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  Polishing and restoring luster to space medals

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Author Topic:   Polishing and restoring luster to space medals

Posts: 73
From: Carlsbad, CA
Registered: Nov 2007

posted 09-10-2008 05:24 PM     Click Here to See the Profile for wmk   Click Here to Email wmk     Edit/Delete Message   Reply w/Quote
Can anyone comment on whether or not medallions in general should ever be polished or cleaned? And in particular silver medallions (since they can tarnish)?

I assume it is best to just leave them alone (and perhaps the aging is part of the appeal), but I am curious what this group's opinion is? Would any kind of polishing (even gentle) detract from the value?


Posts: 597
From: Wellington, New Zealand
Registered: Mar 2003

posted 09-11-2008 02:33 AM     Click Here to See the Profile for TRS   Click Here to Email TRS     Edit/Delete Message   Reply w/Quote
My advice (and it is personal opinion) to leave them alone unless you have a professional conservator do them. Even the conservators sometimes advise that the cleaning is a bad move because the depth of the buildup in the pattern on the medallion can either leave an uneven finish (i.e. some bits get clean and the tricky bits stay dirty), or you need to be a bit more 'aggressive' to clean which risks damage to the medallion.

If you do make a call to clean one, I strongly suggest that you immediately put it in an airtight container to prevent any further tarnishing.


Posts: 73
From: Carlsbad, CA
Registered: Nov 2007

posted 09-11-2008 11:31 AM     Click Here to See the Profile for wmk   Click Here to Email wmk     Edit/Delete Message   Reply w/Quote
Thanks Craig. That was similar advise given to me by a coin and stamp dealer. He basically said that aging is often part of the "appeal" so I will probably just leave them alone.

Rocket Chris

Posts: 228
Registered: Nov 2009

posted 09-30-2010 05:07 AM     Click Here to See the Profile for Rocket Chris   Click Here to Email Rocket Chris     Edit/Delete Message   Reply w/Quote
Well probably there are also some collectors out there who owned a coin in a not really "mint" condition or even more worse. So this guide should be like a tutorial and hopefully there will be some more tricks and tips how to "pimp" a recently owned coin. So feel free to add your guides.

I'm presenting some "how to's" as I did it with several of my coins. Any ideas are welcome.

Lesson 1: Polishing

Some coins, especially aluminium alloy ones like the MFA Apollo 8, Enterprise, Skylab, ASTP... whatever... have a very "tender" appearence. So most of these coins I bought had scratches and where just dulled. One option to slick up these coins is normal toothpaste and a soft tissue. Just gently polish the coin and you'll see the medal shines again. For bigger, deeper scratches use silver polish. First drop a little bit of water onto the coin, take the silver polish and also a fine and soft polish tissue. Just polish such bland coins very gently. If you push to hard you might destroy the embossing. So handle everytime with care.

Lesson 2: Brighten it up

Just take an old copper coin and you'll see the coin got dark due oxidation and dirt and use. Also some bronze coins get darker after a time. Now here's a simple trick to bring back the old shine without any chemicals or agressive methods.

Step 1: Clean the coin with a wet tissue

Step 2: Take a full spoon of normal salt (you'll probably find it in the kitchen) and place the salt onto the coins side you want to bleach.

Step 3: Get a fresh citron, cut it in the middle

Step 4: Now Press the citron and drop some citron juice onto the "salted" coin.

Now, you'll have a natural bleach effect. The acid of the citron in combination with the salt dislodges the oxidaive layer. The coin gets back its fresh brightness.

You can repeat this bleaching several times if you want to light up a bronze coin.

Here is an image of my framed STS-88 MFA. I made this bleaching several times and now the coin "glows" from inside out. You can see that the inner point is lighter and gets darker to the outer diameter:

Gently wash the salt away and dry it with a wet tissue. You also can seal the coin with isopropanol, special alcohol you get in every drug store or even at the pharmacy.

Before you bright up your space flown coin, or collective coin, try it out on a normal dollar, copper coin or any else coin you'll find in your wallet.

Lesson 3: Highlighting

So some coins are made of darker metal or they got a dark coating. Therefore the embossing just gets lost while you take a look from a farther distance. So you can accent the embossing of the coin. Now, for this purpose you need also metal polish, an eraser and a soft tissue. Take some metal polish and add it onto the coin. Now take the eraser and place it with the flat side onto the coin. Make gently circulating moves with the eraser on the coin. The metal polish between the eraser an the coin just highlights the embossing.

The darker ground of the coin won't be touched. So you just polish the increased lettering.

Clean up the coin with an middle hard teeth brush.

Here is an image of my 50th anniversary NASA coin. Bevor polishing it just had a simple embossing. Now the lettering raises from the rest of the coin.

Now with this option you also remove the coating. You can seal the coin with a clear, transparent varnish. Bevor varnishing use the isopropanol for cleaning it up again and wait until the coin is dry again.

Before you want to highlight and accent a coin try it out on another one. Once you've removed to much coating from the coin ist not possible to make the highlighted areas dark again.

Bronze coins can be darken with high concentrated vinegar. The vinegar benefits a new oxidation. But this takes also a long time.

Editor's note: Threads merged.


Posts: 1580
From: Atlanta, GA, USA
Registered: Feb 2007

posted 09-30-2010 06:10 AM     Click Here to See the Profile for garymilgrom   Click Here to Email garymilgrom     Edit/Delete Message   Reply w/Quote
Your 50th Anniversary coin looks beautiful. Well done!


Posts: 352
From: San Jose, California, USA
Registered: Mar 2002

posted 09-30-2010 05:50 PM     Click Here to See the Profile for mikepf   Click Here to Email mikepf     Edit/Delete Message   Reply w/Quote
Just a cautionary note, I'm sure these cleaning tips are good advice from a visual perspective, but cleaning any coin or medal has a great potential to ruin its value. Original patina is highly valued in coin and many other antiques collecting.


Posts: 273
From: Texas * Earth
Registered: Apr 2011

posted 08-01-2013 08:00 PM     Click Here to See the Profile for Cozmosis22     Edit/Delete Message   Reply w/Quote
Originally posted by wmk:
Would any kind of polishing (even gentle) detract from the value?
Personally, prefer to see the image as the artist intended, therefore clean away the shadowy patina on the silver.

Depending on the condition of an old medal, many not well-preserved; most of them can be cleaned up pretty nice with Windex and a toothbrush.


Posts: 121
Registered: Jun 2011

posted 08-01-2013 08:56 PM     Click Here to See the Profile for tnperri   Click Here to Email tnperri     Edit/Delete Message   Reply w/Quote
First, if they are for your personal pleasure then I say clean them. I clean my medallions because I like the beauty of the medal and want to see it.

This is a personal decision and should depend on how you like your medallions.

All times are CT (US)

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