer.
So this guide is not about making every find look shiny. It is about doing the least harm, keeping useful information, and knowing when to leave well alone.
The quick answer
Most metal detecting finds should be cleaned as little as possible. Start by photographing the find, recording where it came from, gently removing loose soil, and identifying what it might be. Avoid acids, harsh chemicals, wire brushes, polishing wheels and aggressive scrubbing, especially on old coins or artefacts.
The golden rule:
Identify first, clean second. If in doubt, do not clean it yet.
Should you clean metal detecting finds at all?
Sometimes, yes. But not always.
There is a big difference between gently removing loose mud from a modern 2p coin and attacking a 700-year-old hammered coin with a toothbrush because you are impatient.
Some finds are fine with a light clean. Some should only be dry brushed. Some should be left exactly as found until someone more knowledgeable has seen them. Some are not worth cleaning at all because they are modern rubbish, scrap or spendable coins.
The problem for beginners is that you do not always know what you have found at first glance. A muddy disc might be a modern coin, a worn Georgian copper, a Roman grot, a token, a trade weight or a completely uninteresting washer trying to get your hopes up.
Before cleaning, ask yourself:
- Do I know what this object is?
- Could it be old or historically interesting?
- Could it be Treasure or part of a larger find?
- Is it fragile, cracked, flaking or powdery?
- Does it have detail, decoration, writing or a surface I could damage?
- Have I photographed it before cleaning?
- Have I recorded where it was found?
If you cannot confidently answer those questions, pause. The find is not going anywhere. Your impatience is the dangerous bit.
What to do with finds before cleaning
The best cleaning starts before you clean anything.
A find without context loses a lot of its value. I do not just mean money. I mean historical value. Where it came from, how deep it was, what field it was in, what else was nearby, and the condition it came out in all matter.
1. Photograph it
Take a photo before cleaning, ideally both sides, with something for scale if possible.
2. Record the location
Note the field, permission, date and rough find spot. A grid reference is even better.
3. Keep it separate
Do not throw delicate finds in with scrap, nails and jagged bits of iron.
4. Let it dry slowly
Do not put finds on radiators, in ovens or under heat guns. Slow and sensible wins.
Beginner mistake:
Getting home, tipping everything onto the table, forgetting which field things came from, then cleaning before taking photos. I know excitement takes over, but get into the habit of recording first.
If it might be Treasure, do not clean it
This is the serious bit, so I will be blunt.
If you find something that might be Treasure, or something that looks unusual, old, valuable, part of a hoard, or historically important, stop messing with it.
Do not polish it. Do not soak it. Do not scrub it. Do not post exact find spots all over Facebook. Do not try to make it look pretty before asking for advice.
What to do instead:
- Stop digging if there may be associated objects.
- Record the exact location as accurately as you can.
- Take photos in situ if safe and sensible.
- Tell the landowner.
- Keep the object safe and separate.
- Contact your local Finds Liaison Officer.
- Follow the proper Treasure reporting process if needed.
Loose soil is one thing. Cleaning an object before it has been assessed is another. If in doubt, leave it alone.
Cleaning finds at a glance
This table is not a replacement for expert advice, but it gives you a sensible beginner starting point.
| Find type | Beginner approach | Avoid | When to ask for advice |
|---|---|---|---|
| Modern coins | Warm water and gentle rubbing is usually fine. | Harsh chemicals if you intend to keep them. | Usually not needed unless it is unusual. |
| Old copper coins | Dry brush gently, identify first, consider leaving patina. | Lemon juice, vinegar, wire brushes, polish. | If it may be Roman, medieval, rare or fragile. |
| Silver coins | Rinse only if safe, pat dry, avoid polishing. | Silver dips, abrasive cloths, polishing compounds. | If old, hammered, fragile or possibly Treasure. |
| Gold | Usually just gentle water if needed. | Chemicals, polish, aggressive rubbing. | If old, marked, decorated or potentially Treasure. |
| Lead, pewter and tin | Handle carefully, dry brush lightly if needed. | Polishing, acids, heavy scrubbing. | If it has marks, decoration, shape or age. |
| Iron | Keep dry, separate and stable. Most iron is scrap. | Soaking important iron, forcing off corrosion. | If it may be an artefact, weapon, tool or unusual object. |
| Buttons, buckles and artefacts | Dry brush gently, do not remove detail or surface. | Stripping patina, polishing, chemical dips. | If decorated, old, unusual or hard to identify. |
A sensible finds cleaning kit
You do not need a mad scientist cleaning bench to look after your finds.
In fact, the more dramatic your cleaning kit looks, the more likely you are to do something silly with it. Most beginners need a simple setup based around gentle handling, organisation and patience.
