Sealing NGC slabs?

[BAJJERFAN]

Does anyone know if NGC slabs are sonically sealed similar to the PCGS ones?

[MarkFeld]

To my knowledge, yes.

[Deerefan8420]

There's a pretty good video on the NGC website that takes you through an overview of their gradig proxess, which also covers a bit on encapsulating and sonically sealing the slabs. It's a good video if you have 6-7 minutes to spare.

[BAJJERFAN]

Thanks

[mumu]

From what most people say theres not much point to it. Water can get in, air can get in. Toning gases can get in. Only benefit is I guess the coins cant hear anything.

[James_OldeTowne]

From what most people say theres not much point to it. Water can get in, air can get in. Toning gases can get in. Only benefit is I guess the coins cant hear anything.

I believe there's substantial benefit in that the slabs become tamper-evident.

[brg5658]

From what most people say theres not much point to it. Water can get in, air can get in. Toning gases can get in. Only benefit is I guess the coins cant hear anything.

 

The "sonic" part of the sealing has to do with the method by which the two plastic halves are welded together. It has nothing to do with sound's ability to enter the slab. In brief, high frequency sound waves together with high pressure allow the two plastic halves to weld together without the use of glues or much heat.

 

See this article to understand how ultrasonic welding works.

[BAJJERFAN]

But can the energy be transferred to the coin inside the slab?

[mumu]

I will read the article.

[BruceS]

There's a pretty good video on the NGC website that takes you through an overview of their gradig proxess, which also covers a bit on encapsulating and sonically sealing the slabs. It's a good video if you have 6-7 minutes to spare.

 

does anybody have a link to the video?

[Deerefan8420]

http://www.ngccoin.com/coingrading/ngc-coin-certification-overview.aspx

 

That will take you to the Coin Certification Overview page. The video will be at the bottom of the page and should load automatically.

[braddick]

From what most people say theres not much point to it. Water can get in, air can get in. Toning gases can get in. Only benefit is I guess the coins cant hear anything.

 

The "sonic" part of the sealing has to do with the method by which the two plastic halves are welded together. It has nothing to do with sound's ability to enter the slab. In brief, high frequency sound waves together with high pressure allow the two plastic halves to weld together without the use of glues or much heat.

 

See this article to understand how ultrasonic welding works.

 

Yet, if a coin falls out of a slab and there is not an ear to hear it, does it make a sound?

[e1cnr]

But can the energy be transferred to the coin inside the slab?

 

Yes, and it stays stable until exposed to atmosphere, which releases the energy and causes the plastic to explode into many pieces.

[halfpint]

 

...i believe this to be the video referred to.

[BAJJERFAN]

But can the energy be transferred to the coin inside the slab?

 

Yes, and it stays stable until exposed to atmosphere, which releases the energy and causes the plastic to explode into many pieces.

 

I think you miss the point. If you heat a piece of iron to red hot with a torch, the iron begins to cool as soon as you move it away from the torch. I'm not implying that if the ultrasonic energy is transferred to the coin that it moves around inside the slab like a Mexican jumping bean. The coins as received from the Mint are considered "as manufactured" and are likely to have something on them that eventuates in the formation of spots/milk spots. I am wondering if the short term exposure to the extra burst of energy from the sonic sealer might cause the appearance to these spots to be accelerated. The anecdotal evidence seems to suggest that the spots on PCGS holdered ASEs, etc. appear sooner than they do on coins in other TPG holders. If this is true, then there has to be some rational explanation. Perhaps this is due to the frequency at which the sonic sealer/s are being operated. This is merely a SWAG on my part. Do you have a different or better explanation?

[brg5658]

BAJJER it could maybe also have something to do with the different materials insulating the coin from heat between NGC and PCGS holders. The NGC inserts (white part) are a rubber-like inert material and seem (at least from the ones I have cracked out) as though they would be quite insulating from the slight temperature dissipation from the sonic sealing. PCGS holders don't have this insulating material. Just an hypothesis. I need to crack a newer PCGS holder and see that the prongs are made of. Some type of inert flexible translucent rubber-like material I presume?

