can you acid date mercs?

Geoman

I know a little about why people would etch or "acid-date" a Buffalo nickel. But does that work on other coins also? Or only on Buffalos? The reason for asking, is could you use that technique on the reverse of AG-3 merc's to see if there is a "D" worn off from a 1916 dated AG-3 Merc? I can pick up an AG-3 merc for a mere $1. Do you think it is possible for a "D" mintmark to be worn off completely so you can not see it with the naked eye?

What is the procedure and technique, along with cost, to acid date a coin?

airplanenut

I dont' think it's possible- it's a different, softer metal... besides, you probably wouldn't find one because at the AG level, they are so weak to begin with and the coin so smooth...

jonesy

You'd have to use nitric acid. Sulfuric acid would blacken it only. Then, it still might not work.
Glenn

Conder101

Nitric acid will also turn it black. that is one of the problems with trying to "acid date" silver coins. Most silver compounds are light sensitive and will turn black upon exposure to light. You might try usin Hydrochloric acid though. Silver Chloride is a white compound and is not light sensitive. As airplanenut says, silver is a softer metal but it should still work. Since it is softer though I would use a more dilute aid solution. It will be a slower process but a stroger solution runs the risk of eating through the layer too quickly, first restoring the date and then removing it again. Using a more dilute solution, applying and rinsing, and doing that repeatedly would probably result in the best chance of bringing out a date.

baccaruda

can someone explain "acid date". i know it's when you put acid on a buffalo nickel to be able to see the date, but why does it work?

Conder101

When the coin is struck the metal of the coin is compressed and work hardened. Because the die has different amounts of relief, the hardness of the metal at any point on the coin varies in direct propotion to the relief of the die at that point. When the acid is applie it attacks the softer areas at a slightly greater rate than the harder areas etching away a little more metal there than elsewhere. This results in a ghostly image recreating the designs present in the die thus allowing you to see what the date was.

baccaruda

cool. was this a common thing to do? i can think of many i've seen that fit that description.

Geoman

It was somewhat common for Buffalo nickels, as the design of that coin produced a date that was raised up, and worn off more easily than other coins. I have never heard it done on other coins.

But with the difference in price between a 1916 and a 1916-D Mercury, I thought about trying it on a bunch of old Merc's that have well worn reverses, to see if any of them reveals a "D" mint mark. Mainly thinking about doing it for the fun of it, and see what I turn up. Also, I have access to a lab at school, with all types of acids, and safety supplies.

baccaruda

hell, i want to try one now.