Given the recent hot weather, a Question: What does exposure to high temperatures do to coins in alb

SanctionII · July 24, 2006 3:07AM

In parts of the SF Bay Area record high temperatures were set this past weekend (I was driving around and the digital readout for the temperature was 116 degrees). That got me to thinking what prolonged exposure to such high temperatures would do to coins (silver, copper, nickel, etc) in albums and rolls (i.e, coins in contact with material that may not be inert)?

Your thoughts please?

OffMetal · July 24, 2006 3:14AM

Lucky you!

We were dying in 118-120 degree heats in Arizona

oreville · July 24, 2006 3:15AM

rolls - nothing as long as humidity is not a factor. Heat and cold are no problem for coins in tubes or rolls. High humidity is the killer.

albums: More of a concern. Again humidity or direct, even indirect sunlight is the real concern, not heat. I have seen coins in US Mint packaged proof sets do very well in extreme heat unless direct sunshine or humidity was involved.

ABC123 · July 24, 2006 3:37AM

Keep the Humidity under 60%, you will not have any problems !

MORGANHUNTER2 · July 24, 2006 3:44AM

I wish I could live in a place that has an average temp of 84 degrees during the day with about 20-35% humidity, one where there is no threat of tornadoes or earthquakes,tsunamis,hurricanes, war, acts of terrorism, and oh- low gas prices.

Where does this place exist?

Today in the Phoenix area- 112 for the high- and maybe a monsoon dust/shower.

Thenewguy · July 24, 2006 3:56AM

<< Where does this place exist? >>

In todays world..only in your mind.

carl · July 24, 2006 4:05AM

If you ever took a class in Chemistry you would remember that as you increase heat, you increase most chemical reactions. Humidity with metals is important but mostly old wifes tales as to the reactions that are possible with the metals of coins and humidity. Plastic tube rolls begins to break down with intense heat. If sealed and exposed to heat the cheical properties will eventualy begin to effect coins. Although such plastics as PVC are extreamly stable at high temperatures they will cause some concern with coins and that is where you hear people complaining about some type of PVC coating on a coin. Additional heat will increase the normal reaction of Oxigen with copper. Again, moisture nor sulfur is the toning agent of copper coins at first. Exposed to warm air copper coins will react with O to form CuO2. (Sorry about no lower case 2). Then with the help of the slightest bit of H OH (your moisture) and primarily CO2 (Carbon DiOxide), a dull greenish layer will form none as Copper Carbonate [CuCO3-Cu(OH)2]. Again, heat will increase this reaction of chemicals. Another old wives tales is that the greenish color is from Sulfur. Note, no Sulfur was mentioned. However, in areas where Sulfur rich coal is burned the air becomes full of SO and SO2. This mixes with the H OH in the air creating H2SO3 and H2SO4. As it precipitates if is known as Acid Rain. This will effect the Copper Carbonate and with sufficeint heat will form CuSO4 crystals well used as a vegatation killer. Involvements with Silver, Nickel, other metals are similar in that increased temperatures will also increase chemical reactions with other air born elements and compounds.
As temperatures anywhere drop, the movements of sub atomic particles is reduced and chemical reactions are deminished.

ziggy29 · July 24, 2006 4:53AM

Just set some coins in a Wayte Raymond album and watch 'em turn funky colors!

SanctionII · July 24, 2006 5:00AM

Carl, thanks for the chemistry information. I never took a chem class in college and do not know much of the subject. As far as high school and middle school goes, I vaguely remember studying the periodic table.

I understand that at lower temperatures less motion is present between atoms and subatomic particles; that at high tempuratures more motion is present; that at absolute zero there is supposedly know such movement; and that at temperatures inside suns (or exploding suns) the motion is so great that lighter elements are undergo changes that result in heavier elements (the how and why of this I do not understand). Is my recollection/understanding accurate?

Longacre · July 24, 2006 5:14AM

I want to move to the Southwest. At least it is a dry heat. The golf is great too!

MORGANHUNTER2 · July 24, 2006 6:36AM

I want to move to the Southwest. At least it is a dry heat. The golf is great too!

-------------------------

if your thinking of the Phoenix area- think and read before you jump on that next flight.

Average this time of year- 100+, I'm told it is much nicer come September- but that is about the time the snowbirds are gettin ready to flock back here, so drive time and TEE times will be rough.

I'm still looking for the PERFECT place. and my mind keeps tellin me it's there, it's there!

ziggy29 · July 24, 2006 6:51AM

<< I'm still looking for the PERFECT place. and my mind keeps tellin me it's there, it's there! >>

Uncrowded, great weather, lovely scenery, affordable -- pick any three.

xphobe · July 24, 2006 7:00AM

To really challenge my coin collection, I chose to live in Houston where it's hot and humid. I suppose Baytown or Pasadena might be even worse, where the air contains sulfur from the refineries and salt from the ship channel.

