Possible Penny Indent

[markn]

A cold shunt was described to me this way.

Sometimes you may have seen your mum or someone rolling pastry with a rolling pin.   Some times the, a scrap piece of pastry was folded onto the rolled pastry and was then itself, rolled.   Now, at a a glance, this tag appeared to have been absorbed into the rolled pastry.   But wait.   Leave the pastry alone for a while and this tag will start to lift slightly.   it has not fully been absorbed into the bulk pastry .   This is the same in the steel metal industry.   I used to work at ALCAN Australian and watch the large aluminium ingots being rolled into long sheets, up to 3 miles long.   On occasions, I would witness a loose bit of aluminium on the sheet before it went through the mill.   Same as the pastry example.

Now when that piece of sheet/blank is stamped or put under some form of mould pressure, it will lift up.   Just as shown in the scans.

That is a cold shunt.

That sounds remarkably like what I described above.  OK now it has a name.  Thanks goldy.

[robbiegal]

A cold shunt was described to me this way.

Sometimes you may have seen your mum or someone rolling pastry with a rolling pin.   Some times the, a scrap piece of pastry was folded onto the rolled pastry and was then itself, rolled.   Now, at a a glance, this tag appeared to have been absorbed into the rolled pastry.   But wait.   Leave the pastry alone for a while and this tag will start to lift slightly.   it has not fully been absorbed into the bulk pastry .   This is the same in the steel metal industry.   I used to work at ALCAN Australian and watch the large aluminium ingots being rolled into long sheets, up to 3 miles long.   On occasions, I would witness a loose bit of aluminium on the sheet before it went through the mill.   Same as the pastry example.

Now when that piece of sheet/blank is stamped or put under some form of mould pressure, it will lift up.   Just as shown in the scans.

That is a cold shunt.

and is that also our fabulous 'planchet peel' that we see today?

[markn]

and is that also our fabulous 'planchet peel' that we see today?

Sometimes, perhaps.  But I think most peels are due to impurities in the metal causing it to bond poorly.

[ausjack]

impurities in the metal causing it to bond poorly

Thanks Mark, that's what I was trying to explain ages ago :good: but couldn't get it thru metal doesn't all mix the same hence all the different tests now being questioned. eg when they say a bullet come from a certain batch they have found out that this isn't true as you can have a box of bullets and the metal will test different..wish I could remember the show I see it on and they told us a similar thing thru different metal things I've done like welding and glassier..very interesting that glass is always a liquid..true, and to see this just look at really old windows and you'll see the glass is thincker on the bottom

[markn]

impurities in the metal causing it to bond poorly

Thanks Mark, that's what I was trying to explain ages ago :good: but couldn't get it thru metal doesn't all mix the same hence all the different tests now being questioned. eg when they say a bullet come from a certain batch they have found out that this isn't true as you can have a box of bullets and the metal will test different..wish I could remember the show I see it on and they told us a similar thing thru different metal things I've done like welding and glassier..very interesting that glass is always a liquid..true, and to see this just look at really old windows and you'll see the glass is thincker on the bottom

We had someone give a talk at coin club a while back about a world wide project researching ancient greek coins.  Basically they are performing x-ray spectography on ancient greek coins and from this they can tell where the silver was mined and most of the time WHEN it was mined.  So, they could test a tetradrachm with a design that dates it to 350BC but tell that the silver was mined 200 years early in Turkey.

[ausjack]

very interesting so the one's doing all the fakes better look out soon if they can get it to work

[Robster]

Great info Markn,  another very cool offshoot of Numismatics.!!