Why are 95% of my mint-sealed sets toned?!?!

Hi All:

First post here. I'm a collector of Ikes and all but one of the nickel ones I've purchased that are slabbed are bright white, and almost all the ones I've seen for sale that are slabbed are white. I have about 40 mint sets or about 80 Ikes in the sets and they are almost all toned (probably at least 95% of them). These were all acquired from various sources over the years. Is the mint packaging inherantly (sp?) bad or my luck just bad? I prefer the white ones over the toned.

Thanks for any replies.

 

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It is likely a mixture of circumstances that caused toning/clouding of coins in original mint packaging...
1) The mint hasn't always used the best materials for storing and protecting coins.
2) The packaging is not always sealed well enough.
3) The coins have been in them many years, and have probably been through many owners with different coin storage techniques, or lack there-of.

Materials, construction of packaging, and environment.

 

Oh, and WELCOME!

 

The bad news is that the mint packaging for '68 to '84 mint sets has a thin inner layer of PVC. The good news is that most coins can still be saved with an acetone bath.

 

Thanks for the replies and the welcome!

Humm... an acetone bath. Details? Is this practice frowned upon? Do you supposed the slabbed coins I have purchased were treated in a similar way, and would a grading service deduct from the grading becaue if it? Or, would a grading service deduct for the toning?

Please forgive me if these are noob questions - I got out of collecting in about 1985 when I joined the service and am just now getting back in.

By the way I did throw in a dozen well used Ikes into my pistol reloading tumbler (along with about 200 spent casings) and they came out shiny as heck. Just not sure I'd throw uncirculated ones in there. Just used the standard crushed corn cob media. Bad idea?

 

Does this mean I should cut up my 1970 small date set?

 

I'm interested to know as well. I have tons of mint sets in those years, if this is the case, I'll be removing them immediately into new storage and then they won't be in OGP

 

If there had been any PVC in the Mint cello, your sets would have had green slime on them many moons ago, paleface.

Chris

 

I avoid talking about US coins in this forum and it's difficult to provide a comprehensive answer without doing so.

US mint packaging material since 1955 earns a solid B+ which is excellent by world standards. Many mints issue their coins in packaging which will simply destroy the coins in a few years. Try finding a nice 1975 Japanese mint set if you don't believe it. Most mints have been making improvements in recent years though and most new packaging should stand up to the long term (I believe).

It appears that the PVC in the '68 to '84 mint sets was used to help bond the outer layers of pliofilm together. It is on both insides of the pliofilm. It is extraordinarily thin. It is so thin that very little "green residue" is generated. Indeed, I've never actually seen the green but it is enough to attact the surfaces. Damage is very negligible at first and soaking it off in acetone (depending on denomination) will probably suffice to saving the coin. But if left on long enough the coin will pass from hazed, to mottled, to very light corrosion, to being destroyed.

For denominations that are best treated with acetone they will need to be left in for 5 minutes to four days dependent on the severity of the problem. I find rinsing in warm water more effective at returning these to pristine condition. Some denominations are best treated with isopropyl (91% only!!) or denatured alcohol. Whatever mixture is used water should be strongly avoided.

Put the still wet coins on a soft absorbant towel and pat dry very carefully. Try your procedure with junk coins first to be sure you are doing it properly. Look for hairlines on the coins with a 20x glass.

 

@Cladking. That's interesting where did you get your info? I'd like to do a bit of my own research as a new collector. Maybe find out about the Canadian mint packages. Thanks.

 

It's mostly just experience.

From very early on it was obvious that what mints do and what they say don't really match. In most cases it's not intentional misdirection as it is that their terminology is different and their right hand doesn't know what the left is doing. If they say their packaging is stable it just means the coins won't go bad in shipment (usually). If they say mint set coins are made just like other coins they just mean that they are struck once by a pair of dies. In actuality these coins have been completely different since 1965.

If you look at a bunch of mint sets you'll occasionally find one that was subjected to a very harsh chemical enviroment. Moth balls can cause this too but it's usually an acidic cause I believe. The four layers of plastic will separate and the inner two will burn green on a pin. If the temperature is kept steady and the humidity fairly low this process is slower. I believe that storing the sets on their sides or under pressure accelerates it.

The Canadian packaging seems a little better generally.

 

Then it's a matter of your personal experience and opinion in regards to a problem. That's totally acceptable and worthy of comment. The post seemed to indicate some form of outside knowledge rather than your own. Thanks for clearing that up.

