Hey guys, any tips on solving the color difference that caused by oxidation of copper coins?
I used to let the audience check a normal copper coin then switch it to gimmicked copper coin (such as Sun/Moon, C/S) when those gimmicks are required in my routines.

However, due to oxidation and different time of holding those coins during practice, the color of gimmicked copper coin and ungimmicked coin just goes differently after a while. This makes it obvious for my switch.

I used to buy some copper coins that match the color of my gimmicks before my performance. But after a while, the color of the coins goes different again. It seems unwise to buy coppers coins over and over again in the long run……

You have two real options:

1) Clean your coins often. There are pastes/liquids/gentle substances you can use to brighten your coins to look like new. If you keep doing this regularly, your coins will always look the same -- new!

2) Use a chemical to darken your coins to create a non-naturally formed patina. If done properly, it should significantly reduce the further reaction of the copper, and so they won't continue to change further, and then they'll match forever. However, it's sometime can be hard to get two coins to match when darkening them, so I suggest either going for very dark, or using some kind of product that gives a particular tint.

I guess there's also #3 - make sure you handle both coins equally, rather than holding them for different amounts of time in your routine and practice. But that one can be tricky to manage.

For copper coins that aren't too far gone with age, many have a substance in their refrigerator which can clean them - ketchup. Try it with one that isn't critical to your work and you will see!

Get the coins to the same color, then coat with clear nail polish.
This will change the feel of the coin; so make sure you are "ok" with this first.

John

I don't use gaffs often, but I have a bunch of similar coins...when I need to match, just get the one that matches the best.its really hard to try to change the patina of one coin to match another, and you might ruin your gaff.

The easiest solution is exactly what Doc R. said: have a bunch of similar coins on hand to choose from. Artificially changing patina's is tricky to say the least, but it can be easily avoided by picking up extra coins. Also, as mentioned above by tonsofquestions, make the effort to evenly handle your coins AND gaffs.