Topic: Intercept shield

[mrslick32]

Badon and Poconopenn, I have a question for both of you since you both have backgrounds in Chemistry. What do you think of the Intercept Shield products? Do you think they are effective in helping prevent the tarnishing and spotting of coins? Thanks for sharing your expertise with everyone.

[Underbidder]

I personally think the Intercept Shields are effective in preventing the diminishing of the bank accounts of those who sell them.

[badon]

Badon and Poconopenn, I have a question for both of you since you both have backgrounds in Chemistry. What do you think of the Intercept Shield products? Do you think they are effective in helping prevent the tarnishing and spotting of coins? Thanks for sharing your expertise with everyone.

I took a look at their website, and although the principle is sound, the way they're using it doesn't seem like it would work for very long. I could not find any details of how they claim that it's supposed to work, so I dismissed it as a sham.

But, it might not be - it depends on how well it seals. Either way, I think you can do the same thing much cheaper by just using cheap uline bags.

These are the ones I use for normal sized slabs:

http://www.uline.com/Product/Detail/S-11579/High-Clarity-Polypropylene-Bags/3-x-4-2-Mil-Reclosable-Polypropylene-Bags?FromOrderHistory=Y

These are the ones I use for large size slabs, like for the god of longevity, war & wealth, 5 oz coins, etc:

http://www.uline.com/Product/Detail/S-10644/High-Clarity-Polypropylene-Bags/7-x-9-2-Mil-Reclosable-Polypropylene-Bags?FromOrderHistory=Y

These fit nicely over most coin capsules:

http://www.uline.com/Product/Detail/S-13263/High-Clarity-Polypropylene-Bags/2-x-3-2-Mil-Reclosable-Polypropylene-Bags?FromOrderHistory=Y

I use these cheaper versions for temporary sealing when shipping coins to NGC, or if I want to double (or triple!) seal a coin:

http://www.uline.com/BL_208/2-Mil-Reclosable-Bags

The high clarity polypropylene bags are ESSENTIAL for storage, display, and enjoyment of your slabbed coins. They keep fingerprints, dust, dirt, and scratches off of your coins. I never worry when I hand a coin to someone, and I'm not sure if they've still got some lunch on their hands :)

However, you have to make sure you blast the dust off of the slabs before you put them in the bags. If you don't, the dust will scuff them up inside the bags.

To blast the dust off, you'll need this if you have strong hands, but don't want to spend much:

http://www.amazon.com/Giottos-AA1900-Rocket-Blaster-Large/dp/B00017LSPI/ref=pd_cp_p_0

If you're doing a lot of slabs, this is a great investment:

http://www.amazon.com/gp/product/B001J4ZOAW

But, it's loud enough that it WILL damage your hearing after a few uses, guaranteed, so get some earplugs:

http://www.amazon.com/gp/product/B001EPQ3H4

[poconopenn]

Yes, Intercept Shield products, using the technology developed by Bell Labs, will do the job to intercepts the corrosive gases in the air which can tarnish or corrode a valuable coin. However, I do believe that double sealed package is good enough.

[mrslick32]

Thank you Badon and Poconopenn for your feedback. I really appreciate it.

[badon]

It seems that poconopenn and I agree :)

[badon]

I split this discussion from here:

http://china-mint.info/forum/index.php?topic=3621.msg17290#msg17290

[Underbidder]

The Interceptor Shields I have are not sealed- it seems air can get in them.  So then is it depending on the chemical inside, to continually attract and trap oxidizers in the air, without EVER getting depleted or worn out?  Please X'plane dat to my admittedly non PhD mind.
I think I'd sooner trust a vacuum sealed baggie.

[badon]

That was the exact same conclusion I came to. Even though in principle it may actually work, but if it isn't sealed, it'll "wear out" within a short time as the neutralizing chemicals are consumed, and eventually completely depleted.

[mrslick32]

I have a few Intercept Shield boxes and I asked the question before I buy more. Underbidder is correct that they are not airtight. However, based on what I read on their website and Poconopenn's feedback that the technology is sound, I think it will do its job. However, I think that it's best to do my own double sealing (or triple seal because my coins are slabbed) so I will also buy the archival safe polybags where I will put my slabs to double seal the coin. Then I will put the polybags on the Intercept Shield boxes since I need to store them anyway.

I couldn't have come to that conclusion if not for the feedback I received here so thank you everyone.   In case anyone is interested to know, I did some research for the polybags after reading Badon's feedback about Uline. I think it's a good brand but I thought it was quite expensive and I don't need 1,000 bags so I looked around and found GT Zip. I believe that they are the suppliers of the Ziplock brand bags sold in grocery stores and they have an archival safe product line called "Ultra Clear". The Ultra Clear bags are cheaper than Uline and you have an option to buy 100 pieces if you buy their "Lip and Tape" bags. I haven't made any purchase yet since I'm still looking around but I thought about sharing it with all of you in case anyone is interested.

