Hi Crew,
Sorry about the delay in replying; the clutch went out on my poor Fiero last Friday (actually, not the clutch - I thought the throw-out arm had broken, but it turned out to be just the - now unavailable - slave cylinder bracket. From $$$$ to $$). So I've been sidetracked. I'll just reply to the comments en-masse.
We do this on a regular basis. There is also a Yahoo group devoted to
> doing this "sca_moneyer".
>
> Annealing:
> You want to heat it up to where it is just red, and then let it cool.
> We usually get about 3 passes before you have to anneal, some times > 2.
>
> Punching
> We used to use the stirrup punches, but they are not great. What
> works better and are commonly available, are shim punches. I also
> recently noticed one (quality unknown) at harbor freight "46628-3VGA". > ~ $12.00.
>
> Our group has had custom punches that are essentially the same thing,
> (in a single size) made.
>
> A 2" diameter is HUGE for hand striking, 1" is pretty big but doable.
> It depends of course upon how big a hammer you can manage. Some people
> in our group prefer a 4 lb hammer swung two handed, I use an 8lb
> sledge that I have cut town to about 1 foot.
>
> Striking a lot of coins also works best as a 3 man operation. A
> placer, a die holder and a striker.
>
> Where are you located?
>
> jk
>
Thanks for the link to the moneyers' group. That's exactly my intent.
I mis-typed the size; I was thinking of 1" dia. I've measured some of the real coins I have, and the sizes for the common denominations are closer to 3/4". A Venetian Gazetta (~1550) is 18 mm dia & 4.25 mm thick; an English penny (~1250) is 17.5 mm dia & 8.75 mm thick. With the metal being relatively thin, I hope the punching of the blanks will be somewhat easy (hah!). The HF punch & die only goes up to 5/8".
I've seen contemporary engravings of a one-man operation - cross-legged on the ground. I guess I'll find out.
I'm in the "mountains" of South Carolina, right next-door to the moonshiners.
Most slip rolls won't be stiff enough to roll down silver ingots.
> Maybe a big industrial model might work. Jewelers use a rolling mill
> that is considerably stiffer in construction than a typical small slip
> roll. What is the thickness of your bars? I have a medium-sized
> Durston rolling mill, and the max it can handle is about 6 mm thick.
> It has a 4-1 reduction gear, and still requires a LOT of elbow grease
> to roll wide ingots. It has 130 mm wide by 60mm diameter rolls, in a
> heavy steel plate frame. Compare that construction to a typical slip
> roll, and you can see the difference.
>
> The arch punch will only work on very thin metal -- coin blanks are > too thick, IMO.
>
> Regards,
>
> Bob
>
I have an Akro Mills roller, only 6'' wide that I picked up at a school district auction. I've rolled some nickels down to about 5 mm, so I hope that it will handle the silver, as well. The nickels did require some real effort, though. Maybe I will have to start with some gentle hammer reduction, using my BAH. I don't know the thickness of the bars offhand. They are the typical 1 troy oz. commemorative bars that I bought at a coin show; some ugly, slightly tarnished zodiac designs for which I paid only 50 cents above market value.
Why do you want to use fine silver? It will wear very fast. Also when
> annealing you need to protect it against fire staining/scaling. 99.9
> will not fire stain like sterling silver (95% silver 5% copper) but
> will some. You can prevent by using a 50% mixture of alcohol
> (denatured hardware stuff) and boric acid (roach kill). Apply the
> mixture with brush, lite up and let alcohol burn off. Then using
> ox/acty torch with large bushy flame and little on the acty heat to
> dull red. Quench after about a minute so the silver does not tear or
> crack when you pick it up. Use a pickle to clean the silver before you roll. >
Fine silver was the standard metal for coining in the Middle Ages. Any alloying was considered as nothing more than a debasement of the money (although that was real popular, too).
Thanks for the formula.
Can I ask you to post some pix when you have struck some coins?
> (Of the dies, too - or better still, the whole process?)
>
> This sounds like a lot of fun.
>
> Jeff
>
Sure, I intend to document this process. I probably won't get started until this summer.
Fun is the only reason I'm doing it!
There seems to be some disagreement on the particulars of annealing the silver. I guess I'll experiment with that.
Another question (I haven't had a chance to check the Yahoo group yet): What should I use for the dies? I had thought of some hardenable tool steel, but it would have to be somewhat forgiving about temperature; I am somewhat color blind (doesn't pose too much of a problem, though).
Again, thanks to everyone who replied. I can be contacted directly at jgandalfatmindspringdotcom (the displayed return addy is anti-spam phony).
Joe