 

I'm just thinking "out loud" here. I agree with your assessment that PCGS ASEs seem to milk spot at a higher/faster rate than those in NGC plastic.

 

I'm just waiting for that $86K proof ASE to spot

[BAJJERFAN]

BAJJER it could maybe also have something to do with the different materials insulating the coin from heat between NGC and PCGS holders. The NGC inserts (white part) are a rubber-like inert material and seem (at least from the ones I have cracked out) as though they would be quite insulating from the slight temperature dissipation from the sonic sealing. PCGS holders don't have this insulating material. Just an hypothesis. I need to crack a newer PCGS holder and see that the prongs are made of. Some type of inert flexible translucent rubber-like material I presume?

 

I'm just thinking "out loud" here. I agree with your assessment that PCGS ASEs seem to milk spot at a higher/faster rate than those in NGC plastic.

 

I'm just waiting for that $86K proof ASE to spot

 

Not really my assessment about the spotting. That is what I gleaned from posts on the PCGS boards about the subject. I believe that the prongs on the pcgs slabs are made of the same material as the rest of the slab is.

[RWB]

They have a "sonic screwdriver" on loan from Dr. Who.

[brg5658]

BAJJER it could maybe also have something to do with the different materials insulating the coin from heat between NGC and PCGS holders. The NGC inserts (white part) are a rubber-like inert material and seem (at least from the ones I have cracked out) as though they would be quite insulating from the slight temperature dissipation from the sonic sealing. PCGS holders don't have this insulating material. Just an hypothesis. I need to crack a newer PCGS holder and see that the prongs are made of. Some type of inert flexible translucent rubber-like material I presume?

 

I'm just thinking "out loud" here. I agree with your assessment that PCGS ASEs seem to milk spot at a higher/faster rate than those in NGC plastic.

 

I'm just waiting for that $86K proof ASE to spot

 

Not really my assessment about the spotting. That is what I gleaned from posts on the PCGS boards about the subject. I believe that the prongs on the pcgs slabs are made of the same material as the rest of the slab is.

 

If the PCGS prongs are made of a hard brittle plastic like the rest of the slab, how on earth do they "seat" the coins in them without damaging them? The white prongs from NGC holders are quite pliable, and the coins simply pop in. I will definitely try to find a cheap new PCGS pronged holder and crack it open for my own curiosity.

 

-brg

[BAJJERFAN]

BAJJER it could maybe also have something to do with the different materials insulating the coin from heat between NGC and PCGS holders. The NGC inserts (white part) are a rubber-like inert material and seem (at least from the ones I have cracked out) as though they would be quite insulating from the slight temperature dissipation from the sonic sealing. PCGS holders don't have this insulating material. Just an hypothesis. I need to crack a newer PCGS holder and see that the prongs are made of. Some type of inert flexible translucent rubber-like material I presume?

 

I'm just thinking "out loud" here. I agree with your assessment that PCGS ASEs seem to milk spot at a higher/faster rate than those in NGC plastic.

 

I'm just waiting for that $86K proof ASE to spot

 

Not really my assessment about the spotting. That is what I gleaned from posts on the PCGS boards about the subject. I believe that the prongs on the pcgs slabs are made of the same material as the rest of the slab is.

 

If the PCGS prongs are made of a hard brittle plastic like the rest of the slab, how on earth do they "seat" the coins in them without damaging them? The white prongs from NGC holders are quite pliable, and the coins simply pop in. I will definitely try to find a cheap new PCGS pronged holder and crack it open for my own curiosity.

 

-brg

 

If you look at a PCGS slab it's easy enough to see how the 2 identical halves fit together sandwiching the coin in between. I'd guess it is a snug fit. Frankly, I don't have any new NGC slabbed coins so I can't say anything about them. Are you sure that the whole insert isn't pliable? Doesn't seem to me that they'd use 2 different materials.

