I really don't like the expression "think outside the box". Thinking outside the box makes you come up with hundreds of unfeasible solutions to your problem. However, if you define the borders of your problem's box and actually get to know what's inside, that content will solve your problem 99.99% of the time! It's about how to put the tools together, not to reinvent the wheel.

Remember KISS, keep it simple stupid.

The Quest for a Ring Necklace Pendant

I have to admit, I have a bad habit. Whenever I see something that entices me, I directly go in my head to the thought: "I can do that as well!"

Some may say this is an early onset of the "dad-like" antagonism of calling professionals to fix certain things, but I actually don't find the appeal in digging through waste-water to fix a broken pipe. For me, that sentiment is more rooted in creation, trying new things and learning new skills.

The Spark of Inspiration

0:00

/0:11

My inspiration to try goldsmithing comes from a video I watched on YouTube. JerryRigEverything is, what his name already suggests, a creator who tries, tests and modifies tech, but also builds and rigs almost anything. One of his projects was to build the wedding ring of his fiancé out of a piece of her wheelchair. It's a really cute story and I recommend checking it out!

Since I have always loved to work with metal, but welder, lathe or mill do not fit in my apartment, goldsmithing seemed like a nice avenue to explore.

With the enticement sorted out, I just needed something smart and quirky to do. And this design by Desideria Collection came calling. They produce a necklace piece that comes right out of the pocket puzzle genre. The "Ring Necklace" can hold a ring securely in display without any hinge or mechanism to hold it and can be put on without taking off the necklace. A really amazing design and I endorse their page and business fully!

But let's cut to the chase, shall we?

Planning My Approach

Most goldsmith workshops have one heavy-duty machine: a roller to cold-roll the bullions in different gauges roughly to size. If you're doing this regularly and even multiple times a day as a business, this can greatly speed up the process and increase quality of life, while not being necessary.

You could take on the journey, throw the piece on your anvil and smash it like the Hulk into submission. A workable solution, but requires an anvil and probably very lenient neighbors if you happen to live in an apartment building.

One of which meets me, so I had to come up with another idea. Instead of manufacturing the design from a solid piece of gold, I would take a round gold tube to achieve the perpendicular shift between the vertical and horizontal segments with minimal use of a hammer.

What I needed for this pendant project:

Gold profile ~100mm with an outer diameter of 3mm
At least one steel hammer and a mallet
Flat pliers
Some fabric tape
Gold solder
Boric acid and (denatured) ethanol
Flux
A small blow torch
A third hand
A rotary tool with some cut and drill attachments
Files
Fine grid sandpaper and polishing compound
PPE and some fire protection

With these tools and materials, it should be perfectly possible to make a replica of the Ring Necklace pendant of decent quality.

Testing with Copper First

0:00

/0:39

In any project, one should never forget about the importance of proper planning, including prototyping, when the investment into that project exceeds the comfortable threshold of risk. In this case, the risk wasn't too high, since gold holds its value pretty neatly, I could resell scrap with minimal loss.

However, it turns out that gold is not that easily accessible, especially in a specific extrusion format and dimension. I didn't find any source within the Netherlands that provided round gold profiles or even at all in retail. So I opted to source the raw materials from a UK website that provided the piece in the designated format.

In order to avoid complex tax filings between countries (gold bullions for investment purposes are taxed differently than raw materials), I tried to stay within the bounds to still be taxed right through the website and just buy one piece. And here arises the necessity to prototype the manufacturing process regardless.

Selecting a substitute for gold is fairly easy. Copper pipes are a common choice in any hobby store for thermal installations. Copper is very similar in thermal conductivity, melting point and elastic modulus, which makes it perfect to test out how the deformation affects the material.

What I learned from prototyping:

It's not possible with hammering and filing alone to remove the separation of the metal sheets at the ends to a negligible degree. This isn't entirely cosmetic, since this is also true for the holes in which the chain may get stuck sliding through.
Buckling at the bending radii is a concern relative to the wall thickness. Due to the perpendicular shift in orientation, the vertical elements buckle inwards the closer it is to the apex of the bend. Filing this off uniformly may break through the material.
Asymmetric bending may introduce visual asymmetries at the bend on the horizontal element.

