afmetalsmith (afmetalsmith) wrote,

A finished commission!

haikujaguar contacted me a bit over a month ago about making a pendant for her. It's a significant one, since it depicts the name of the main character in a book she's writing, so I was pleased and honored that she asked me to make it for her! But before I go on about technical details, here are a couple of pictures:

Morgan's Name, picture 1Morgan's Name, picture 2

The first one is one she took, after adding the tassel to the bottom loop; the second is the one we took right before sending it to her. The design is her copyright, of course! And you can read more about it here, in her journal. :)

We had originally discussed casting as the method for turning her art into the pendant, but ran into some problems. It's a big piece- 1 inch x 3.125 inches (2.5 cm x 7.8 cm), and in general, casting works best when there's more volume and less surface area, and is less effective with large, flat, relatively thin pieces (16 ga. in this case, or 1.3mm). I did discuss it with the casting outfit we normally use, and it just did not sound like it was a great idea. Possible, yes- but far from ideal.

So then I thought of etching. I'd done silver etching before, but many years ago. I did have the materials and equipment to do it, and had been meaning to experiment with it again, but had not gotten around to it before this came up! (This is one of the reasons I like commissions- most of them do tend to push me a bit technically... or at least give me the impetus I need to pursue a technique!) A teacher I'd had a long time ago, however, swore that the etching process released very toxic gasses, so I felt that doing it outside was the only sensible course. We experimented with different ways to best apply a design I had as a digital file to metal, settled on one, experimented with various settings for the electrically-assisted etch, and were ready to go! I used a dilute nitric acid solution and a titanium plate as the other node (and I will not begin to guess whether it was the anode or the cathode; I get horribly confused!) And I brushed up on my chemistry a bit, and as best I can figure the only gas it throws is hydrogen (and not much of it)- so as I said at the time, I think that as long as I don't store it in a zeppelin, it's pretty safe. I'm glad I can do it indoors from now on!

haikujaguar and I had discusses the metal for this pendant, and we settled on the argentium sterling silver alloy. It's a bit whiter than regular sterling to my eye, far more tarnish-resistant, and can be heated in a kiln to make it stiffer and stronger than ordinary sterling gets. All these qualities made it attractive to us both, so we chose it.

There was not much documentation of etching on argentium, but what i could find said that it etched just like sterling. And mostly I will confirm that; one difference is that the argentium seemed to leave a somewhat textured surface where it etched away, but it's an attractive one and makes a nice contrast with the smooth, unetched surface. (The pendant, by the way, has the background etched away from the figures, not the figures etched into the background.) I started with 16 ga./1.3mm sheet, and etched away about 0.3mm of it. I didn't want to go much deeper, because 1mm/18ga. sheet is a good thickness for a flat pendant that size, in my opinion- it's heavy enough to feel substantial and hang well, without being hard to wear.

We'd also discussed the loops and the bail. We settled on a half-octagonal loop shape, reflecting the clipped corners of the pendant itself. Since a small bail would slide back and forth on a longer, straight-topped loop, we chose a tube bail that was the length of the straight part. The pendant will probably eventually have a steel chain, and I picked a fairly heavy tube, to better withstand such a chain; I also did not flatten the tube at all so that its rotation will even out any wear. (This tube is the one part of the pendant that is not argentium; I have not yet found a source of much argentium tubing.)

The loops themselves were assembled with fusing, not solder. Argentium fuses beautifully! And I have had some concerns about the color match between argentium solders and the metal itself; it's not as close as silver solder is to sterling, so I wanted to minimize its use. Each loop started out as 5 pieces that were carefully cut and filed to shape, then fused together in 4 steps. After that, and the etching, I threaded the bail onto the top loop, checked VERY carefully to make sure I had the pendant right-side-up, and soldered the loop-with-bail onto the top, and the other onto the bottom.

I then heat-treated the pendant to harden it, then patinated it with liver-of-sulphur. The patination would mostly be removed during polishing, but it would leave traces around the figures and so make them stand out more visibly. LoS is an interesting thing to use on argentium: the metal colors far more slowly than sterling or fine silver, which would allow one to better be able to grab some of the fabulous, oil-slick colors that a very light application of LoS can produce. Cool!

The pendant has a fairly heavy scratch finish on the back- it looks nice and is easy to maintain, so I often use it on the backs of pieces. On the front I gave it a light scratch finish all over- this removed the patination from everywhere but the edges, made the background look whiter, and acted as a pre-polish for the figures themselves. I'd hoped to be able to polish the figures with a hard felt buff, running it just over the unetched parts without hitting the background, but that didn't work; it ended up polishing the background too, in the larger areas, and I didn't want that. So I took very small polishing points, in fine and then superfine grits, and carefully went over every line of the artwork to shine it up. It took a while, but I think the results are worth it! The shine of the symbols (and the bail) plays off well against the matte-finish background, and helps the symbols to be visible when lit by a variety of angles.
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