Question About Slabs

[Bennett]

Let's assume for the sake of argument that TPG slabs are completely airtite. If so, what effect does the air inside the slab have on the coin. After all. there's a pocket of air between the coin and the plastic that doesn't circulate out at all. Is the answer that the impurities in that inside air do their thing on the coin and then stop once they're used up? Is the inside air inert at that point, and therefore much safer on the coin than outside air?

 

Another related point: seems to me that 2x2s are the only coin storage medium with little or no "inside air" element. Is that an advantage of a 2x2 over a slab (or an airtite, which also has a pocket of inside air)?

[MunkyMan95]

But, I don't think the slabs are airtight. They need to breathe. The coins need to breathe.

 

I do know, however, that ICG slabs are water-tight. Don't ask.

[MarkFeld]

Slabs are not airtight, so don't assume that they are. If a coin has started to oxidize/react before being holdered, it can continue to do so after being sealed. And even if it hasn't started to oxidize first, gases can permeate the plastic and cause a reaction, anyway.

[PerryHall]

As pointed out by others, slabs are not air tight. When the barometric pressure changes, air will either enter or leave a slab. Higher external barometric pressure means air enters the slab. Lower external barometric pressure means air leaves the slab.

[cpm9ball]

I do know, however, that ICG slabs are water-tight. Don't ask.

 

He couldn't find his rubber ducky when it was time for his bath.

 

Chris

[RGT]

I do know, however, that ICG slabs are water-tight. Don't ask.

 

He couldn't find his rubber ducky when it was time for his bath.

 

Chris

 

I assume that when he said "don't ask" he also meant "don't tell".

[Conder101]

The OP started with the statement

Let's assume for the sake of argument that TPG slabs are completely airtite.

So we are not dealing with a real world scenario, we are answering a hypothetical question.

 

Is the answer that the impurities in that inside air do their thing on the coin and then stop once they're used up? Is the inside air inert at that point, and therefore much safer on the coin than outside air?

Correct, toning is a chemical reaction and with any chemical reaction one of the reactants acts as the limiting agent and once that reactant has been consumed the chemical reaction stops. If the slab was completely airtight no more reactant could get in and no more toning would take place.

 

But as the others have said this is not the case in the real world, and reactants would continue to slowly migrate their way into the holder so the reactions would continue, but since it would be difficult for them to get inside the toning will take place much more lowly than if it was outside the holder.

[Jeff S]

Slabs are not bullet proof either.

Ask my Sig .40

[Oldtrader3]

I remember back before it nearly killed me that I used to smoke (nasty habit). I had some early slabs where the coins turned yellowish from being exposed to cigarette smoke. This was before I kept my coins in a moisture controlled safe.

[Coin]

There are commercial 'airtite' containers that could possibly hold your slabs , but each time you open or close the case and break the seal...you are re-starting the process....you aren't thinking about making a time capsule or something are you?

 

You can do a search on some of the 'survivalist' web sites that cater to the folks that think all will end and they need to store anything useful....and find some of these containers . When I was in the military , we sometimes had to pull equipment from similar containers by pressing purge valves to let in air and release any trapped gases to equalize the inside pressure prior to opening the container to retrieve the devices . I've seen stuff like that available in the free market.

 

*edit*

I'm talking about environmental resistant boxes and containers to put the slabs in , not slabs .

[BankNote1]

I like to buy coins in the older slabs not just because the coin might be undergraded but hopefully the coin has changed all it is going to.

[Houston Investor]

Slabbed coins have a certain "shelf life" and then the ravages of oxidation, humidity, cigarette smoke, and heat eventually take their toll. If this toning is attractive, you may even be able to sell your coins at a premium. But a lot of the time it can get really ugly. As pointed out by others, the slabs are not airtight and many collectors do not store their coins in the optimum environment. Then they blame the TPG's because the coin "went bad."