Questionable 1967 Quarter Error...

I frankly don't know if it's "dryer" or "drier", but this much I do know - if it has been in there for years, as some have, or weeks, as some have, it'll make a "yuge" difference. Age-related impending deafness is a dangerous thing. I once had a cat that died of it. SPLAT! He never moved as the car approached.

As for differential resistance to failure of 100% Cu vs. 75/25 Cu/Ni, I'm pretty sure that's why they chose the 75/25 Cu/Ni option. It's tough stuff against many corrosives while still retaining strikability. They don't just choose these alloys at random out of a hat, you know.

I've been privy to some "inside discussions" over a new alloy to replace 75/25 in our circulating coins. No, bullionistas, they're NOT bringing silver back, calm down, deep breaths. If they spent even 1/10 the time getting TO 75/25 as they've spent getting OUT of 75/25, they spent beaucoup time on it.

By the way, a "drier" coin is less wet, right?

 

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Yes acetic acid, reacts well with copper (in the presence of oxygen), forms copper acetate which is water soluble. The acetate dissolves away exposing fresh copper to the reaction.

 

Couple of comments...1) a dryer (or drier) coin has the APPEARANCE of a coin caught in a dryer and tumbled till the edge flattens out...doesn't mean than is the way it came about any more than a grease filled die was filled with grease, just a tag we put on things and I think most of them are actually "spooned" (look it up). 2) since I have a background in chemistry, I have some acetic acid at my house (along with some hydrochloric, phosphoric, sulfuric and phosphoric...shhh, don't tell OSHA or EPA) and could do a test, but only if no one quits CT as a result of this.

 

Speaking of tumbling a coin, I once put a shiny new nickel in a rock tumbler for a few days, running of course. With grit in it, of course. All the same stuff you'd do to rocks. It really came out weird. The best way I can describe it is like a Matte Proofy finish with all the details gone from it. Sharp rims? Ummm, no.

 

Well, so far I've been provided with references to articles on etching copper and on corroding copper, neither of which would apply to the OP's quarter. Also an article on phosphoric acid which is mildly corrosive to nickel alloys. Add a statement that carbonic, phosphoric, and sulfuric acids attack copper more than nickel alloys. None of this answers what DID cause the damage to the quarter.

It's also been implied that I have made up nonsense and can't be trusted. That is a valid opinion and I won't challenge it. Think what you want. I will say that in the case of this thread I did not say what did cause the damage to the quarter, only what did not.

I will say that I have a background in which certain ideas are acceptable only when they are backed up with empirical evidence or other unchangeable proof. When I see that someone actually makes a "drier" coin or a duplicate of the OP's quarter, then, and only then will I accept the method of production. Until then, all hypotheses are just opinions and not worthy of being taken as fact.

Here is an example of what a true drier coin might look like. It took 5 years to produce the damage seen and, you might note, the damage is NOT what is typically described as a drier coin, i.e., a hammered and raised rim. Quite the opposite, in fact. http://imgur.com/gallery/WZoANuU

 

Yeah, dirty shame about that 16-D on the right.

 

Why would they not apply? The core of clad coins is pure copper. I don't understand.

 

Unless I'm shown different, any acid strong enough to undercut the faces of a coin to the extent shown would also be strong enough to erode [or as stated, etched or corroded] the nickel alloy faces to the point of great loss of detail. I don't see that here.

 

The only thing said that bothers me is the hatered towards.Nelson.

 

You DO get the ironic subtext lurking just under the surface of The Simpsons, right? Only the middle child little girl, Lisa, who has every excuse to be up to her ears in neuroses, is even marginally sane. EVERY OTHER character is ripe for the looney bin. Maybe Nelson most of all.

 

So true

 

The information I provided in post #15 is from the Copper Development association Publication 106 Corrosion resistance of Copper and Copper alloys. It is a table that lists and number of substances and whether copper and various copper alloys will react with them. It's used by engineers and designers to decide if they want to use the metals in specific environments. I listed the common acids that not recommended to be used near copper but are OK with copper nickel alloys.

What more do you want?

 

Soaking in acid does not wipe out the detail on a coin, even when the acid attacks the metal strongly, because it works on the entire surface evenly. Copper cents can be reduced to nearly paper thickness and still retain much of their detail. In the case of acid soaked buffalo nickel the acid will even RESTORE details that have worn down to the point where they were no longer visible. In the case of acid soaked clad coins, that haven't had the edge crushed down as the OP coin here, you can still see the reeded edge on the copper even when it is well back from the edge of the coin. Why because since the acid works on all the surfaces evenly the reeded pattern is retained even as the copper is dissolved away.