Rust deposits

[Nightvision]

Hi again,

I was gifted another mixed bag of predecimals this month. Got all excited. First item out of the bag was ... a rusted dog tag. Heart sank.

I now have a bunch of coins with rust deposits partially obscuring everything. I attacked a few with acetone, a cotton wool bud and a cocktail stick to see what would happen. After three hours work I was able to rescue most of a german 5 pfennig but got quite high during the process so I'd rather not repeat it. (I'm kidding, the room was ventilated - I just got really bored).

Next step, olive oil bath. Or will that most likely be a waste of time too? All tips gratefully welcomed.

[Coinery]

Sadly, I haven't found anything that will remove rust spots without obliterating the coin!

I even tried dipping a coin to death once...still no good! Sorry!

[Nutsaboutcoins]

Sandpaper and hammerite seems to have worked well with my rusty gate

[Nightvision]

Thank you both. I will proceed, in the interests of science and under the assumption I probably can't make matters worse!

[Coinery]

If you come up with any satisfactory solution, please let us know!

[bagerap]

Something to try. Lightly rub the rust with an ordinary pencil, soft lead preferred. Now take a pencil eraser and rub off. It takes off a layer of the looser corrosion without any perceivable damage to the coin. Repeat as required.

[bagerap]

Oh, and your fingers will be covered in shiny grey greasy graphite for hours. Wear gloves.

[colonialjohn]

Iron is normally removed best with an acid than an alkaline cleaner. Having said that both as you know can change the patina of the coin. If I was in this situation you just need to separate out low value/high value. I would use a very weak organic acid solution say 1-5% like oxalic acid or confer with a chemist locally who can give you more options of organic acids (i.e., mild by nature as compared to mineral acids like hydrochloric) that are available in a hardware store.

It works FINE.

John Lorenzo

Numismatist

United States