Cleaning Steel Pennies

Gary talk about "reprocessed coins" - how does that work and what will that do to the collect-ability values of the coin? How do you distinguish the two? Which would value more?

I went to a coins show yesterday and one seller tried to sell me a 43 pennies and said that it's "original, not reprocessed"; however, I saw there are some reddish at the inner edge of the rim....

Thanks.

Transmission fluid works on steel coin

I've got a steel cent that I think was reprocessed. It's shiny, no scratches or lines, but the details are smoothed over (kind of like the 65, 66 SMS cents, but thicker looking).

My guess is that it was actually re-plated with a new thin layer of zinc. I would be easy to do.

As noted the greyish stuff is Zinc Oxide. The intent was back then, in 1943, was to Zinc coat the cents to stop the steel, not iron, from rusting. Iron is pure Iron and these cents were made of steel. Steel is in reality a mixture of metals, not a compound. This also means that unless the mixture process is not done well the composition can vary meaning some will rust more than others. Regardless, although Stainless steel was known at the time, it was just not economical to use this so they just coated the steel with Zinc. Zinc,like Aluminum and some other metals, when Oxydized holds the Oxide to the metal to a fairly good degree. Entire Buildings in Chicago were constructed with Steel like this and the steel is on the outside of the structures and still looks like the day the built them. This means that the greyish coating on your coins is ment to be there and removing it would start the process of Oxydation all over again plus since the layer of Zinc is minor, you may end up exposing the Steel to Oxygen which will form the reddish material called Iron Oxide. Also, pending on the amount of Iron present in the Steel and the amount of Oxygen present, there are two different forulae for the end results.
In summation of this boring thread I would suggest you do nothing to any of the coins that only show greyish discolorations. If I were you I would sort these out and put them in plastic type rolls.
The ones with actual RUST has already lost much of the protective Zinc, so as some have noted the best thing now is a little Oil. Any type at all will suffice. WD-40 would clean them up a little and leave a coating to some degree. You must remember there is not a really big value on most of the 43 Steel Cents since many were made, no one is interested in them, most look like yours and some still turn up in change.

I forgot add an warning label to my post .

Always wear Safety Glasses to cover your eyes and use Rubber gloves using this acid I am talking about. Its bad stuff for sure and will burn you if you get on your skin. If under 18 get your parents to help you dip the pennys in acid like I am talking about. The more the acid is diluted with water the stuff is safer for sure.

This acid will not eat plastic since you need an plastic containtor to put acid in an containor. Dont use an metal containor it will ruin it. I use spray paint containor tops to dip my pennys. Reason it has an small insert in there. If spilled it will stay inside the plastic containor.

Just be safe with stuff for sure.

Regards Chevrolet454ss

Muratic acid is very powerful stuff and fairly concentrated. It is not something to play around with

quote:

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The more the acid is diluted with water the stuff is safer for sure.

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If you do experiment with muratic acid and you want to dilute it always remember this safety rule. Always add acid to water, Never add water to acid. The reason is adding water and acid often releases heat and can cause the mixture to pop and "spit" giving off a shower of droplets. If you add acid to water the droplets will be mostly water, but if you add water to acid the droplets will be concentrated acid.

So I've made up groups of coins and am trying a variety of things to clean this group of badly damaged coins.

The results so far;

Soaked in warm soapy water - This didn't seem to do any good.

Soaked in acetone - This didn't do much of anything one way or another.

Soaked in olive oil. - The coins are still soaking. No obvious difference yet.

Ultrasonic cleaning - Believe it or not, this has made a huge improvement in the coins appearance. The ultrasonic waves (tiny bubbles) removed most (if not all) of the "zinc dust" and even some of the underlying rust. The problem is that it took thirty minutes to clean 15 pennies! I don't think I have the patientce to do the few hundred I now have.

Here's is what hydrochloric acid does to zinc. This is a modern cent, with two small spots filed off to expose the zinc.