Tried two different ways to clean some Roman coins I found in a field last spring

Hannah Flores · 2026-03-13T14:40:10.695228+00:00

I had a batch of about 15 coins from a site in Norfolk, all pretty crusted over. For months, I was just using a soft toothbrush and distilled water, which was very slow and didn't do much. Last week, I tried a short soak in a 5% citric acid solution for just 30 seconds, followed by the brushing. The difference was huge. The acid gently loosened the hard dirt without hurting the metal, and I could finally see details on three of them. It saved me hours of careful picking. Has anyone else had good results with mild acids on copper alloys, or is there a better method you like?

grant_gibson6mo ago

Wait, you just left them in a field for months? @gonzalez.vera might be onto something with the olive oil, but I'm stuck on the part where you had a pile of Roman coins just sitting around.

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gonzalez.vera6mo ago

Ever try a drop of olive oil for the really stuck bits?

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dylan_stone335mo ago

Honestly, I was always scared to use any acid at all. I thought it would eat the coin. But seeing your results with such a short soak makes a lot of sense. It's not about dissolving the crud, just loosening its grip. I might have to give that a try on my next crusty find. What's your mix ratio for the citric acid?

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