The Real Deal

Shaping the Gold

Beginning with the plain gold tube, I measured and marked the middle and outer bending points. Now, despite the workpiece being hollow, some hammering is required to bring it into shape. An anvil is still out of the question and my makeshift alternative requires a hard surface and the corner of the steel hammer as a prop-up bending die.

Given, this is not in any way sufficient to perform a clean bend of a tube, but since buckling of the tube is actually desired in this case, the end justifies the means. Upon the first strokes I noticed considerable difference in malleability between the prototype and the gold piece. The website didn't give an indication if the extruded gold was heat treated in any way. Enough reason for me to believe that the piece is hardened by the extrusion process and needs to be annealed before proceeding with finishing the sharper bends. This could lead to breaking off of the delicate wings.

Gold tube after initial bending attempts

Heat Treatment (Annealing)

Annealing is the process of reducing stresses within a metal that may have formed through different processes. Most common is the hardening through deformation like bending, or in fact extrusion. The metal is therefore heated above its recrystallization temperature and slowly cooled down, so that it recrystallizes in a less stressful microstructure configuration.

In process engineering this can get quite complicated with heat cycles for different workpiece thicknesses and alloys as time and energy costs often play a huge constraint. However, in goldsmithing circles, I have found that people just recommend to "hold it into the fire until it faintly glows dark red, that should be alright then". And what's good enough for them is certainly good enough for me.

The cookbook continues as follows: Take equal parts of boric acid and denatured ethanol and mix it. Before the workpiece touches any flame, it should be dunked into this mixture. The ethanol works as a carrier liquid to cover and adhere to the workpiece surface. The evaporating ethanol leaves a film of boric acid on the shiny metal to protect it from unnecessary oxidation during the process.

In my case, since the tube was still fairly straight, I also opted to not take out the torch, but utilize my gas stove to be able to heat up the workpiece much more uniformly. This worked like a charm after dialing in some lower setting. Definitely take your time to not go above the right temperature.

After the annealing it was noticeably easier to work the gold. I tried to finish the rough shape, bends and buckling of the tube, but left the ends not yet completely squished down. Why I did that will come to light in the next section.

The Soldering Challenge

Coming from my background, soldering involves a tin wire in one hand and the soldering iron in the other, with the goal of joining two conductors with the minimal amount of solder possible. Naturally, without any critical assessment, I went for a gold wire solder.

Now, the biggest difference in gold soldering is that despite its being called soldering (by goldsmiths), it is actually brazing. This is arguably the same, however brazing normally involves higher temperatures (roughly above 300°C), which consequently means a higher risk of oxidation and hence failure of the braze.

Next, while it's still desirable to use as little solder as possible, the goal is not to maximize electrical conductivity within the joint, but make it look as nice as possible in the end. And this may require more solder than originally thought.

At this point I unfortunately started to run into time constraints. Initially, this pendant project was deemed to be a gift and the giftable date crept ever so closer. My first soldering attempts, trying to apply the same principles of tin soldering, failed pretty quickly.

One big problem was the size of the torch I was using. I knew that because gold is such an excellent conductor, the heat I put into the workpiece will quickly flow through the entire mass and dissipate through the surface area. Following that, it was hard to make the solder flow into the solder joint or area I wanted it to.

But with this realization, I had used up all of the solder I acquired earlier and shipping from the UK was not in the time budget anymore. Instead, I made some calls to local goldsmiths, politely asking if they would sell me some gold solder.

The Dutch Gold Market Quirk

And before I get to the person who made my day, I have another little excursion. Not being originally Dutch, I didn't know a fact about the jewelry market here. I always thought yellow gold jewelry comes in 9, 14 and 24 karat, which refers to the gold content in the alloy: 33.3%, 66.6% and 99.9% respectively.

