A Coin Dipping Question. Maybe really a Dumb Question.
Fairlaneman
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You have a coin that is completely covered with tone and gunk. You decide that the coin needs a little help so you dip the coin. When you are done with your dipping the coin still has a lighter same type tone present on it.
Here is the question. Have you removed some of the metal, which would happen if the coin was dipped to pure white, or have you left all of the metal on the coin and only removed a layer or two of the tone which has built up over the years?
Really I do not know the answer so any help is appreciated.
Ken
Here is the question. Have you removed some of the metal, which would happen if the coin was dipped to pure white, or have you left all of the metal on the coin and only removed a layer or two of the tone which has built up over the years?
Really I do not know the answer so any help is appreciated.
Ken
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In honor of the memory of Cpl. Michael E. Thompson
If the "gunk" is just dirt or other things stuck to the coin, and not the coin itself, then, no metal is being removed.
If you are removing tone, then yes metal is removed.
When metal tones, the oxides are really ceramics. (metal turns into a ceramic). When you dip it, the tone, which use to be metal comes off, so yes, in a way metal is being removed.
<< <i>Here we go again and maybe Tom will answer, isn't dipping the same as using acetone? >>
No, absolutely not, dipping is the application of a mild acid.
<< <i>You have a coin that is completely covered with tone and gunk. You decide that the coin needs a little help so you dip the coin. When you are done with your dipping the coin still has a lighter same type tone present on it.
Here is the question. Have you removed some of the metal, which would happen if the coin was dipped to pure white, or have you left all of the metal on the coin and only removed a layer or two of the tone which has built up over the years?
Really I do not know the answer so any help is appreciated.
Ken >>
First you need to understand that toning is oxidized metal; thus, when you dip the coin you are removing that oxidation. What most people here don't understand, is that if you take a full luster untoned coin and dip it, no metal is removed (because there is no oxidation).
<< <i>
<< <i>You have a coin that is completely covered with tone and gunk. You decide that the coin needs a little help so you dip the coin. When you are done with your dipping the coin still has a lighter same type tone present on it.
Here is the question. Have you removed some of the metal, which would happen if the coin was dipped to pure white, or have you left all of the metal on the coin and only removed a layer or two of the tone which has built up over the years?
Really I do not know the answer so any help is appreciated.
Ken >>
First you need to understand that toning is oxidized metal; thus, when you dip the coin you are removing that oxidation. What most people here don't understand, is that if you take a full luster untoned coin and dip it, no metal is removed (because there is no oxidation). >>
Maybe this is what I need to get clear. If you do not get to the bottom of the oxidation, ie making the coin pure white, are you really removing metal layers? I understand to a certain point you are removing possibly some metal. Anyway I think I understand it.
What confuses me is the premis of waxing a car. When you wax the car you remove a certain amout of paint, same as tone on a coin, but you have not reached the metal to do it any harm.
Ken
<< <i>In general, I believe very deeply toned coins are not good candidates for dipping since the layer of oxidation is fairly deep and most likely a dip would either not fully remove the toning or would strip the coin to a dull surface. >>
Yup. I learned that lesson the hard way.
Worry is the interest you pay on a debt you may not owe.
"Paper money eventually returns to its intrinsic value---zero."----Voltaire
"Everything you say should be true, but not everything true should be said."----Voltaire
<< <i>
<< <i>You have a coin that is completely covered with tone and gunk. You decide that the coin needs a little help so you dip the coin. When you are done with your dipping the coin still has a lighter same type tone present on it.
Here is the question. Have you removed some of the metal, which would happen if the coin was dipped to pure white, or have you left all of the metal on the coin and only removed a layer or two of the tone which has built up over the years?
Really I do not know the answer so any help is appreciated.
Ken >>
First you need to understand that toning is oxidized metal; thus, when you dip the coin you are removing that oxidation. What most people here don't understand, is that if you take a full luster untoned coin and dip it, no metal is removed (because there is no oxidation). >>
I disagree......When toning forms, the outer most layer of metal is combining with oxygen and possibly sulfur to create a new compound. This new compound still contains the original metal atoms, and when you remove that layer, those metal atoms go with it. If you use coin dip on a bright white coin, and the particular metal (90% silver and 10% copper) is dissolvable in that acid, then you will remove metal.
If dipping a bright white coin never removed any metal, then it would be impossible to overdip a coin which we know is not the case.
Addendum...I looked up the MSDS for E-Z-est, a commonly used coin dip. It contains sulfuric adid which is not reactive with silver. However, copper is highly reactive with sulfuric acid, and I'm guessing that it is the copper in the 90% 10% silver copper allow that is being removed which eventually will change the structure of the flow lines, therefor muting the luster if done repeatedly.
