Gimme a ring, or 2 or 3
Gimme a Ring!!
For ages I’ve wanted to make fine hand crafted silver jewellery. So last December I thought I would. After reading several ways of casting, machining and forging silver pieces online I thought I’d give it a go. Starting with a few rings for fingers, other types of jewellery such as bells for toes will follow later.
Now as some of you will know silver is a precious metal and can be expensive depending what purity you want. Turns out one of the best ways as I can see it is to use old silver coins, I find that American quarter and half dollars are best for size and pre 50s coins are 90% or more pure silver.
This Half dollar was minted in 1943 and with it I made a rather nice woman’s ring for a very close friend, but I’ve since then also made a mans ring for myself from a 1920 coin, with more wear on it, both turned out very nice!
A coin such as a half-dollar needs to be reduced in diameter to the rough size of the person in questions finger, this is easy if its your finger but harder for someone else (especially if the ring is a surprise as it was in my case) try to get a ring they wear for internal and external size ideas, or just take a lucky guess like I did.
Tools needed, small to medium ball-pein hammer, metalwork vice.
Holding the coin in my thumb and finger on top of the vice back, I start to hammer the edge of the coin with the ball end of the hammer. I keep rotating it every few strikes to keep the edge the same size and I DO NOT hit it to hard as this can bend the coin and introduce a weakness in the metal.
Once it has been widened to between 1-1.25mm I switch to the hammers flat face and repeat the hammering and rotating to flatten the hammered edge, this keeps the coin fairly circular as you are widening it.
Then back to the ball end again, then the flat face and so on until the coin is the right size to make a ring out of and the correct width for the style it going to be. As I hammered I found that the edge seemedd to be getting uneven around the rim and the coin started to bend slightly. To remedy this I used a piece of thick steel on top of the coin and the vice back underneath to hammer it flat again, I had to do this a few times with each ring but as you can see in pics 2 & 3 above it gives a good thick flat edge to the ring.
This method of hammering means the text on the coin, date, Liberty, Half Dollar, USA, will become details on the inside of the ring, a nice touch for someone who loves America, but the same will apply with other national coins.
With the ring now nearly the right size for her finger, its time to get it on the lathe. First a 8mm hole was bored in the dead centre on the lathe using a centre drill, the scrap swarf and drillings I kept (it is sliver after all!!) for later projects.
In pic 2 here you can see the text from the coin on the inside wall of the ring, but also how wide I was able to make the edge. It is still rough hammered here.
By cutting down a M8 bolt I was able to make a spigot to support the ring while it was on the lathe for shaping and polishing. With the spindle speed set to 512 RPM I used 120 grit Emory cloth to smooth out the dents and blemishes from the hammer strikes from the ring surface. Then used the same 120 grit wrapped round a small file to shape the edge into a nice round ring.
Left: The ring being shaped and sanded on the spigot. Right: The smooth outer edge & you can see the text of the coin on the inside edge of the ring.
Next I repeated the smoothing on the lathe at 1000 RPM with 300 grit Emory cloth. This second smoothing was not really necessary but just means that the surface is easier to polish in the next step.
With the lathe still at 1000 RPM its time to polish the ring. I use Brasso and a cotton rag but any decent metal polish and scrap of non synthetic cloth will do. Several applications and buffings, in both forward and reverse directions, and the shine on the ring is clear for all to see. Talk about a mirror shine. I love the lathe, it is such a good machine, and I’m not finished with it just yet either!!
By way of careful and secretive investigation I found out that a ring size of around 18mm would be perfect for her middle finger (the size of my pinkie finger). Thankfully I have a large range of drill bits at my disposal. I wrapped the ring in multiple layers of masking tape to protect the polished surface and centred it in the lathe 3-jaw chuck that you can see in the last pic.
Starting with 10mm I rebored the hole, increasing the drill size by 2mm each time, so 10, 12, 14, 16 until finally this bad boy was used!!
A problem I had doing this was that through friction the metal of the ring would get hot, melt the glue of the tape and need to be redone. For my next ring I improved the process, which I shall detail later.
After the drilling a quick smoothing with 120 and 300 Emory was done to remove any sharp bits from the inside edge, before I hand polished the whole thing again with Brasso and a cotton cloth.
And here is her finished ring in all its splendour. Although I wish I had taken a better picture of it than this one. For a first attempt it is rather ace I think! In terms of hours taken to hand make this ring I must admit I wasn’t counting but if I’d have to guess id put it at around 16-18 total. As I make more I’ll get better and faster I recon. More to follow very soon!!
I liked her ring so much I decided to make another one for myself just a few weeks back. I used the same method to hammer and shape the ring to size and style, which took less time, as it was a larger ring. Given the trouble I had drilling out the centre after polishing on the first ring I decided to alter my methods slightly for this one.
After shaping on the spigot into a flat style mans ring with the 2 grades of Emory cloth and file I bored out the centre to 20mm first for my own ring finger. Being able to grip the ring in the chuck without the need for tape to protect it meant that the drilling process was much faster this time.
A quick smooth of the inside with 300 grit and I then used this tapered steel rod (just happened to have it lying spare in the workshop) with some masking tape to grip the ring while polishing it. This cut at least another hour out of the whole manufacturing process.
Polishing was the same method as before, in both directions.
And so the second ring I’ve made in 2012 turned out really rather nice as well. More to follow again soon.
From → Metalworking