Soft brushes
A soft toothbrush, artist brush or makeup brush is useful for loose dry soil.
Distilled water
Useful for some gentle rinsing, but do not assume every find should be soaked.
Cotton buds
Handy for very gentle work around details, as long as you are not scrubbing like mad.
Paper labels
A boring item, but one of the most important. Label finds before you forget where they came from.
Small bags or boxes
Keep finds separate. Do not let delicate items rub against scrap.
Patience
The most important bit of kit. Sadly, Amazon still does not sell this in bulk.
What not to use on metal detecting finds
This section will save more finds than any secret cleaning trick.
A lot of bad cleaning advice gets passed around because it makes an object look “better” in the short term. The problem is that better often means stripped, scratched, chemically damaged or historically less useful.
Avoid using:
- Vinegar on old coins or artefacts.
- Lemon juice or other acids.
- Brasso, Silvo or metal polish.
- Silver dip on old or historic silver.
- Wire brushes on coins or artefacts.
- Rotary tools or polishing wheels.
- Bleach, oven cleaner or household chemicals.
- Sandpaper, files or scraping blades.
- Electrolysis unless you really know what you are doing.
- Heat, ovens, radiators or hairdryers for drying fragile finds.
Some of these methods have specialist uses in the right hands, on the right object, for the right reason. That does not mean they belong in a beginner cleaning routine.
If a cleaning method sounds like something you would use to strip paint off a gate, maybe do not put a Roman coin in it.
How to clean old coins found metal detecting
Old coins are where beginners get into trouble.
A modern spendable coin is one thing. An old copper, Roman bronze, hammered silver, token or early milled coin is another. The surface of an old coin can be delicate, and the dirt or patina may be part of what is protecting it.
The first step is not cleaning. The first step is working out what sort of coin you might have.
Beginner approach for old coins
- Photograph both sides before cleaning.
- Record where it was found.
- Let loose wet mud dry naturally if needed.
- Use a soft dry brush only if the surface is stable.
- Stop if detail starts lifting, flaking or powdering.
- Do not polish it.
- Ask for identification advice before doing anything stronger.
With old copper coins, there is often a temptation to keep going until you can see more detail. The problem is that the detail might not be under the corrosion. It might be in the patina itself. Remove that, and you may be left with a smooth, sad little disc.
Hammered silver coins can be very thin and fragile. They may look tough because they are silver, but many are cracked, clipped, bent or delicate. Do not rub them with silver cloths. Do not dip them. Do not try to make them shine like jewellery.
My honest advice:
If the coin is old enough that you would be gutted to ruin it, do not experiment on it.
Cleaning modern coins
Modern coins are usually much less stressful. If you have found a modern pound coin, 20p or 2p that is going in a jar, you do not need museum-level care.
Warm water and gentle rubbing is usually enough. If it is just a spendable coin, you are not preserving a national treasure.
That being said, do not let the relaxed approach to modern coins become your default approach for everything. Beginners sometimes get comfortable cleaning modern coins, then use the same energy on an old coin and regret it.
Simple modern coin clean
- Rinse in warm water.
- Rub gently with fingers or a soft cloth.
- Dry with a towel.
- Keep separate from older finds.
If it turns out not to be modern, stop and reassess before you keep cleaning.
Cleaning copper, bronze and brass finds
Copper alloy finds include all sorts of interesting things: old coins, buckles, buttons, harness fittings, brooches, tokens, thimbles and mystery objects that make you lose half an evening on Google.
They can also be very easy to ruin.
The green, brown or dark surface on copper alloy finds is often patina. That patina can be attractive, protective and historically important. It is not always “dirt” that needs removing.
Safer beginner approach
- Let wet soil dry naturally.
- Use a soft dry brush for loose dirt.
- Use a wooden cocktail stick very carefully only on loose soil, not the surface itself.
- Stop if the surface starts flaking or powdering.
- Do not chase a shiny finish.
Avoid vinegar, lemon juice, metal polish and heavy scrubbing. They may reveal detail quickly, but they can also strip surfaces, change colour and leave the find looking unnatural.
With copper alloy finds, less is usually more.
Cleaning silver finds
Silver can be deceptive.
Sometimes silver comes out of the ground looking lovely. Sometimes it is black, dull, stained or covered in soil. The temptation is to polish it up until it shines. Try to resist that temptation, especially if the find is old.
Modern silver jewellery and historic silver artefacts should not be treated the same way. A modern silver ring found on the beach is not the same as a hammered silver coin or an old decorated artefact.
For older silver finds:
- Photograph before cleaning.