[brg5658]

BAJJER it could maybe also have something to do with the different materials insulating the coin from heat between NGC and PCGS holders. The NGC inserts (white part) are a rubber-like inert material and seem (at least from the ones I have cracked out) as though they would be quite insulating from the slight temperature dissipation from the sonic sealing. PCGS holders don't have this insulating material. Just an hypothesis. I need to crack a newer PCGS holder and see that the prongs are made of. Some type of inert flexible translucent rubber-like material I presume?

 

I'm just thinking "out loud" here. I agree with your assessment that PCGS ASEs seem to milk spot at a higher/faster rate than those in NGC plastic.

 

I'm just waiting for that $86K proof ASE to spot

 

Not really my assessment about the spotting. That is what I gleaned from posts on the PCGS boards about the subject. I believe that the prongs on the pcgs slabs are made of the same material as the rest of the slab is.

 

If the PCGS prongs are made of a hard brittle plastic like the rest of the slab, how on earth do they "seat" the coins in them without damaging them? The white prongs from NGC holders are quite pliable, and the coins simply pop in. I will definitely try to find a cheap new PCGS pronged holder and crack it open for my own curiosity.

 

-brg

 

If you look at a PCGS slab it's easy enough to see how the 2 identical halves fit together sandwiching the coin in between. I'd guess it is a snug fit. Frankly, I don't have any new NGC slabbed coins so I can't say anything about them. Are you sure that the whole insert isn't pliable? Doesn't seem to me that they'd use 2 different materials.

 

The NGC core (the white part inside the clear harder plastic) is all pliable. It's made of what I would describe as a "rubber-like" material. I never said they used two different materials on the core of NGC holders.

 

PCGS holders are different though. They don't really have a "core". There are two halves of the hard plastic shell that fit together, but I always just assumed the part with prongs around the coin was a pliable material that the coin was put into before it was sealed between the two shells.

[BAJJERFAN]

 

 

 

 

BAJJER it could maybe also have something to do with the different materials insulating the coin from heat between NGC and PCGS holders. The NGC inserts (white part) are a rubber-like inert material and seem (at least from the ones I have cracked out) as though they would be quite insulating from the slight temperature dissipation from the sonic sealing. PCGS holders don't have this insulating material. Just an hypothesis. I need to crack a newer PCGS holder and see that the prongs are made of. Some type of inert flexible translucent rubber-like material I presume?

 

I'm just thinking "out loud" here. I agree with your assessment that PCGS ASEs seem to milk spot at a higher/faster rate than those in NGC plastic.

 

I'm just waiting for that $86K proof ASE to spot

 

Not really my assessment about the spotting. That is what I gleaned from posts on the PCGS boards about the subject. I believe that the prongs on the pcgs slabs are made of the same material as the rest of the slab is.

 

If the PCGS prongs are made of a hard brittle plastic like the rest of the slab, how on earth do they "seat" the coins in them without damaging them? The white prongs from NGC holders are quite pliable, and the coins simply pop in. I will definitely try to find a cheap new PCGS pronged holder and crack it open for my own curiosity.

 

-brg

 

If you look at a PCGS slab it's easy enough to see how the 2 identical halves fit together sandwiching the coin in between. I'd guess it is a snug fit. Frankly, I don't have any new NGC slabbed coins so I can't say anything about them. Are you sure that the whole insert isn't pliable? Doesn't seem to me that they'd use 2 different materials.

 

The NGC core (the white part inside the clear harder plastic) is all pliable. It's made of what I would describe as a "rubber-like" material. I never said they used two different materials on the core of NGC holders.

 

PCGS holders are different though. They don't really have a "core". There are two halves of the hard plastic shell that fit together, but I always just assumed the part with prongs around the coin was a pliable material that the coin was put into before it was sealed between the two shells.

