Test Cuts and Bankers' Marks Empirical Playtime

I went over to my father-in-law's and in his shop, I told him about
the origins of coinage and ancient fakes. I showed him my chopmarked
Spanish Dollars. We got out some tools and set to work.

Now, these are modern tools and modern coins. I believe than in
ancient times, the coins were softer and so were the tools. My goal
was to see if I could punch letters on modern Lincoln cents without
leaving a dimple on the other side. After some practice, I could. It
took about 10 coins, maybe 30 strikes in all, but it worked out.

To back the coin, the best block was of aluminum. Pine and maple were
too soft. Iron (the anvil of the vice) was too hard. Aluminum in
ancient times is, if I recall, known from only one citation. Again, I
think that for an ancient silver coin and an ancient iron tool, then
hardwood might be best after all, not soft wood like pine or cedar.

You have to hold the punch exactly vertical and strike it once, just
so with the hammer, in this case a small ballpeen.

Next experiment: using cold steel chisels to cut through Lincoln to
reveal the tin underneath the copper sheath.

None of the cuts I made with the punches pierced the copper down to
tin. Yet, the banker's marks I have seen -- as on two Cato quinari I
have -- are all deeper than the ones I made.

None of the Spanish 8 Realese with chopmarks show any dimpling on the
opposite sides. These would be 18th or 19th century tools. What that
means, I do not know.

High Plains Writer wrote:

I went over to my father-in-law's and in his shop, I told him about
the origins of coinage and ancient fakes. I showed him my chopmarked
Spanish Dollars. We got out some tools and set to work.

Now, these are modern tools and modern coins. I believe than in
ancient times, the coins were softer and so were the tools. My goal
was to see if I could punch letters on modern Lincoln cents without
leaving a dimple on the other side. After some practice, I could. It
took about 10 coins, maybe 30 strikes in all, but it worked out.

To back the coin, the best block was of aluminum. Pine and maple were
too soft. Iron (the anvil of the vice) was too hard. Aluminum in
ancient times is, if I recall, known from only one citation. Again, I
think that for an ancient silver coin and an ancient iron tool, then
hardwood might be best after all, not soft wood like pine or cedar.

You have to hold the punch exactly vertical and strike it once, just
so with the hammer, in this case a small ballpeen.

Next experiment: using cold steel chisels to cut through Lincoln to
reveal the tin underneath the copper sheath.

None of the cuts I made with the punches pierced the copper down to
tin. Yet, the banker's marks I have seen -- as on two Cato quinari I
have -- are all deeper than the ones I made.
======
Not tin. Zinc.
========

None of the Spanish 8 Realese with chopmarks show any dimpling on the
opposite sides. These would be 18th or 19th century tools. What that
means, I do not know.

"High Plains Writer" wrote in message
om...
I went over to my father-in-law's and in his shop, I told him about
the origins of coinage and ancient fakes. I showed him my chopmarked
Spanish Dollars. We got out some tools and set to work.

Now, these are modern tools and modern coins. I believe than in
ancient times, the coins were softer and so were the tools. My goal
was to see if I could punch letters on modern Lincoln cents without
leaving a dimple on the other side. After some practice, I could. It
took about 10 coins, maybe 30 strikes in all, but it worked out.

To back the coin, the best block was of aluminum. Pine and maple were
too soft. Iron (the anvil of the vice) was too hard. Aluminum in
ancient times is, if I recall, known from only one citation. Again, I
think that for an ancient silver coin and an ancient iron tool, then
hardwood might be best after all, not soft wood like pine or cedar.

I'm thinking lead, or maybe pewter or tin would be even better.


You have to hold the punch exactly vertical and strike it once, just
so with the hammer, in this case a small ballpeen.

What size letter punch were you using?
When I tried punching the inaugral RCC 50c Primative, I used 6mm (1/4")
punches, but they were too big - too destructive. 1/8" would have been
perfect.
(Stu, FYI, I sent you the second, unpunched Primative)
The "coin" ended up warped, like a potato chip. Either that, or the punch
was too light.


Next experiment: using cold steel chisels to cut through Lincoln to
reveal the tin underneath the copper sheath.

None of the cuts I made with the punches pierced the copper down to
tin. Yet, the banker's marks I have seen -- as on two Cato quinari I
have -- are all deeper than the ones I made.

None of the Spanish 8 Realese with chopmarks show any dimpling on the
opposite sides. These would be 18th or 19th century tools. What that
means, I do not know.

Well, the Pieces of 8 were (are) big thick heavy clunkers compared to a
Zincoln. More "meat" to absorb the blow. They had access to hardened and
tempered high carbon steel in the 18th C. Maybe not chromium based tool
steels, but way harder than silver - even work-hardened silver.
A leather bag of very fine lead shot (just hypothesising here) may have
served as a nice base for chopmarking silver coins without harming the other
side. (Maybe)

Thanks for the food for thought.