A New Coin Cleaning Project. 1803 Large Cent

Even for museum professionals,
coin cleaning and preservation can be somewhat of a lottery.

Should be fun, like this kinda stuff.

the coin arrived about an hour ago. I'm not usually this excited to get a package but this thread has been on my mind and I was excited to see what I would be working with.

i shot pictures of a couple angles so that you could get a feel for the color and surface. the good parts are more attractive than I had hoped. its pretty shiny confirming its been cleaned in the past. that zigzag does appear to be glue of some kind so I'm hopeful that it will come off with either water or a solvent. here it is:







first thing I want to do it hit it with some solvents and see what happens. I took it out to the garage. it is a large and well ventilated space that is great for working with chemicals. here you can see one of the more important tools. gloves. I dont want these chemicals on my skin. I dont want to breathe the fumes in.


these are the solvents I use the most. both came from home depot. you can also see some of my other hobbies - my pool table and my rag top split window beetle project.


i grabbed a cotton swab and dabbed some xylene onto the coin. I dab vertically. never horizontally. never scrub. scrubbing is how you hairline the coin. the swab isn't hard enough to scratch copper but the bits of debris it collects can be.

i was hoping that all that blue green would wipe off. we werent that lucky. barely anything came off. this leads me to believe that the previous owner had already done something similar. thats a bit concerning. this stuff might be hard to remove. top of the swab was used. bottom is unused.


next step is a soak. I'm going to leave it to soak in xylene over night. maybe for a couple days. I put the coin in a baby food jar and sealed the lid. that will keep the solvent from evaportaing and keep fumes from becoming a problem.


sometimes these things can take months.

total time so far?

5 minutes work time and maybe 40 minutes total time with documentation, uploading photos and typing this up.

@allcoinage - I'm not sure I can do much for that one. I find that I have a hard time working on coins I dont know well. its a lot easier for me to excavate gunk without damaging the metal if I know where the metal should be. I'm not very familiar with that coin. I do think that would be a great coin to practice your own skills on though! I think the spots around one penny would come off pretty easily. I'm less certain about the other side. I think there will be some significant metal damage under all the dirt/grime/whatever that is.

Think you are right with damage on the obverse side of penny but I still will try second process that your doing soaking this coin pure acetone 100%, just see the outcome, well it is a 1935 Australian penny I found it buried on a construction site while I was working there.good luck with your coins carrscoins.

Sounds like it's progressing nicely, very good to hear!

yes. museums clean coins. sometimes well. sometimes quite poorly. check out the cleaning job the Smithsonian did on this one:



there are many techniques used by many different people. I like to start here because its reliable, cheap and non destructive. I dont know whats on the coin and I dont know whats been done to it in the past.

do you have a specific article or piece of research you would recommend?

in the imortal words of Michelangelo - ancora imparo - everyone should always be looking to learn more

I am enjoying the updates. Thanks for sharing your process.