Old Pennies.Coins.

[migapia]

Hi could anybody be able to tell me if it a good idea to clean old pennies witth brasso, or to clean them at all?  Thank You. Miss Tess

[kopenhagen5 · Accepted solution]

No, don't clean.

They drop in value when cleaned.

Like almost all antiques, left in the natural state with the natural patina is much more desirable for collectors.

[numismatichemist]

As Kopenhagen has said, the general rule is "Don't clean coins". There are some exceptions - for example, if you've dug a coin out of the ground and it's got dirt on it, actual, literal, physical dirt - but for the most part, coins are best left to "look their age". It's against the Second Law of Thermodynamics to ever make an old, worn coin "look like new again", so it's best advised to not try to do so.

Brasso in particular is a nasty thing to apply to a coin. It's an abrasive cleaner, so the end result is something not entirely unlike having applied sandpaper or a belt sander to the coin. Not only does a brassoed coin "look cleaned", but it ends up being covered in fine lines and scratches that degrade the coin's appearance.

[federalbookcollectibles]

Even wiping a coin with a soft cloth leaves tell-tale scratches which devalue a coin. A collector however can always tell when a coin has been cleaned and will usually avoid it like the plague. That said if you just want to pretty up a common coin for your own use or for your own collection you can do whatever you like. If you plan to sell a cleaned coin always be up front and say it has been cleaned. Trying to hide the fact is impossible once a coin is examined under magnification.

Brasso - Tarn-off - steel wool - sandpaper might make it shiny but will quickly wear away any finer detail of a coin. I've been a metal detectorist for many years having done numerous tours in England and Europe and found many thousands of coins in Australia and overseas. For Aussie currently circulating coins you want to clean to spend in parking meters, a small rock tumber does the trick. For crusty pre-decimal dirt covered coins soaking in distilled water (often for weeks) you can slowly clean away the grime with a very soft brush. For heavily encrustated coins soaking in Olive Oil (often for months) and gently cleaning now and then can bring up the detail. For black silver coins shove it in a lemon for 10-20 minutes then gentle cleaning up with soap and warm water. Repeat if neccessary. These methods are gentler on the coin design than abrasives  (aside from using a rock tumber that is) - but will always be obvious.

Of all the ancient Roman and medieval coins and artifacts I've found none have been cleaned other than to get the surface dirt off to bring them back through quarantine. You can't put back on 1800 years of patina (not until 3815AD leastways)

[migapia]

kopenhagen5, Hi I thank you so much for your response, however I have had a go at cleaning some of the pennies !!what can I do now!!

  Cheers and thank you again

[migapia]

Thank u very much for the great info . much appreciated.

[migapia]

Hi thank you for your reply. But I think I have done a terrible thing, "I have attempted to clean some of them" 

     Cheers  and thank you.

[kopenhagen5]

federal gives some good advice above.

Unless it was some of the very early ones or 1946, 1925 or 1930, it won't matter too much, you won't have lost a great deal of (value) money.

But as said, don't clean coins. Same goes for most antiques.

[numismatichemist]

One of the reasons why coin cleaning is regarded negatively is that it cannot be undone - if you decide that the coin looked better before you tried to clean it, well, it's too late, the damage is done. You can't "disclean" a coin, not honestly anyway; while there are ways to "artifically tone" a cleaned coin, such methods are considered to be deceptive and dishonest.