- Record the find spot (see our guide on researching land and recording finds).
- Gently remove loose soil only.
- Avoid silver dips and polishing cloths.
- Do not bend, flatten or straighten.
- Ask your FLO if it may be Treasure.
Silver dips and foil methods may be common in jewellery cleaning, but that does not make them suitable for historic finds. They can alter the surface and remove information that should have been left alone.
If the find is old silver, treat it as important until someone knowledgeable tells you otherwise.
Cleaning gold finds
Gold is the dream for many detectorists, but it also needs a calm head.
Gold does not usually corrode like iron or copper alloy, so it often comes out of the ground looking surprisingly clean. A gentle rinse may be all it needs, if anything.
If you find a modern gold ring, you may be dealing with lost property rather than an archaeological find. If you find an old gold object, especially something decorated, broken, associated with other finds or potentially over the Treasure threshold, do not treat it like normal jewellery.
Gold rule:
Gentle water only if needed. No chemicals, no polish, no bending, no “let’s see if this mark comes off”. On your head be it.
If it may be old or important, contact your FLO before doing anything else.
Cleaning lead, pewter and tin finds
Lead, pewter and tin can look dull, grey, white, dark or powdery. They often have a soft, aged surface that is very easy to damage.
I once tried to clean a musket ball and completely ruined the aged look. It went from “interesting old find” to “plain ball of lead” in no time at all. Lesson learned.
These materials are often better left alone or very lightly brushed. Do not try to make them shiny. They are not meant to look like they just came from a shop.
Beginner care tips
- Handle carefully.
- Use a soft dry brush only if needed.
- Do not polish.
- Do not scrape white or grey surface layers aggressively.
- Store dry and separate from other finds.
- Ask for advice if there are marks, decoration or unusual shapes.
A lead token, seal, weight or musket ball may look simple, but it can still have useful information. Do not clean the history out of it.
Cleaning iron finds
Most iron you dig will be rubbish. Nails, bolts, farm bits, broken machinery, shrapnel, odd lumps and all the usual hedge fodder we should not actually throw in the hedge.
But occasionally iron finds can be interesting. Tools, weapons, keys, locks, knives, horseshoes, fittings and other objects may deserve more care.
The difficulty with iron is that it can be unstable once removed from the ground. Rust and corrosion can continue, especially if it is stored damp.
For iron finds:
- Separate scrap from anything potentially interesting.
- Keep possibly interesting iron dry.
- Do not soak historic iron unless advised.
- Do not force off corrosion layers.
- Ask for advice if the object may be old or significant.
Wire brushing a modern rusty bolt is one thing. Wire brushing an old iron artefact before anyone has identified it is another.
If it looks like a weapon, tool, lock, key, old fitting or anything unusual, photograph it and ask before you attack it.
Cleaning buttons, buckles and artefacts
Buttons, buckles and small artefacts are some of the most enjoyable finds to research.
They can also be very easy to damage if you clean them like coins.
A button may have a maker’s mark, gilding, decoration or fragile surface. A buckle may have traces of tinning, iron pins, gilding or wear patterns. A small artefact may have detail hidden under soil that you could remove without realising.
Safe beginner approach
- Photograph both sides.
- Let mud dry naturally if wet.
- Use a soft dry brush for loose dirt.
- Do not scrub gilding, decoration or markings.
- Keep mixed-material finds dry and stable.
- Ask for identification before deeper cleaning.
The aim is not to make every artefact sparkle. The aim is to preserve what makes it interesting.
How to store metal detecting finds
Cleaning gets all the attention, but storage is just as important.
A find can survive hundreds or thousands of years in the ground, then start deteriorating after you dig it up because the environment has changed. Moisture, oxygen, poor packaging, heat, handling and being chucked into a box with other finds can all cause problems.
Good storage habits
- Store finds dry.
- Keep delicate finds separate.
- Use small boxes, bags or trays.
- Label finds with date, field and permission.
- Do not store damp finds in sealed bags.
- Keep iron away from better coins and artefacts.
- Avoid direct sunlight, heat and damp sheds.
- Use acid-free materials for anything important.
A biscuit tin full of mixed finds feels charming until a jagged bit of scrap scratches a decent coin or you forget which permission half the items came from.
Organisation may be boring, but future you will be grateful.
Labelling and recording finds
If there is one habit I would force every beginner to build, it is recording finds properly.
It does not have to be complicated. You do not need a museum database on day one. But you should know where each interesting find came from.
Record these details:
- Date found.
- Permission or field name.
- Rough grid reference or GPS location if appropriate.
- Depth, if known.
- Detector used.
- Object description.
- Photos before and after any cleaning.
