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Author Topic: Transfer die faking process - explain?  (Read 1261 times)

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Offline Ron C2

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Transfer die faking process - explain?
« on: June 28, 2021, 09:22:40 am »
I checked numiswiki and Google. Precious little is out there actually describing the transfer die process.

Basically what I found is that a real coin is used to make a negative on a steel die set and then those dies strike real coins.

But what is the actual process to make the negative on a new striking die?

I'm not looking for enough detail to actually do this, just enough of an explanation so I can visualize it and possibly be better at detecting such fakes.

Anyone able to elaborate in layman's terms? 

I apologize if it is already available on forum. I looked and didn't find it.
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Offline Din X

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Re: Transfer die faking process - explain?
« Reply #1 on: June 28, 2021, 11:03:05 am »
You can produce transfer dies by electroplating and casting.
If the dies are casted the process is most likely identical or similar as if you cast a coin.
I will explain a little bit how to do by electroplating.

But the first step is always the same you need to get an imprint of an authentic or fake coin from which you want to produce the dies.
For this they generally use silicon rubbers like this one.

https://www.smooth-on.com/product-line/oomoo/

If you have the imprint you can change/recut details and remove fat from imprint and then making this imprint electric conducive by adding graphite with a  pencil.

Then you connect the imprint to cathode and on anode will be copper (or the copper can be in the liquid solution).

Here electrolating is described

https://www.metmuseum.org/metmedia/video/collections/esda/electrotyping-process

Here electroplating machine (examples google search will show many)

https://www.banggood.com/110V-220V-1510-Goldsmith-Tools-Jewelry-Plating-Machine-Mini-Gold-Plating-Machine-Electroplating-Rectifier-Machine-For-Ring-Necklace-Machine-p-1815041.html?utm_source=googleshopping&utm_medium=cpc_organic&gmcCountry=DE&utm_content=minha&utm_campaign=minha-de-en-pc&currency=EUR&cur_warehouse=CN&createTmp=1&ID=47757&utm_source=googleshopping&utm_medium=cpc_bgs&utm_content=sxxx&utm_campaign=sxxx-ssc-de-css-all-newcustom-ncv90-0623&ad_id=443949120684&gclid=EAIaIQobChMIm5mZjMy68QIVYIODBx2TXgg8EAkYDSABEgIdZ_D_BwE

https://www.real-gold.de/produkte/chrom-verchromen/31/chrom-galvanikanlage?c=10

Then you have a thin copper layer if you go on like this you will produce an electroplated copy of the mother like Rober Ready (British Museum) did, and later this electrotype will be glude together with the other side and then  plated again with Silver or Gold as the authentic mother.
The secret is how to do good electroplating and how to get from negative imprint to negative die and not to positive electrotype coin (you will get one side of the coin, you need 2 imprints for both sides of the mother).
The Copper transfer dies will be later plated with Nickel, because Nickel is not corroding as much as Copper and Nickel is much harder and so Nickel dies are lasting much longer than Copper dies.
And I think Nickel is sticking much better on Copper than on silicon imprint with graphite.





Offline Ron C2

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Re: Transfer die faking process - explain?
« Reply #2 on: June 28, 2021, 12:03:56 pm »
I see, so basically you are making a nickel and copper "shell" that is the shape of the original striking die.  Presumably you then have to either make the back of the shell smooth by either sanding it flat or filling it with something hard like lead or epoxy, then glue it (or solder) to a steel striking punch and then use it to strike a few coins until the transfer die fails or you produce more coins than you can sell without being caught. 

That makes sense for gold coins, but I wonder how these dies hold up to silver or bronze?  Silver, copper, brass and bronze are all around a 3 on the Mohs hardness scale and nickel is only a 4.  Mild steel is 4.5, but quenched and hardened steel is higher still.  I'm guessing a very hot flan would help

Even with heat, I would imaging you would not get very many strikes out of a nickel and copper die is striking silver or a copper alloy.  I wonder how many fakes they can get from this process before a transfer die wears or breaks?  Presumably not that many.
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Offline Din X

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Re: Transfer die faking process - explain?
« Reply #3 on: June 28, 2021, 12:34:44 pm »
I think if you press instead of stike you can control the pressure better and so the dies will last longer and the print of the dies will be transferred pretty well from the dies on the planchet.
If you strike cold the metal is harder and less elastic and you need more strikes and more strikes means you can mint less coins at the end with this dies than with hot striking, where you need less strikes to mint one coin.
It seems like many ancient coins were struck with Bronze dies and not so many with Iron dies (we can see on some coins die rust from corroded iron dies see for example Syracuse).
I have broken Bronze, Nickel and Iron dies.
And I know that from some of the Iron dies not so many fakes were struck (I assume much less than 100) before they broke.
And it depends on Silver alloy there are harder and softer ones.

For different methods how to produce dies you can read

Numismatic Forgery by Charles Larson

https://www.forumancientcoins.com/board/index.php?topic=11216.0

https://www.amazon.de/Numismatic-Forgery-Charles-M-Larson/dp/0974237124

I have this book and do not like it really much, there was nothing new written in it and I did not understand all (my English is not the best)

And for minting practice I recommend

D. G. Sellwood, “Some experiments in Greek minting technique,” NC (1963)

I really liked it and it is available for free and legal online, if you click on pink "Sellwood – Greek Minting 1963 NC" it will download pdf

http://community.vcoins.com/experiments-greek-minting-technique/

Picture some of my Silver planchets given to me by a replica maker with correct alloy.
Planchets are pure Silver impurites can make the Silver harder.



