Cleaning journal

[Overlord]

I recently obtained a small lot of later Roman bronze to try out cleaning and thought I would report the progress here as I go about it.

Day 1: Soaked the coins in a small amount of distilled water.
Day 2: The lose dirt had come off. I left the coins in a mixture of trisodium phosphate (TSP) and warm water for 5 minutes.

Cleaned the coins lightly with an old toothbrush and wooden toothpicks. Chunks of dirt came loose off some coins, while others remained stubborn.

I am soaking the coins in fresh distilled water. Will check on them after a week.

[Figleaf]

Good luck. Looks like a promising lot, with much detail remaining. When you are through with the water, try an acetone rub, just to make sure there are no chemicals left. I am thinking of artificial fertiliser...

Peter

[Overlord]

I took out the coins today and performed another round of cleaning using the toothbrush and wooden toothpicks. This removed bits of soil struck to the surface of some coins. The heavily encrusted ones have showed almost no response.

I have soaked them in fresh distilled water till next week.

[Overlord]

The progress has been rather slow, so I moved to the fiberglass brush. Most coins can be attributed, but still have spots that need cleaning.

[Figleaf]

Have you seen this thread?

Peter

[Overlord]

Have you seen this thread?

Peter

Yes. I had come across that PDF while Google searching before I started. Thanks.

[Overlord]

Another low-quality lot for cleaning fun:

[Overlord]

The first batch of coins is going under the scalpel. Nice way to spend a rainy day.

[Figleaf]

Eek! Sharpies.

Neat knife set, but it's for wood, not coins. How about a test with electrolysis first?

Peter

[Overlord]

Eek! Sharpies.

Neat knife set, but it's for wood, not coins. How about a test with electrolysis first?

Peter

I am removing encrustation, so the hardness of the blade isn't an issue. Electrolysis is faster, but will strip any patina off the coin. Besides, I love slow, deliberate mechanical cleaning. That's the whole reason I started this exercise. Under the microscope, the process feels like excavating an ancient statue. The coins are low-grade, cheap, and very common, so it won't be a great loss if I make a mistake.

[Overlord]

The first coin in reply 3. Still WIP, but I have managed to thin down the tough resin-like deposit:

[Figleaf]

Looks good, Overlord. What's happening in front of the emperor's nose? Just the light? Scratches?

Peter

[Overlord]

What's happening in front of the emperor's nose? Just the light? Scratches?

Peter

May be the low-res photo taken in fading daylight on a rainy day. Comparing with the first image, I only see most of the white patches gone. I made two tiny dents too small to see with the naked eye. Even those can be "smoothed over".  (Back in college, if a nerve got cut during dissection, we used to "tie" the cut ends and trim the ends such that it looked like a ganglion.  )