- Any identification notes.
- Whether it has been shown to the landowner or FLO.
This helps you, the landowner, the FLO and anyone who may look at the find in the future. It also makes your own collection much more interesting.
A coin with a label and story is better than a random coin in a box that you vaguely remember finding “somewhere near that hedge, maybe”.
Common beginner cleaning mistakes
Most cleaning mistakes come from excitement, impatience or copying bad advice.
Cleaning before identifying
The biggest mistake. Work out what it might be before you decide what to do.
Using acids
Vinegar and lemon juice are common bad ideas for old coins and artefacts.
Polishing silver
Old silver is not modern jewellery. Do not polish away its character and surface.
Scrubbing copper
You can remove the very surface that holds the remaining detail.
Mixing good finds with scrap
A decent coin and a rusty nail should not be best mates in the same pouch.
Forgetting find spots
Cleaning is not the only way to ruin information. Poor recording does it too.
When should you contact your FLO before cleaning?
Your local Finds Liaison Officer, part of the Portable Antiquities Scheme, is there to help record and identify finds. They are not someone to be scared of.
If you are new, it is better to ask a silly question than ruin a good find because you were too proud to get advice.
Contact your FLO if:
- The find may be Treasure.
- The object looks very old or unusual.
- You have found multiple objects close together.
- It may be Roman, medieval, Saxon or prehistoric.
- It is fragile, decorated or has writing.
- You think it may be part of a hoard.
- You are not sure what it is and do not want to damage it.
Send clear photos, measurements, weight if possible, and basic find spot information. Do not send the object through the post unless they specifically advise you to.
Summary: how to clean metal detecting finds safely
The safest way to clean metal detecting finds is to do less than you think.
Photograph first. Record the find spot. Identify what you might have. Remove loose soil gently. Avoid harsh chemicals, acids, metal polish and aggressive scrubbing. Keep interesting finds separate from scrap. Store them dry, labelled and protected.
Modern coins can usually cope with simple cleaning. Old coins, artefacts, silver, copper alloy, lead, pewter, iron and anything potentially important need more care.
If a find might be Treasure, or you are unsure what it is, do not clean it. Ask your FLO.
It is better to have a slightly muddy find with its history intact than a shiny ruined one you wish you had left alone.
Next beginner guide
Need help identifying a find?
Before you clean too much, it is worth working out what you have found. Good photos, measurements and the right resources can save a lot of guesswork.
FAQs about cleaning metal detecting finds
Should I clean metal detecting finds as soon as I get home?
Not straight away. Photograph them first, record where they came from, and try to identify what they might be. If a find looks old, fragile or important, leave it alone and ask for advice.
Can I use vinegar to clean old coins?
I would avoid it. Vinegar is acidic and can damage old coins and artefacts, especially copper alloy finds. It may make something look cleaner quickly, but it can also strip surfaces and ruin detail.
Can I polish silver coins found metal detecting?
Do not polish old silver coins. A modern silver ring and a historic silver coin are not the same thing. Polishing can scratch the surface, remove patina and reduce historical or collector value.
What is the safest way to clean an old coin?
The safest beginner approach is to remove only loose dirt, usually with a soft dry brush, and stop if the surface looks unstable. Identify the coin before doing anything more.
Should I soak metal detecting finds in water?
Not automatically. Some modern coins are fine with water, but some archaeological finds can be unstable or fragile. Do not soak unknown, fragile or potentially important finds unless you have good advice.
How should I store metal detecting finds?
Store finds dry, separate and labelled. Keep delicate objects away from scrap, avoid damp sheds and plastic bags full of wet soil, and record the field, date and location details while you still remember them.
What should I do if I find something that might be Treasure?
Do not clean it. Record the exact location, tell the landowner, keep it safe and contact your local Finds Liaison Officer. Possible Treasure must go through the proper reporting process.
Is it better to leave patina on finds?
Usually, yes. Patina can protect the object and form part of its appearance, age and history. Removing it can make the find less attractive, less stable and less useful for identification.
Sources and further reading
These links support the guidance above and provide further reading. Check country-specific rules where noted.
- GOV.UK: Report treasure, wreck material or archaeological finds: The official reporting process, 14-day deadline and country differences.
- First Aid for Finds: Examination and cleaning: Conservation-led guidance warning against non-specialist cleaning of coins, tokens and fragile evidence-bearing finds.
- Canadian Conservation Institute: Care of coins and medals: Government conservation guidance on handling, storage and protective materials.
- Portable Antiquities Scheme database: Official resource for researching and recording archaeological finds.
- PAS Cymru: Official Welsh reporting and recording guidance.