I check my coins from time to time. 25 years and no weird ugly toning or spots so far, although some of my Dansco albums have started to mold.

cladking · July 24, 2006 7:51AM

<< If you ever took a class in Chemistry you would remember that as you increase heat, you increase most chemical reactions. Humidity with metals is important but mostly old wifes tales as to the reactions that are possible with the metals of coins and humidity. Plastic tube rolls begins to break down with intense heat. If sealed and exposed to heat the cheical properties will eventualy begin to effect coins. Although such plastics as PVC are extreamly stable at high temperatures they will cause some concern with coins and that is where you hear people complaining about some type of PVC coating on a coin. Additional heat will increase the normal reaction of Oxigen with copper. Again, moisture nor sulfur is the toning agent of copper coins at first. Exposed to warm air copper coins will react with O to form CuO2. (Sorry about no lower case 2). Then with the help of the slightest bit of H OH (your moisture) and primarily CO2 (Carbon DiOxide), a dull greenish layer will form none as Copper Carbonate [CuCO3-Cu(OH)2]. Again, heat will increase this reaction of chemicals. Another old wives tales is that the greenish color is from Sulfur. Note, no Sulfur was mentioned. However, in areas where Sulfur rich coal is burned the air becomes full of SO and SO2. This mixes with the H OH in the air creating H2SO3 and H2SO4. As it precipitates if is known as Acid Rain. This will effect the Copper Carbonate and with sufficeint heat will form CuSO4 crystals well used as a vegatation killer. Involvements with Silver, Nickel, other metals are similar in that increased temperatures will also increase chemical reactions with other air born elements and compounds.
As temperatures anywhere drop, the movements of sub atomic particles is reduced and chemical reactions are deminished. >>

Excellent post and valuable information.

However it should be remembered that highly reactive metals and those with the
most delicate surfaces are easily damaged by exposure to actual condensation.
This is a particular problem if the coins are stored in a cold area that can warm sud-
denly. Moisture droplets can be the seed of carbon spots or worse as they concen-
trate and move surface contaminants.

This condensation is also hard on packaging materials. Avoid storage in such areas
and leave as little air in the packaging with the coin as practical.

Coxe · July 24, 2006 12:18PM

It has been abnormally humid here in Southern California this month. I have noticed my cups of DampRid in the linen closets and pantries saturated with water in a couple days. Anyone who mistakenly keeps coins in gunsafes or firesafes under such conditions better check on them. Even slabs will turn on you, especially copper and silver proofs.

carl · July 24, 2006 1:08PM

<< Carl, thanks for the chemistry information. I never took a chem class in college and do not know much of the subject. As far as high school and middle school goes, I vaguely remember studying the periodic table.
I understand that at lower temperatures less motion is present between atoms and subatomic particles; that at high tempuratures more motion is present; that at absolute zero there is supposedly know such movement; and that at temperatures inside suns (or exploding suns) the motion is so great that lighter elements are undergo changes that result in heavier elements (the how and why of this I do not understand). Is my recollection/understanding accurate? >>

WOW. For someone that says you never took a chem class, you sure know more than most. I taught Chem in Junior College and I wish I had students with your understanding. As to your understanding, it's correct. The heat and movement use the Newtrons to bombard other atoms to form heavier nuclei.
And this is why heat increases reactivity in the metals of all coins.
By the way are you aware of the fact that as these atoms increase in movement, they expand and make metals larger. Just think with enough heat you could make a nickel into a quarter.
Last statement a joke of course.

Conder101 · July 25, 2006 2:29AM

The reactions in the sun and other stars that convert atoms of one element into another isn't chemistry it's physics. It results from the high temperatures and pressures allowing atoms to be fused together to create heavier elements. It has nothing to do with chemical reactions between the elements. (In general chemical reactions involve the bonding or sharing of electrons in the outer electron shells not the nucleci.)

As temperature rises though the atoms do gain energy and are more likely to react so reactions do tend to proceed more quickly at higher temperatures. Also at higher temperatures the relative humidity may drop, but since warm air can hold more water the absolute humidity may actually rise and there will be more water available for undesirable reactions. The real danger though is if the temperatures change rapidly. High temperatures can cause the air to absorb mort water which can then condense back out on the coins as the temperature dropes again. Rapidly rising and falling temperatures then can cause the metal of the coins to be active and have plenty of water available. Not a good combination.

Cameonut · July 25, 2006 10:34AM

I don't think high temps are good for coins at all. Humidity is also a huge issue as already described.

I was taught as a rule of thumb that for every 10 degrees Centigrade (18 degrees Fahrenheit) the temperature rises, the reaction rate doubles. So all those reactions that are happening at 90 degrees F are going twice as fast as at room temperature. At 108 degrees F they are going four times as fast.

xphobe · July 26, 2006 12:04PM

<< Just think with enough heat you could make a nickel into a quarter. >>

And with enough electricity, you can make a quarter into a nickel!

aus3000tin · July 28, 2006 8:49AM

This is a stupid quesion, but...
can you leave your coins in the freezer?

Would this solve the problem of temperature and humidity?

Thanks

cladking · July 28, 2006 11:00AM

<< This is a stupid quesion, but...
can you leave your coins in the freezer?

Would this solve the problem of temperature and humidity?

Thanks >>

I used to keep some cold hard cash but it was more for security than storage. I can
think of no compelling reasons not to except that it is usually not practical. There
might problems with frosting or and with heating/ condensation in a frost free. Be
careful they don't contact the ice (frost) or any of the warmed surfaces and be sure
to bring them back to room temperature gradually. If other people use the freezer it
may be an accident waiting to happen.

Given the recent hot weather, a Question: What does exposure to high temperatures do to coins in alb

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