Hand Making an Engagement Ring

As long as I was making my girlfriend a fairytale storybook, I thought it made sense to make the ring as well. Here are the major steps I took to go from a hunk of platinum, a setting, and a diamond to a finished diamond ring in just over one day.

You should note that, for the machining technique I used, access to the proper tools is critical. If I didn’t have that access, I would have used the lost wax casting technique instead. To get access to the tools, I worked with a great fella named Adam at DIYWeddingRings.com. If you don't have access to these tools, hopefully you can improvise based on what I've shared.

Design

The question that all men ask is, “how do I get her a ring that she will love?” It’s a tricky one because, for some of us, the element of surprise is important. How do you surprise someone with a ring that you also know that she will love?

My solution was to have a distant friend of hers send out a Survey Monkey survey asking for help on a new online jewelry business she was starting. Of course, the survey only went to my girlfriend ;)

This gave us the stone cut, the band style, etc. that we needed. So off to the design races! Or so I thought… it turns out that I missed one fundamental question. I’ll tell you more about that later.

Method of building

Given the simplicity of the ring style that she wanted, I chose to machine the ring via traditional metal working tools versus using the lost wax casting technique that is used by all the retailers. In theory, machining will result in a stronger ring with less wear and tear over time. In practice I really have no idea if this will actually have an impact. I suppose I could have evaluated a bunch of rings made 60 years ago but…

I started with a hunk of platinum and extruded it through a hand-cranked extruder. The extruder has several sizes and I simply cascaded down in sizes until I reached the desired diameter. It took 10-15 passes to get it to the right diameter.

After any step that reshapes the metal, it's important to anneal it. With platinum it’s important to anneal it on something clean so that it doesn’t pick up other metals during the annealing process.

Once the metal was the desired diameter, I cut it to size

It should end up as a cylinder with flat ends because, at the next step, it is going to be bent around into an oval and you want the two ends to meet up as cleanly as possible.

The next machine is a glorified pseudo male/female type machine. On the one side is effectively a hollow half cylinder (the female). On the other side is a full cylinder (the male).

By manually pressing the two together, the full cylinder will sit inside of the hollow half cylinder and anything in between will be bent to make the shape. I put the platinum bar between the two and cranked it. That rounded out a small portion of the platinum rod. After repeating this process 7-10 times, I was able to create an oval shape out of the platinum with the bar ends nearly touching each other.

Of course, after this the platinum must be annealed.

The next step was to braze the oval together to form, for the first time, a solid ring. Make sure the oxy-acetylene torch is ready to go, place the solder over the gap, and get fired up. Unlike traditional soldering techniques e.g. circuit boards, you need to heat up the platinum material first until glowing red. Only then due you place the heat on the solder, which liquefies and flows into the platinum, creating a solid joint.

After that, it's good to pickle the platinum.

This stage is the first time that you get to see a true circular ring. First step is to hammer in down on a mandrel until you have a pretty good circle. Flip the ring every few hits so that it isn’t wider on one end versus the other. After that, I used this machine here, which can either stretch or compact a ring, to make sure the ring was circular and was the right size

The cavities are all different sizes and, after finding the appropriate cavity size that fit the ring as it was, I used the manual press to compact the ring until it got too small for that cavity. I then moved it to the next cavity. After each press, I flipped the ring so that it would stay symmetrical. It took 5-10 presses to get the size I wanted (ring size of ~4 1/2)

Throughout the process, there’s an awful lot of sanding. The first time that I did any significant sanding was after creating the circle.

Sand the sides of it on a flat sanding surface, as pictured. Also sand the sides and the interior using a dremel, hopefully that is affixed and therefore not moving aka move the ring not the machine.

It was useful to get the basic sanding completed before adding the setting because I could get more aggressive without worrying about hitting the setting.

Her ring size, I thought, was around a 5 so you might be surprised that I created a 4 ½ size ring in the previous section. The reason is that the next step was to cut an opening in the ring to place the setting. This expands the size of the ring by, roughly, the width of the setting at the base. You’ll see that I made two cuts, perpendicular with each other and at a 45 degree angle to the side of the ring.

The setting, which I bought pre-made, had to be popped in to the ring securely. Although the professional jeweler I was working with did this (because it's important to get right and I was paying him), it can be done by an amateur.

Background on why it's important: even though we’re going to braze the setting with solder, it’s useful to have tension on the setting. So I made sure the opening that I cut out was just a bit smaller than the base of the setting, plied the two sides apart and we inserted the setting. The last photo shows the setting inserted

From there, it was time to braze the setting. This requires an oxy-acetylene torch that gets up to temperatures above 3000 degrees. It’s hot! And bright. Like, wearing sunglasses indoor bright. It is critical to get this stage right because this is the weakest part of the ring. The process is straightforward, if a little nerve wracking.

Heat the platinum until it's glowing red.

Then hit the braze with the torch, taking care not to knock it off and certainly don't heat it up so much that the platinum melts at all. All in all, it’s 20-40 seconds of heating followed by ~2 seconds of brazing. If you leave it on too long, it’s quite easy to ruin the piece.

After the setting was complete, I moved to the finish work. Basically, sanding the inside and outside of the ring. For some of it, I was able to take advantage of a rotary tool but a decent amount of it was good old fashioned hand sanding. The pencil tip sander was helpful to get rid of the solder that was a little evident near the joints.

I ended up going down to ~1500 grit

Setting diamonds is actually a sub specialty, kind of like how you have primary care physicians and specialists. Given how much a diamond costs and how long it needs to stay put, it’s pretty important that it stays in for the next 50 years. So I went to a setter in downtown San Francisco who was nice enough to let me take some photos while we was setting the diamond.

I finished the ring and I put it into the fairytale storybook proposal book that I made for her as well. She said Yes so I consider that a big success!

Lessons learned:

Surprisingly, to me at least, the hand made ring has gotten more oohs and ahhhs than the fairytale storybook, which took probably 20x as much time to make. Lesson learned - there appears to be something really special about hand making a ring that your sigO is going to wear every day for the rest of her life. I'm really glad that I put in the effort to do this and think that, if you are so inclined, you should consider doing the same!