Here's the link to the Lip and Tape bags:
http://www.gtzip.com/polypro/lipandtape.html

They also have the regular 2 Mil poly bags:
http://www.gtzip.com/ziplock/ucplain2mil.html

This is their explanation for the different types of poly bags:
http://www.gtzip.com/archival.html

[Underbidder]

Yeah, so back to your baggie. And a quick kiss to the corner to suck the air out--

[badon]

Don't get the lip and tape bags. They aren't at all sealed, and they tend to leave sticky goo on your slab when you take it out or put it in.

The ultra clear bags do look to be about half the price of the uline though, thanks for the link. I might buy some to see if they are as good as the uline.

[mrslick32]

Thanks for the feedback regarding the Lip and Tape bags.

[comeaux]

Hi badon ... for long term storage i have my slabs stored in NGC boxes which are in bank safety deposit boxes, should I take the slabs out of these NGC boxes and put the slabs in these bags you referenced for safer lomgterm (years) storage.
thanks in advance !

[poconopenn]

The intercept shield products are made with flexible plastic impregnated with copper in the atom state which can neutralizes the sulfur gases before these gases can react with coins. The toning is caused by reaction between sulfur gases and silver and copper atom on the surface of the coin. The intercept shield, according to study conduct by Weimar White, a well-known numismatist and specilized in coin chemistry,  should be good for five years.

For bags mentioned by Badon, I will storngly recommend that a freshly minted copper penny be placed inside the bag to give extra protection. The copper penny should be replaced when it shows sign of toning.

Bank safety deposit box is a perfect place to store coins. Usually, it is enviromental control and should be good enough without extra protection. This is the place I store my valuable coins.    

[badon]

Comeaux, poconopenn's advice is pretty good. 

[fractalfate]

So what size baggies for the longer NGC 5-coin multiholder slabs and the the giant kilo slabs? Thanks.

[mrslick32]

So what size baggies for the longer NGC 5-coin multiholder slabs and the the giant kilo slabs? Thanks.

For the kilo slab you may use the 7X9 poly bag. I have some for sale that I offered on the thread I posted below. I am not sure about the 5-coin multiholder. If the holder is the same size as the oversize holder for coins over 45mm in diameter then it will fit in the 7X9 poly bag.

http://china-mint.info/forum/index.php?topic=3724.msg18224;topicseen#msg18224

[KeepOnTrying!]

Given the cost of coins and medals we collect I believe it is right to continue exploring ways to preserve their integrity for years to come. I have recently packaged some coin slabs using a combination of intercept bags and vacuum sealing. There are proponents for each type of preservation process. I thought maybe I could utilize the presumed benefits of both methods. Whether this works at all or works better than other approaches including leaving in OMP can only be determined with time.

I placed each coin slab in an intercept bag but did not close the clasp of the bag. I then placed six such coin slab/intercept bag sets in a “food safe” vacuum bag followed by vacuum sealing.

Below is attached a photo of the assembled sets before sealing.

[KeepOnTrying!]

The attached image shows the slab/intercept bag/“food safe” vacuum bag setup following vacuum sealing. The vacuum sealing also answered my need for moisture protection when storing slabs. Prior to this I would normally place the slab in an intercept bag followed by double bagging with added desiccant sachets because both home and bank safes do not guarantee zero humidity.

Again, this is just an empirical endeavor but waiting for 5-20 years to find out who is right may not help the fence sitter. This is not necessarily an original thought; there may be others who have already used this “double” protection approach. I initially placed slabs in a plastic coin slab protector followed by vacuum sealing in a food safe bag and then placement in a large intercept bag.

Yes I know; the people who made money during the Californian gold rush (and others before and afterwards) were those who sold the shovels, pans and other supplies needed by the prospectors!

[NBM]

I placed each coin slab in an intercept bag but did not close the clasp of the bag.

Why not seal the intercept bag?

[KeepOnTrying!]

Why not seal the intercept bag?

I left it open so that the air that is inside each Intercept bag and around each slab is vacuumed out. The sealed food safe bag maintains the seal for all the intercept bags so to speak.

[NBM]

I see, thank you.

[Mirkkanen]

I left it open so that the air that is inside each Intercept bag and around each slab is vacuumed out. The sealed food safe bag maintains the seal for all the intercept bags so to speak.

Your use of the bag in bag WILL NOT ACHIEVE THE DESIRED OUTCOME.

According to my understanding of intercept bags, they MUST BE CLOSED/SEALED in order to be effective. They NEUTRALIZE harmful gasses enclosed WITHIN the seal and PREVENT harmful gasses outside of the bag from ENTERING.

