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 Replies: 11 / Views: 2,978 |
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Valued Member
United States
111 Posts |
I've got several slabbed Lincoln cents that have toned over the years. I've searched and only found people using food vacuum sealers, but what I would like to do is build a vacuum chamber so that I don't have to worry about the plastic crushing the coins and albums. should be easy and cost just as much as a food sealer. just a little extra labor, but that's the fun part. anyone store their coins in a vacuum chamber? I'm curious about the pressure differential within holders. I know they're not totally sealed, but there will be a lag in time it takes for the air to come out of the holder. I wonder if it'll crack (explode). I'm doing this experiment at work with a PCI slab. it may not be sealed like one of my PCGS or NGC slabs. I might have to buy a cheap coin slabbed by PCGS and NGC and give it a try. I know I could hand drill a tiny hole in the slab to evacuate the air, but I'm not thrilled about drilling a hole in a slab! Edited by themetallurgist
10/01/2014 11:06 pm
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Pillar of the Community
Canada
2805 Posts |
A vacuum chamber sounds like a really big hassle, honestly - a food vac-packer is probably your best bet. I doubt the NGC and PCGS slabs are so bendy that the pressure of the plastic wrapping on top of them crushes the coins inside. (and if they are - run away)
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Valued Member
 United States
111 Posts |
Brilliant proof Lincolns are probably the most reactive to oxygen and moisture than any other coin. Not sure if a food sealer would be effective enough to suck the air out of the slab. You would think slabs are protection enough, but they aren't based on toning over time. I also have albums that I wouldn't want crushed.
Edited by themetallurgist
10/02/2014 12:42 am
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Bedrock of the Community
 United States
12817 Posts |
Test it out! Sounds like a fun experiment and I'd love to see pictures of your rig.
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Bedrock of the Community
United States
19942 Posts |
Complete overkill, there is no need to store your coins in a vacuum. The main problem with coins turning in slabs is due to poor storage of the slabs. Also, the TPGs don't "seal" coins in slabs properly - they often use poor handling and end-up sealing in contaminants and fingerprints. I've said for years they should rinse every coin with acetone right before slabbing to remove dust, salvia, body oils, etc. that they introduce during handling.
Lincoln Cent Lover!VERDI-CARE™ INVENTOR https://verdi.care/
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Bedrock of the Community
United States
19942 Posts |
Quote:
I've got several slabbed Lincoln cents that have toned over the years. I also have a lot of slabbed Lincolns. They look exactly the same today as when I stored them. What's my trick? 1) Put slabs into heavy duty ziplocks with a sacrificial penny. 2) Put that bag into another bag which contains a desiccant pack. 3) Put that bag into yet another. 4) Put the whole package into a Tupperware-type container. 5) Store in a near-constant temperature area. |
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Bedrock of the Community
United States
20753 Posts |
Just do as I do. Break the coins out of the Slabs and put in Albums. Then put the Albums in Zip Lock Plastic bags and push out as much air as possible. Been doing this for as long as there have been Zip Lock bags and no problems.
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Valued Member
United States
111 Posts |
thanks for the feedback! for whatever reason I have the need to build it. ... with an acrylic top, should look nice! i'll post pictures when it's done. it'll be a couple months yet.
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Valued Member
United States
93 Posts |
Just wondering, if you had sealed slabs they essentially have atmospheric pressure in side of them. Somewhere around 14.7 psi. If you put them in a vacuum chamber that air would expand, there is a possibility they would actually pop there seals making them ever more suceptible to contaminants.
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Pillar of the Community
Australia
2830 Posts |
Interesting thread !
I don't like slabs, and I don't have any.
But the title of the thread caught my eye, and sparked a memory.
When I was in the Army (long ago), our armouries were "vacuumed" at the end of each day - and I don't mean with a Hoover. Allegedly, there was a benefit in removing all moisture, but the real purpose was security - no matter which point a thief chose to make his entry, the vacuum would be lost, and the alarms set off.
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Bedrock of the Community
United States
17884 Posts |
Quote:
Just wondering, if you had sealed slabs they essentially have atmospheric pressure in side of them. Somewhere around 14.7 psi. If you put them in a vacuum chamber that air would expand, there is a possibility they would actually pop there seals making them ever more susceptible to contaminants. Really depends on how rapidly the outside pressure was dropped. The seal on the slabs is often NOT airtight and if the pressure drops slowly the air inside the slabs will work its way out with no problem. A very rapid decompression might cause the slab to crack at the seal if it can't handle the pressure difference. The downside of the vacuum sealing is that if the air inside the slab does come out during the vacuum sealing, when the standard air pressure is resumed any contaminants in the outside air will be sucked INTO the slab as the inside pressure stabilizes, and then be trapped inside the slab with the coin. |
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Bedrock of the Community
United States
19942 Posts |
Quote:
The downside of the vacuum sealing is that if the air inside the slab does come out during the vacuum sealing, when the standard air pressure is resumed any contaminants in the outside air will be sucked INTO the slab as the inside pressure stabilizes, and then be trapped inside the slab with the coin. Indeed, I've been saying that for years. All vacuums will leak eventually sucking in the surrounding air and contaminants. |
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Replies: 11 / Views: 2,978 |
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Posted 10/02/2014 12:42 am