 

I misunderstood your comment about the NGC inserts then. I always tought the white insert was teflon, though that would be pricey. It's probably a polyurethane of some sort. The PCGS prong/ed slabs have no insert/gasket, etc. A friction fit likely holds the coin in place. I could be wrong but the clear part of an NGC slab is a different material than PCGS uses. The sonic sealing requirements may be different too.

[Crohnos01]

From a purely practical standpoint, I would doubt the ultrasonic transmissions would have any adverse impact on the coin in the slab. As the article mentions, the pressure and heat from the process extends only a millimeter or so into the material to be welded. There is too much distance and open air space between the coin and the transmission source in my estimation for any part of the process to affect the spotting of the coins. I would be more likely to examine the materials inside the slab for off gassing and how those compounds might react with the residual wash on the coin from the mint.

[BAJJERFAN]

From a purely practical standpoint, I would doubt the ultrasonic transmissions would have any adverse impact on the coin in the slab. As the article mentions, the pressure and heat from the process extends only a millimeter or so into the material to be welded. There is too much distance and open air space between the coin and the transmission source in my estimation for any part of the process to affect the spotting of the coins. I would be more likely to examine the materials inside the slab for off gassing and how those compounds might react with the residual wash on the coin from the mint.

 

The material which causes the spots is already on the coin before it gets put into an NGC or PCGS holder. Others have stated that ASEs in PCGS slabs seem to have the spots become visible sooner than for ASEs in NGC slabs. I do not know if this is true or not, only what others say. For PCGS, the coin is in contact with the slab. For NGC the coin is in a pliable insert and is pretty well insulated from the edge of the holder. Seems reasonable to me that a small amount of vibration could be transferred to a coin in a PCGS slab, but not so much in an NGC slab. It would be easy enough to test by sealing 20 ASEs in PCGS slabs and putting another 20 from the same monster box and not sealing them. Store both under the same conditions and see which lot starts to spot first.

 

As I said, it's puerly speculation on my part.

 

 

[bochiman]

There is a small, pliable, gasket in the PCGS holder as well.

I have cracked a few out and have them.

 

I have NOT cracked one out of a NGC holder to compare the 2 though. I don't have any SAEs in NGC.

[BAJJERFAN]

There is a small, pliable, gasket in the PCGS holder as well.

I have cracked a few out and have them.

 

I have NOT cracked one out of a NGC holder to compare the 2 though. I don't have any SAEs in NGC.

 

Might be in the older PCGS, but the newer ones don't have one. The comments about faster spot appearance seem to be for more recently holdered coins, say the last couple of years. I have some older PCGS spotted coins to crack out so we'll see.

[Crohnos01]

From a purely practical standpoint, I would doubt the ultrasonic transmissions would have any adverse impact on the coin in the slab. As the article mentions, the pressure and heat from the process extends only a millimeter or so into the material to be welded. There is too much distance and open air space between the coin and the transmission source in my estimation for any part of the process to affect the spotting of the coins. I would be more likely to examine the materials inside the slab for off gassing and how those compounds might react with the residual wash on the coin from the mint.

 

The material which causes the spots is already on the coin before it gets put into an NGC or PCGS holder. Others have stated that ASEs in PCGS slabs seem to have the spots become visible sooner than for ASEs in NGC slabs. I do not know if this is true or not, only what others say. For PCGS, the coin is in contact with the slab. For NGC the coin is in a pliable insert and is pretty well insulated from the edge of the holder. Seems reasonable to me that a small amount of vibration could be transferred to a coin in a PCGS slab, but not so much in an NGC slab. It would be easy enough to test by sealing 20 ASEs in PCGS slabs and putting another 20 from the same monster box and not sealing them. Store both under the same conditions and see which lot starts to spot first.

 

As I said, it's puerly speculation on my part.

 

 

I think we are saying the same thing differently. Yes, the substance causing the spots is on the coins before encapsulation. I just think it is more likely that once the slab is sealed, the materials inside the slab offgass some compound that reacts with the substance on the coins rather than the sonic welding operation itself causing the spotting.