Making a Forged Platinum Ring

This project has many advantages for the jeweler who doesn’t have very much experience working with platinum.  This project demonstrates platinum’s malleability, employs high temperature soldering technique and is a challenge to polish.

 

 

To make this ring, you will need a torch, using propane/oxygen, natural gas/oxygen or hydrogen/oxygen.  I was using a Hook torch, with natural gas/ oxygen for this project.  Do not use acetylene for working with platinum.

I use the back of a Wesco dish crucible as a soldering surface, but any fused silica or alumina block will do.  Be sure not to use a charcoal block.  Carbon will contaminate your metal.

 

You will need a pair of safety goggles, with a #5 or #6 rating to protect your eyes.  If you like to work with a soldering pick, be sure you are using one that is made of tungsten.

 

You will also need a set of files, a sand paper stick, assorted silicon wheels, a jeweler’s saw with blades, a ring mandrel, a bench block or bench anvil and a hammer.  I used a chasing hammer for this ring.  A pair of bow-closing pliers are also required.

 

Assorted polishing wheels like a brush, a felt, a buff, and an inside ring buff will be needed.  Be sure to include platinum polishing compounds.  I use 800 for the first finishing after the sand paper, then 1500, followed by 4000 grit with a final polishing compound of 8000 for luster.

 

You will also need a stone setting bur of the right size for the stone, a 41 flat graver for the bright cutting after the setting of the stone and a flat bezel pusher, or setting punch to set.

 

Materials include a 3x3mm piece of square platinum stock, 2” long, 1/2”x1/2” piece of 20 gauge platinum stock, ( Pt900, platinum iridium), some 1700 platinum solder and some 1500 platinum solder, and a 1/4 ct. diamond.

I am assuming that you do have a flexible shaft motor at your disposal.  Be sure you have cleaned out your tray and start with a clean workspace.  Let’s begin.

 

Step 1 - Annealing the Platinum Stock
We begin by annealing the platinum stock.  The stock is heated to about 900 C, which gives it a bright orange color.  We hold this temperature for one minute and then quench.

 

Be sure not to over anneal, as that will cause grain growth.  However, if you under anneal it, the stock may not be dead soft.

 

Step 2 - Pre-Shape the Stock
Using a rolling mill, we can roll the center of the stock thinner and thus wider, to begin the shaping of the ring.  We also roll one end in the opposing direction, to make it wider vertically.

 

Be sure your rollers have been cleaned, so that you can avoid contaminating the platinum.  Contamination will happen if small particle's of another metal, which may cling to the rollers, gets pressed into the platinum surface.  If you then anneal, these particles will melt into the platinum and contaminate it

 

Step 3 - Forging the Platinum Stock
Having started the shaping with the rolling mill gave us a good indication where to forge the stock to blend the shape into an attractive form.  I am using a chasing hammer for this.

 

A hammer with a rounded plane would be the best choice here.  We want to shape the metal as smoothly as possible, without doing too much damage to the stock.

 

Overlapping blows will do fine.  We forge the one end flat in a horizontal manner and the opposing end in a vertical manner.

 

Step 4 - Bend & Shape the Shank
Using bow-closing pliers, we bend the stock round.  This will mar the surface of the platinum somewhat, but the marks can be easily removed with the file.

It is helpful to modify the pliers by rounding the edges of the pliers with a Cratex wheel or a file.  This will prevent deep marks on the stock as you bend.

 

On some projects I actually place a small piece of leather or tape between the jaws as I bend the stock to prevent marring

After the bending you will need to anneal the stock again.

 

Step 5 - Rounding the Ring Shank
The stock is then placed on a mandrel and hammered round.

At this point you will start thinking about the finger size and either remove metal or hammer it up a bit.

 

 

 

A good guide is to make a sterling model, before you work with platinum.  The model should be in three phases for each forged design:
- one would be stock with the ends and the center forged,
- the next should be the bend and hammered ring as you see it in this picture,
- and the third should be the finished ring made of sterling.

 

 

Step 6 - Trimming the Excess Material
Trim off some of the excess platinum using a jeweler’s saw.  The ring is starting to take shape.

 

 

Step 7 - The Forged Ring
Here we see what the forged ring should look like at this point.  The finger size should be set, and the ring is ready for filing, sanding and finishing.

 

 

 

 

 

Step 8 - Shaping the Ring with a File
Using a #4 barrette file, we file the ring and remove any marks the hammer or the pliers left on the ring.  Using an abrasive wheel, smooth the inside of the ring.  Before we move to sandpaper, we stamp the quality mark and trade mark on the inside.  The mark reads Pt900 for 90/10 iridium platinum.

 

Be sure to cross file the ring.  Cross-filing is done by filing in directions 90 degrees from one another, similar to a Florentine.  This will prevent deep grooves in the ring which will have to be removed.

I find that a sponge file from a beauty salon works great for platinum.  It conforms to the shape of the ring and is disposable.

 

Making a Forged Platinum Ring continued