<< <i>Is the use if acetone also considered dipping and does acetone also remove metal albeit at the microscopic level? >>
I don't consider it dipping. Acetone is an organic solvent, and metal is not organic and therefor should have no effect on the metal.
But what if started with a car that had no paint? The metal would oxidize (rust), and in removing the rust you would be removing some of the metal.
Now you're just grasping at straws. I suggest you take a BU Roosevelt dime and dip it 100 times; it will still have plenty of luster afterward.
<< <i>Is the use if acetone also considered dipping and does acetone also remove metal albeit at the microscopic level? >>
Nope. I did a little test. I took a baggy as heck (61-62) but VERY lustrous Morgan Dollar with toning on it, threw it in a metal jar, filled it with acetone, put a lid on it, and let it sit in the jar.
For a month.
Guess what? It came out of the Acetone bath with toning and luster totally intact, no different than when it went in there.
<< <i>"Addendum...I looked up the MSDS for E-Z-est, a commonly used coin dip. It contains sulfuric adid which is not reactive with silver. However, copper is highly reactive with sulfuric acid, and I'm guessing that it is the copper in the 90% 10% silver copper allow that is being removed which eventually will change the structure of the flow lines, therefor muting the luster if done repeatedly. "
Now you're just grasping at straws. I suggest you take a BU Roosevelt dime and dip it 100 times; it will still have plenty of luster afterward. >>
So what you're saying that if I take a lightly toned coin and dip it white, once that thin layer of toning is gone, repeated dips will never change the appearance of that coin?
<< <i>
<< <i>"Addendum...I looked up the MSDS for E-Z-est, a commonly used coin dip. It contains sulfuric adid which is not reactive with silver. However, copper is highly reactive with sulfuric acid, and I'm guessing that it is the copper in the 90% 10% silver copper allow that is being removed which eventually will change the structure of the flow lines, therefor muting the luster if done repeatedly. "
Now you're just grasping at straws. I suggest you take a BU Roosevelt dime and dip it 100 times; it will still have plenty of luster afterward. >>
So what you're saying that if I take a lightly toned coin and dip it white, once that thin layer of toning is gone, repeated dips will never change the appearance of that coin? >>
Yep, unless you wait for it to retone.
What chemical form are you saying the metal is removed?
Thiourea converts the tarnish (Ag2S) to H2S and elemental silver which is redeposited on the coin as I understand it. --Jerry
by sulfuric acid.Don't take my word for it, look it up in an inorganic chemistry text. Weimar White discussed oxidation and "native" metal in coins to some degree in his books on coin chemistry as well.
Stripped off is oxidized metal/toned surface and metal both oxidized and still in reduced unoxidized form
Well, just Love coins, period.
<< <i>Here we go again and maybe Tom will answer, isn't dipping the same as using acetone? >>
Only thing in common is they are both liquids, otherwise they are not similar.
<< <i>Obviously closed minds are opened only with difficulty. Metal IS removed by dipping, oxidized or not.Silver IS oxidized
by sulfuric acid.Don't take my word for it, look it up in an inorganic chemistry text. Weimar White discussed oxidation and "native" metal in coins to some degree in his books on coin chemistry as well.
Stripped off is oxidized metal/toned surface and metal both oxidized and still in reduced unoxidized form >>
Silver is not oxidized. Do you have a scientific background? --Jerry
edit: Some silver is removed by the toning process. This silver is suspended in the form of AgS (silver sulfide), the primary constituent of the toning (tarnish) layer. If when reduced, the silver isn't redeposited onto the coin (which it may not be if the tarnish is thick or there is gunk in the way) then that silver may be released into solution.
<< <i>
<< <i>Here we go again and maybe Tom will answer, isn't dipping the same as using acetone? >>
Only thing in common is they are both liquids, otherwise they are not similar. >>
Correct, Acetone is an organic solvent that will dissolve some forms of gunk on coins.
Dipping is a done with an acid, mostly thiourea, that chemically gets rid of AgS by reducing it to Ag and H2S. --Jerry
and many combinations
dirt, oil, grease, chemicals, contaminants, metal/new chemical combinations
some just set on top of metal
while some react with metal - changing metal into a different form - and some do both
PVC does both evetually - it sits on top of metal, and eventually etches metal and changes the surface structure where it attacks
back to your question
when you ask about dipping the coin, ask yourself what it does to what
if you soak a coin in water for a day, what will happen or be the result (will any of the above mentioned things be affected and how?)
now substitue water in the above with some other things
like - soapy water, mineral oil, olive oil, vinegar, paint thinner, acetone, acid (many types), base (many types), .....
you can add to the above list of items that generally will take various things off
and don't forget when done dipping in the above things, there may be a film of the stuff that is still working
another category of stuff that some consider is soaking in things that will put stuff on - but that is an area most would agree is bad
so if you soak something in water, is it dipping or did it get wet - you decide were to draw the line