Cleaning A Dirty Owl

I would love to have an Athena/Owl Tetradrachm, but don't want to put out the money just yet. I saw this coin - a small bronze - on fee-bay and bought it:

After receiving it, I soaked it in water and used a cut-off toothbrush, but it didn't seem to make much difference. I decided that since I hadn't paid very much, I couldn't loose very much, so I soaked it in a potassium hydroxide solution and used a copper brush on it gently.

Keep in mind that I am really awful at taking pictures, but this is the outcome:

Much darker than this, just a lousy picture taker.

 

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You'd be run out of town on a rail, Kentucky, in the more modern forums, but I think the 'ancient fellows' will adore you.

 

Almost all ancients have some degree of cleaning. I think potassium hydroxide is one of the agents in MS70.

 

wow. the obverse and reverse switch sides! like a magnetic pole reversal!

 

I said I was lousy with pictures!!!

 

Good Lord, they're not at all half bad.......

 

I think you did a commendable job (keep in mind that I no longer clean coins because I'm so bad at it). The details, once cleaned, seem sharp. I would like to see an image reflecting the true color. Overall, two thumbs up.

 

High praise indeed and I will keep trying till I get a good picture.

 

I would say you did a good job at cleaning that coin and taking the picture. Takes a lot of patience.

 

I failed but every so often you have to try the impossible. Of course it is no longer a photo of the coin but more of a rendering of the type with plenty of pits.

 

I tried editing the image as well with no good luck. Best if @Kentucky can try another image

 

This gets the color better, but the coin is somewhat darker:

 

Would you say the potassium hydroxide removed all the dirt and patina and left bare metal?

Do you have any feel for whether any metal was removed as well?

The pitting on the cleaned version could easily have been hiding under the patina and gunk.

John

 

Mostly agree that the porosity was covered by the crud (unwanted patina). Don't think much if any metal was removed since the solution didn't develop much color and compounds of copper are colored. I have noticed that cleaning with chemical solutions often leaves a grainy surface. Gonna' try one more pair of pics on a white background to see if I can capture the true appearance.

 

IMO Stripping down to bare metal for more detail is probably not the best. I liked the 2000 yeat old patina that is now gone forever.

 

Sorry but look again, almost no details visible. Not quite down to bare metal yet. I can wait another 2000 years.

 

I can't comment on your cleaning as I have zero experience cleaning ancient coins. I do have a low grade example of your coin. This coin was gifted to me by a friend & I like the little owl.

 

When a bronze coin has a patina so thick it obscures the design (or when it is coated with thick dirt or gunk) sometimes the outer layers can be removed using a soft brass brush or fiberglass pen (use with proper safety gear). This can leave the pits and low spots filled in with patina while exposing more of the details. This is an alternative to chemicals which are harder to control how much they will remove. People sometimes have success with dabbing chemicals on specific areas with a q tip. The more I do this the more I like mechanical cleaning versus chemicals but every ancient coin is different.

I appreciate you sharing this with us.

 

Cool thread ... oh, and great progress on that sweet OP-owl (awesome effort)

... I love you guys ...

Ummm, but Kentucky => why do you have those circular photo shots? (are the viewers supposed to think that we're viewing your coin through binoculars?)



... again, great effort (keep-up the good work)

 

OK, just because you take such awesome pictures, don't laugh at me. Using Photoscape, round cropping and putting two on one view is stretching my abilities.