How To Clean & Preserve Your Metal Detecting Finds

[Steve Herschbach]

Read the full article by Dr. Tones at Treasure Talk

Here is the accompanying video...

 

[MikePfeiffer]

Thanks for the info Steve. I don't clean my finds very much. However. I have been using electrolysis for years. Great for cleaning rusty surfaces. I also us washing soda to replace baking soda in some applications.

[Steve Herschbach]

An ultrasonic cleaner does wonders for gold nuggets and jewelry. Anything that might have dirt lodged deep in crevices.

[MikePfeiffer]

I have used industrial ultrasonic cleaners in the past. Thought about getting on for home use.  Any suggestions?

 

[Steve Herschbach]

I got an Optima 420 in 2014 and have been very happy with it. My wife was even happier - she uses it more than I do to clean her jewelry. But still there when I need it. There are smaller, cheaper ones but I sometimes need to clean some fairly large specimen gold.

[LukeJ]

5 hours ago, Steve Herschbach said:

An ultrasonic cleaner does wonders for gold nuggets and jewelry. Anything that might have dirt lodged deep in crevices.

I have been cleaning my nuggets in a super-saturated solution of baking soda and hydrogen peroxide, with a splash of vinegar for good measure.

Basically, I just take a shot glass ( I'm in Arizona, most of our nuggets fit in a shot glass ) and fill it halfway with H2O2.  Then add enough baking soda so that when stirred vigorously there is still a layer of undissolved baking soda on the bottom of the shot glass.

Place your nuggets in the solution and after about 15 seconds or less, you will see some bubbling and dirt will start to float up to the top.  

Later, when the bubbles die down a bit, carefully add a small amount (maybe a teaspoon) of vinegar to the solution.  It will bubble and overflow if you add it too fast.  Vinegar and baking soda will neutralize each other, but there will still be extra baking soda at the bottom of the glass.

I'm not savvy enough with chemical equations to write it all out, but here's what I think is happening....

The hydrogen peroxide is just water with an extra oxygen atom.  When it breaks down, the oxygen bubbles off and you're left with water.  By adding the baking soda, you're now getting the cleaning action of baking soda with the addition of an oxidizer in water.  The vinegar is neutralized (no longer an acid) by the baking soda.  When this happens, the acetate ion is left in solution with the other components.  Not sure why this makes it better, but you'll see that the bubbles increase after the initial reaction when the vinegar is added.  I just think it's an ionic solution and the more the better as far as having ions to react with whatever is sticking to the gold. 

This method is very effective and yet benign.  You can stick your fingers in the solution and not have a second thought about dumping down the sink when you're done.

Personally, I like the way this method cleans my gold.  It gets the dirt off and doesn't change the gold other than that.

I haven't tried cleaning any relics or coins with this method, so use your own discretion when it comes to those items.

Here's a couple pics of some recently found nuggets.  All of these pieces came from the same area within a 100 meter stretch.  Some were found in dark red clay.  The shiny dime pic shows what the red clay nuggets looked like after only a 'spit shine'.  

Luke

[bado1]

I'm with you, Luke...I'm not a fan of nuggets cleaned with the acid bath method. They look like museum pieces to me. I like getting the dirt off of them without changing the " out of the ground character". Thanks for sharing your method. I'll give it a try.

Dean

[GB_Amateur]

A 'bible' (don't know if it's the only one) on this subject is Cleaning and Preservation of Coins and Medals by Gerhard Welter, Sanford J. Durst (publisher), Rockville Centre, NY (1976).  I bought this at a metal detecting online outlet but can't remember which one.  I think this was written in German but my copy (Durst pubished) is in Engish.  It was created to cover European coins from many centuries but it is surpisingly (to me) applicable to US coinage.  I guess there's been a lot of collaboration/cross-study of coin planchet composition across at least one ocean.

There is quite a significant difference between making a coin look pretty for the layman and making it presentable to a numistmatist (coin collector).  Even micro-scratches which are revealed by careful viewing through high magnifcation can affect a numismatic-value coin significantly, in the wrong direction.  Even rubbing a coin with a cotton cloth can introduce micro-scratches.  Worse is rubbing a dirty coin since the dirt itself is an abrassive.  I cringe watching videos of metal detectorist rubbing the coins they pull out of the ground because they don't have the patience to take them home and soak them.  They just have to know what they've found.

I agree that if you have something with little or no numismatic value AFTER it is cleaned, then go ahead and make it look nice on your wall/coffee table.  It doesn't make any sense to spend $50 to $100 (just guessing here) for professional restoration of a coin worth $5 after that process.  To emphasize, an ugly coin which would be worth $5.00 after professional quality cleaning but worth next to nothing in its current state can't be hurt by brute force (for example, abrasive) cleaning.  The key is to know the potential value of the find before taking the first step.  Numismatists are adament about naturally looking surfaces, whether uncirculated ("mint state") or circulated.  They are sleuthes who would make Sherlock Holmes seem like a 5-year-old.  They cannot be fooled; they know which coins have been cleaned and which haven't, and the difference is huge.  The worse the handling the more value is lost.

Just like metal detecting, cleaning coins is a very complicated subject if you really want to be an expert, and although that's not a requirement in all cases, it certainly is, in the long run, if you want to maximize your equity.

[57buick]

Yea I bought an ultrasonic cleaner for corroded coins, it works pretty good