Clean mixed coins

Question

I have acquired 2kg of assorted coins from various countries. These are to spice up board games by using real metal coins, using material to indicate denomination rather than numbers on the coin eg copper = 1 groat, silver = 5 groats, gold = 10 groats.

I know the advice for valuable coins is never to clean them but these don't have any collectable value. Almost all of them are very dirty and I'd like to get them to a condition where they are pleasant to handle, not necessarily gleaming (but that would be nice). I'm prepared to separate the copper, silver and gold coloured coins (being from different countries, the exact alloy will vary), but I don't want to have to scrub them individually.

I'm also somewhat wary of using acids as this cleans very effectively but leaves the metal dull at least with copper.

Answer 1

If you really want to avoid brushing the coins the easiest method is pour them in a container with coke, let them simmer in it for around 20 min or after you see the dirt and whatever else the coins might have comes off. Afterwards just rinse them in water to avoid stickiness.

Note: I don't know how beneficial or harmful would putting them all together could be for the coins. I would separate them by main materials just to be on the safe side.

Answer 2

You can use tamarind and lemon to scrub the coins and then wash them with water finally.

1. Just soak some tamarind in water for some time and then scrub the coins.
2. Cut a lemon into two halves and then use a half to scrub the coins
3. Finally wash with water.

My mom uses this technique to clean the bronze and copper vessels and trust me they give a fresh and new look after the entire process

Answer 3

Cola!

The joke about it cleaning a 2 pence coin has never been so true, leave them overnight or even longer in some cola, stirring occasionally and they'll come up lovely. Obviously rinse thoroughly to get rid of the cola after so they aren't sticky.

Answer 4

I had this problem some time ago and tested several suggestions. The best process is a two-step one.

First remove the gunge by placing the coins in warm water in an ultrasonic cleaner like this one.

Then soak the coins in a vinegar & salt solution. Overnight at least. Look every few hours & remove if possible.

This resulted in sparkling coins with no degradation of sharpness.

Answer 5

Most coin collectors will use brown sauce to clean coins that are not of the highest value.

Indeed, in my teens I had a Saturday morning job in an antique shop, where brown sauce was used to clean the brass items.

This has mild acid and mild abrasive properties. A quick rub with a soft cloth dipped in brown sauce will bring up a shine on copper and silver coins.
Putting copper coins in cola will clean them but will also given them a pinkish colour, this destroys their value to a coin collector. Sauce does not discolour the coins.

The brand of sauce is irrelevant.

Answer 6

This is what you need:

• 1 clear cups
• salt
• vinegar (you could also use lemon juice)

What To Do:

• fill the 3rd w/1/2 cup vinegar + 2 teaspoons salt & add 20 coins

We left all the coins in the cup for 5 minutes. Take out the coins from the salt & vinegar cup and placed them on a napkin (without rinsing or drying them).

After an additional 5 minutes (10 minutes total for the experiment), we came back to see our results and rinse the coins with water and dry using the napkin.

Answer 7

Expensive, but you could use a firearms brass tumbler. It is a vibrating machine filled with a media like rouge on corn cob bits. Pour your stuff in, turn on, walk away.