 

Clad, the problem with the above two quotes is that they are basically contradictory. In the first, you state, as a matter of fact, that the US Mint used PVC (even in extremely thin layers, as you state) to bond plio-film. In the second, you state that this is experiential, and not based on any source. Given that we're discussing packing materials and not merely a grade (or something similarly subjective), experience can't be stated as a source.

If your experience includes researching the specific materials used in the US Mint packaging or, alternately, working for the US Mint contractor who packaged the coins, then that's fine, and it should be stated. However, without a specific source, it's actually just your opinion that the US Mint is lying about its claim that no PVC has ever been used in its packaging process.

All of that said, I'm not entirely convinced that Pliofilm is safer for coins than PVC. After all, Pliofilm replaces the vinyl part of the equation with rubber, but both materials contain chlorine. It's always been my understanding that it is the chlorine part of the PVC that causes acid damage on coins. Wouldn't the same hold true for Pliofilm?

Again, I'm not sure on the overall stability of either material, but it would seem that both would have some level of impact on the stored coins. Maybe the rubber compound of the Pliofilm leeches less than PVC, maybe not.

 

I just have to beg to differ; I believe all real knowledge is experience.

You raise some interesting points but my experience in these areas is much more limited so will refrain from stating opinion.

 

Thanks for the kind words.

I don't really know that it's actually PVC in the inner layers of plastic and this is largely assumption based on the color it burns and that it's a soft plastic. For most dates this hasn't presented a lot of problems yet but it is coming. Copper is especially prone to damage from this and all of one mint mark in the '68 Philly packet and most of the copper in the 84 Denver packet are already destroyed. The former have small carbon spots all over them but coins removed and stabilized are OK.

The big cu/ ni's tend to be prone to toning though most of these actually look better with the toning. The worst date is the '69 followed by the '68 and then the '70. Finding any of the 40% coins without at least some hazing is getting difficult. This hazing on these 80% silver surfaces is more difficu;lt to remove and less successful in my experience than other denominations. You can often get it off completely but not always.

It appears to be getting caused by the interior layers of plastic. While my guess is that it was used to help bond the layers together it is possible there was another purpose such as to help keep the coins from sliding arond inside. I do rarely see coins that have been damaged from sliding around in hard plastic but this is unusual.

 

Very interesting topic and from the answers I would venture to say few of you are chemists. Actually, few people in general are chemists, so I think the numbers are on my side. :smile Although I am a chemist with over 25 yrs experience, the following is only my opinion and may or may not have anything to do with reality.

I think the issue has less to do with the composition of the plastic mint packaging (or philo, or whatever cool commercial name they gave it) and has everthing to do with the construction of the packaging. This plastic these coins are held in is very porous and not air tight, hence air flows in and out at ease. Now look at what surrounds any given mint set - in most cases there's a small paper note describing the set with a message from the mint director, a small cardboard insert and the envelope itself. All paper made from this period is filled with chemicals, especially inorganic acids. Just take a look at any book from the 60's or 70's (or the 80's for that matter), the pages are all yellow and beginning to be brittle. You often hear of people having paper based items treated to neutralize the acid in the paper and stop the degradation. Although I do not know for a fact the paper used by the mint is filled with acid, I would say its highly highly likely that the paper is the same as all other paper products of that era and is filled with acids. Therefore I would content that the discoloration of the coins has much more to do with their environment outside the porous plastic container than with the plastic container itself.

 

Thank-you Cladking, you just save a big chunk of my collection. I recently bought a bunch of 2x2s that had different coloured cardboard instead of the traditional white. I thought they would be great for organizing the AU coins I pull out of circulation. I purchased a roll of each denomination from the post office last year and this year, but still pull the occasional piece out of circulation just to sit on incase I want to piece some sets together later on. Any ways I thought they would help keep things a little better organized in my boxes. The plastic in them didn't smell like pvc but it didn't feel like mylar, so I tried burning a bit and it burned green, so now I'm going to put them back in the standard 2x2s. ]

 

I've taken all of my uncirculated mint sets and put them in a 3 ring binder that fits 4 cello packs to a page, protective pages. I've kept the original envelopes though as I believe it increases the overall value of the sets to have them. I guess I'll find out if what you're saying is true or not, perhaps in the next 5 or more years I'll let you know if I see any considerable damage to my mint sets.