Sometimes I find that a lack of inspiration while making jewelry can lead to really interesting innovations. In this tutorial, I’m going to show you a technique I came up with during one of these times. I call it “faux shibuichi.” Shibuichi is an ancient Japanese alloy of silver and copper which creates really interesting oxidation possibilities. I particularly like the look of shibuichi when it has been reticulated. You can read a little about this alloy here.
This tutorial assumes that you already know the basics and have the basic tools. If I breeze over something and you have a question about it, please let me know. I’ll be happy to clarify anything for you (can you tell I worked in call centers for many years? “I’ll be happy to help you with that today!”).
Here’s what you’ll need:
– 20 gauge copper sheet cut into about 1×1 inch squares.
– Fine silver metal clay paste.
– Medium or easy paste solder.
– 16 gauge silver wire to solder on.
The first thing you need to do is prepare your fine silver metal clay slip. It really doesn’t matter how thick or thin it is. Experiment with it and see what you prefer. My slip was pretty thick, about the consistency of thick yogurt. The important thing is to make sure it’s very smooth! You don’t want any chunks in the slip because they won’t adhere to the copper and will flake off when you’re done.
I didn’t prepare the copper in any way, except to round off the sharp corners with a file. Yeah, I know. I need a new soldering board. This one is about at the end of its useful life.
Spread a layer of metal clay paste over the surface of the copper with a pallet knife. Some spots I left pretty thick, and others I left thin enough that some of the copper showed through.
Next, break out the torch! I fired these pieces while the silver paste was still wet. If you heat it slowly, the paste will have the opportunity to dry and you’ll experience very little cracking. Like this:
If you heat it faster, the paste will crack and peel up onto itself, like this:
Either way is fine! Try out different methods to see which you like best. If the paste peels up, you’ll have more of the copper exposed. If it doesn’t, you’ll have more silver on the surface. It just depends on the look you’re going for. I prefer a little to a lot of cracking, so I heated them pretty fast.
Continue heating until the paste is dry and the binder has burned off. Once the copper is glowing, get aggressive with the heat! Heat it until the silver melts and flows. As you drag the flame over the surface, the melted silver will follow and you’ll get some really awesome reticulation. You want to make sure that everything has had the chance to flow. See where it’s still white? If you leave it like that, the silver will flake off because the layer of oxidation between the silver and copper prevents fusing.
Here are both pieces, all fused up! Aren’t they pretty? Well, maybe not just yet.
Now here’s where things start to get a little weird. Under normal circumstances, you would want to pickle your pieces to remove oxidation and prepare the surface for soldering. While you can certainly do this, let me caution you against it. DON’T DO IT! That was probably closer to bullying than cautioning, but you get where I’m coming from. Here’s why I’m so against it:
First, by pickling you’re basically depletion gilding the silver and leaving a layer of fine silver on top. That means you’re removing the copper oxides (well duh! That’s what pickling is for, right?). But we want the oxides because that’s what shibuichi is all about!
Second — and I don’t know if it’s just the pickle I’m using or if this would happen with any kind of pickle — the pickle turns blue almost immediately. Also, a crusty, green/blue layer is added to the surface of the silver. If you’re interested, I’m using PickleIt, which you can get at metalclaysupply.com. It’s supposed to be “a safe alternative” to regular pickle. Normally, it works just fine on copper and silver, and I really like it. I only have to change it every couple of weeks, but while I was working on these charms, I had to change it twice — and that was after only 10 charms!
Third, it’s just way too much work. The green/blue scum does come off with some polishing and a little elbow grease, but then the silver is exposed and the oxides are gone. Now you have to flow the silver again just to get those back. You might as well just save yourself the hassle and not pickle.
Here’s a photo of the first piece after fusing. All I did was polish it with a bristle disk on my flex shaft.
Here’s a photo of the second piece after pickling. This must have been right after I changed the pickle, because the green/blue scum isn’t too bad. Some of my first pieces were completely covered! Also notice that you can’t see any silver. What’s not covered by scum is copper colored. I’m not sure why it didn’t remove the copper from the silver. If you know why this is, I’d love to hear!
And here’s what it looked like after polishing. Big difference when compared to the one that wasn’t pickled, right? It’s very silvery, whereas the other one was almost a gunmetal color.
Next, I’m going to solder on the silver coils. Even though the first piece was slightly grey (which is a characteristic of shibuichi), I had no problems soldering, except when I tried to use hard solder. Because hard solder has a higher melting point, the surface flowed on the first few pieces I made. This creates more oxides and I found myself having to re-solder. What a pain! Once I moved down to medium solder, I had no problems.
Before you jump into soldering, let me tell you about a couple of other things you need to know. Sometimes, there are pockets of air (or pickle, if you threw caution to the wind) between the silver and copper. If you heat the piece without eliminating all of the tiny air pockets, the pockets can explode. Literally. This happened to me once when I was working on a piece and missed an air pocket. It snapped, and a tiny piece shot across the room. I was terrified I was going to take one in the eye! Fortunately, these pockets are pretty easy to detect. Just inspect the surface for anything that looks like a blister. If you find one, poke it with the tip of your fingernail (or, if you’re a nail-biter like me, use the tip of a needle tool). If it leaves a dent, you found one. If it doesn’t, you’re probably good. If you DO find one, heat the piece slowly until it flows again. Make sure to melt that spot down all the way.
Next, if you see any spots that are still very silvery before you polish, they’re probably going to flake off. If that’s the case, re-melt it! Once you’ve taken care of these things, you can polish and solder.
Here’s the first piece immediately after soldering.
On the second piece (the one that was unfortunate enough to be pickled), I allowed the surface to flow a bit while soldering to regain the oxidized surface. However, I still had to take care not to polish it too much. Even though it flowed again, the oxides on the surface were not quite as strong. Here are both pieces all polished up!
Here’s what I was telling you about. I should have flowed all of those bright silver spots out, but I didn’t because I wanted to show you what to look for. See that spot in the red circle?
Just a quick scrape with my fingernail, and this is what happened.
Other than that, I’m pretty happy with them! What do you think? If you try out this technique, I would love to see photos of what you came up with. You can post them to my Facebook fan page here. If you have any questions about this technique, feel free to post your questions below, or on my Facebook page.
Happy faux shibuichi-ing!