If you have left the Intercept shield bags OPEN, then you have rendered BOTH Intercept benefits INEFFECTIVE.

As Chris will likely explain, the vaccuum seal bag does not perform either function of the Intercept bag and serves NO PURPOSE for coin preservation.

[KeepOnTrying!]

Your use of the bag in bag WILL NOT ACHIEVE THE DESIRED OUTCOME.

According to my understanding of intercept bags, they MUST BE CLOSED/SEALED in order to be effective. They NEUTRALIZE harmful gasses enclosed WITHIN the seal and PREVENT harmful gasses outside of the bag from ENTERING.

If you have left the Intercept shield bags OPEN, then you have rendered BOTH Intercept benefits INEFFECTIVE.

As Chris will likely explain, the vaccuum seal bag does not perform either function of the Intercept bag and serves NO PURPOSE for coin preservation.

I have to stress that what I have described is not how the manufacturer of the Intercept bags has recommended for the bags to be used. Therefore failure of the "experiment" to produce results that are similar to those claimed for the ideal use of Intercept bags cannot in this instance be blamed on the said Intercept bags.

Vacuum sealing of the whole assembly as I described above has the net effect of removing most of the air between the bags and the coin slabs and between individual bag/slab components and the food safe bag. At the end of the air withdrawal process the two leaves of the Intercept bags above each slab are closely and tightly apposed to each other to the point of providing a virtual seal of each bag.

But that is not the main closure mechanism in my set up; heat sealing of the food safe bag provides an additional barrier to air entry into the vacuumed space. I do not have any data regarding the coefficient of diffusion of air and toxins across the plastic material of the Intercept bag compared to that of the food safe bag. I don’t know which is a better barrier. But virtually all plastic sheets are somewhat permeable to the diffusion of gases.

Equally important to me is that vacuum sealing these bags and slabs like I have done protects them from ambient water vapor in addition to accidental water immersion. Furthermore, a plastic bag with a sealing clasp may be waterproof (or water retardant) but cannot guarantee 100% exclusion of water from the contents in cases of total water immersion compared to the vacuum sealed food safe bag set up I described.

[jc888888888]

 I once had a big part of my collection Vacuum sealed and stored in the bank vault............  but the problem was I kept opening them to look at them when I went there  :) part of the enjoyment of collecting for me ... is to almost forget you had a certain coin and then come across it again ....like an old friend coming for a visit you get to enjoy it again.

[1668Chris]

Your use of the bag in bag WILL NOT ACHIEVE THE DESIRED OUTCOME.

According to my understanding of intercept bags, they MUST BE CLOSED/SEALED in order to be effective. They NEUTRALIZE harmful gasses enclosed WITHIN the seal and PREVENT harmful gasses outside of the bag from ENTERING.

If you have left the Intercept shield bags OPEN, then you have rendered BOTH Intercept benefits INEFFECTIVE.

As Chris will likely explain, the vaccuum seal bag does not perform either function of the Intercept bag and serves NO PURPOSE for coin preservation.

This is correct and explained on my site

[1668Chris]

But that is not the main closure mechanism in my set up; heat sealing of the food safe bag provides an additional barrier to air entry into the vacuumed space. I do not have any data regarding the coefficient of diffusion of air and toxins across the plastic material of the Intercept bag compared to that of the food safe bag. I don’t know which is a better barrier. But virtually all plastic sheets are somewhat permeable to the diffusion of gases.

This data is also available on our site in an easy to read chart.

[KeepOnTrying!]

This data is also available on our site in an easy to read chart.

Do the two leaves of the Intercept bag (i.e. the clear transparent leaf and the brownish translucent leaf) both contain the Intercept material/matrix?

[KeepOnTrying!]

I once had a big part of my collection Vacuum sealed and stored in the bank vault............  but the problem was I kept opening them to look at them when I went there  :) part of the enjoyment of collecting for me ... is to almost forget you had a certain coin and then come across it again ....like an old friend coming for a visit you get to enjoy it again.

You can cut below the heat sealed line to liberate the slabs and repeat the vacuum sealing when you are done, as long as you have enough of the sheet above the coin slabs to allow this. It is usually advised when initially cutting out the length of bag you need for your slabs that you should leave several inches/centimeters of the plastic sheet to allow you reseal the bag up to 3-4 times.

[Stark]

I put all coins and medals that meant something more to me into 2 Intercept bags and in additional bag for food that is vacuum sealed. In the beginning I was doing vice versa I think, so first vacuum seal and then in the Intercept bags.

In the very beginning I just vacuum sealed coin with box if it was not too big.

I noticed recently after some time of storing (without Intercept bags) that one coin started to get toning. I assume that coin capsule had a small crack somewhere.

I will maybe do some experiments in the future.