Since gold is a fairly soft metal, 9kt gold, while being also the cheapest, is not only the most durable, but is also supposed to be the easiest to work with and therefore an excellent choice for me. The Netherlands however, in their infinite wisdom, decided to drive a different path. For whatever reason, there is a legal limit to gold.

So, as a person that sells jewelry, if you were to sell a 9kt gold ring, you cannot call it a gold ring. It may look like gold, it may contain gold, but it is a "silver ring", which obviously is less marketable than a "gold ring". Hence, nobody in the Netherlands actually sells 9kt gold. Tough luck I guess.

But enter the stage Sonja Hunefeld from Odinski Jewels in Den Haag. In fact, also special thanks to Dafne Meesters and Laurie Hermeler for directing me and explaining the Dutch 9kt situation to me. When I was stranded without any solder, she agreed to sell me a piece of, not 9kt, but 14kt gold solder plate, with which I was able to at least continue.

Going back to the actual issue at hand: The two layers at the ends had to be joined by soldering. Now, with the additional information on how to approach gold soldering, I cut two pieces of the gold solder plate in shape to just fit into the squished tube. The plan was to clamp the solder inside the tube in order to heat up both workpiece and solder uniformly and let the solder not escape anywhere it wasn't supposed to flow.

Done as said and it worked like a charm. It has to be said that there is a degree of color difference between the 9kt and 14kt gold, however, this is expected to be negligible once the piece is done with a mirror finish.

[Upload: Soldering process video - yannick-schulz-goldsmithing-soldering.mp4]

Surface Finishing

Once the shaping and soldering part is finished, it gets to the nitty-gritty part of the job: Making it look neat. At this point, the piece looks quite beat up, bulges and buckles from the nature of the tube, a few oxidation spots here and there and it still misses the eyelets for the chain.

The latter part is easily managed by milling out a diameter at the appropriate locations at the ends of the wings with the rotary tool. Furthermore, good practice is to keep excess length of the workpiece until the bending is done, so it can simply be cut to spec at this point.

Much more difficult is the act of grinding down the surfaces and edges. Not because it's a particularly strenuous task, but because of what was learned in prototyping. Grinding too greedily can result in a wall breakthrough in particular areas, such as the buckling in the bending apices.

But the plan was pretty clear: getting the surfaces flat and shape the rest of the piece with a medium-grit file, use coarse sandpaper on all negative spaces, such as aforementioned dangerous areas and consecutively increase the grit up to 5000. All that would be left is polishing the piece with jeweler's rouge. Jeweler's rouge is a fine reddish colored polishing compound that leaves a close to mirror finish.

However, not speaking from particular experience or authority, I don't really think it matters too much which compound you choose in the end. Reading up on it leaves you with more questions than answers regarding which is the best one to use and it feels more like bro science than anything else. Take what you have, is accessible or you feel most comfortable with.

But, but, but... If it just went this smoothly.

When filing down the face of the horizontal bar, it happened and I broke through the wall. When filing off the surface uniformly, there must have been some slight warping of the material from an unclean bend or the heat treatment that I didn't account for. Efforts to seal the damage by flowing more solder into it were unfruitful and at such a prominently exposed area, the color difference of the 14kt solder became just too prevalent.

Since the deadline passed, this particular project was put on hold.

Where It Stands Now

Although this pendant project didn't end up being a total win (it may in the future), the attempt demonstrates just how ingenious the original Desideria Collection design really is. What looks like a simple bent piece of metal is actually a precisely engineered puzzle that requires exact tolerances to function properly.

The flawed pendant currently sits on my workbench - a reminder of the complexity hidden within seemingly simple designs. Despite the breakthrough in the horizontal bar, you can still see how the mechanism would work: the way the vertical segments create the perfect cradle for a ring, and how the whole piece could slide onto a chain without any moving parts.

Even in its incomplete state, the pendant showcases the brilliant engineering of the original concept - a true pocket puzzle translated into wearable art.

All Posts(13 posts)

Blog Statistics

All Posts(13 posts)

Blog Statistics