Offline Joe Sermarini

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Re: Transfer die faking process - explain?
« Reply #4 on: June 28, 2021, 03:11:30 pm »
Apparently, ancient counterfeiters made transfer dies by smashing a coin into heated bronze with an extremely hard blow. In Numismatic Forgery, Larson describes a modern forger using a shotgun blast. The coin is destroyed. That is why ancient counterfeits and imitatives that are made with transfer dies almost always have a mismatched obverse and reverse. It destroyed two coins to make the two dies.   

Of course this is NOT how modern fake transfer dies of expensive types have been made.   
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Offline Din X

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Re: Transfer die faking process - explain?
« Reply #5 on: June 28, 2021, 03:29:04 pm »
Nowadays most transfer dies are made by casting if you can cast coins you can cast transfer dies, too.
And the more skilled forgers will produce them by electroplating for better and sharper details.
I have many transfer dies but they are either made by electroplation or casting.
To creat dies " by explosive impact copying" is imho only theory and never done in practice you destroy the coin and to get a shotgun legally is on most countries not possible and to shoot the coin with the right power into the metal should be difficult and dangerous too I assume to get some practice many coins would be destroyed and some forgery hurt and even with practice you hardly can control the result and I doubt the result will be close as good as electroplating.
Instead of using a shotgun you can heat an empty iron die to make it softer and more elastic and then you put the coin on the empty die and mount it that it can not move and then you hammer the details from the coin in the dies and later you will heat the iron die to harden it.
With a hammer or vice or hydraulic press you can control the power better and you do not need a shotgun.
Larson desribes 3 ways how  transfer dies can be created/produced electroplating, casting and explosive impact copying.
And for modern dies hand cutting them or hubbing.


Offline SC

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    • A Handbook of Late Roman Bronze Coin Types 324-395.
Re: Transfer die faking process - explain?
« Reply #6 on: June 28, 2021, 05:15:36 pm »
Larson must be an old book.  The last 99.99% nickel Canadian Nickel was 1981, they were 25% nickel till around the early 2000s and are now mostly steel.

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Offline Din X

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Re: Transfer die faking process - explain?
« Reply #7 on: June 28, 2021, 05:55:08 pm »
The book of Larson is from 2004, I think this is the first and only edition available.
Of course it is well possible that some information in the book were already outdate when they were published.

There is another book on this topic and here is only mentioned for producing transfer dies electroplating and casting (there are only two pages in Sayles book and I uploaded the pictures of tis 2 pages in this post).

Classical Deception: Counterfeits, Forgeries, and Reproductions by Wayne G. Sayles
It was printed 2001 and , I think this is the first and only edition available

https://www.amazon.de/Classical-Deception-Counterfeits-Forgeries-Reproductions/dp/0873419685

Joe Sermarini "Apparently, ancient counterfeiters made transfer dies by smashing a coin into heated bronze with an extremely hard blow"

This is completely new to me where is this information from?

Here Sayles mentiones that forgers have already created transfer dies by casting process in ancient times and this is perfectly true and important because most "ancient dies" on the market are ancinet transfer dies from forgers and not official dies.
This dies show ghost lines showing the planchet end of the mother and parts of dotted border are missing because on many emissions the dies were huger than the planchets and so on most of this coins parts of the dotted border are missing due to "bad" centering meaning this dots were off flan when the coin was struck. And sometimes we can find struck ancient transfer die fakes, struck with such transfer dies in ancient times in auctions, too.
If they could cast transfer dies in ancient times we can guess that we do not need a

Offline Joe Sermarini

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Re: Transfer die faking process - explain?
« Reply #8 on: June 28, 2021, 10:15:40 pm »
Most ancient forgeries were NOT made with transfer dies they were made with hand engraved dies. Most of what I believe were transfer die counterfeits are of Roman Republic denarii.

The information on how ancients made their transfer dies is from personal observation. I used my time machine and watched them do it.  OK, no. We have no certainty of how the dies were made. And every forger would have had their own system. I am very confident, that whatever method they used, it destroyed the coins. Transfer die counterfeits almost always combine the wrong obverse and reverse. If the coins were not destroyed, it seems very unlikely they would have this issue.
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Offline Kevin D

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Re: Transfer die faking process - explain?
« Reply #9 on: June 28, 2021, 11:30:26 pm »
'Dies, Hubs, Forgeries and the Athenian Decadrachm'
http://stannard.info/stannard_fischer_bossert_dies_hubs_forgeries_and_the_athenian_decadrachm.pdf

I recently read an article by Clive Stannard and Wolfgang Fischer-Bossert which I feel certain you all would enjoy (URL above). They discuss ancient and modern methods. Excerpts from page 6:

"A fourth reproduction is the making of copies from coins themselves, which
reproduces on the product the individualities of the model, which arose both from
imperfections in the original dies and from the process of striking. This can be
done by casting from moulds, but it was also possible to prepare ‘transfer dies’
from hubs cast from impressions of individual coins; the coin itself is the positive
reproduction of the negative die, and a hub cast from it strikes a derivative negative
die, with all the individualities of the model. Such hubs were used in antiquity – at
least by forgers, frontier communities without official mints, and peoples beyond
the frontiers – but there is no evidence that they were used in more regular mints."

"Coins themselves can serve directly as hubs: Markus Peter has shown
experimentally that a silver denarius can be hammered directly into hot iron, to
make a transfer die."

 

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