afmetalsmith: (Default)
In general, I'm definitely enjoying making classic LinL chains using Argentium rather than fine silver. For thinner wires- especially 24-ga. and smaller (0.5mm), Argentium is a LOT easier to fuse than fine. The difference between the melting point and the flow point is a huge help here. (It's also kinda fun to see what happens when one overheats an Argentium link- usually instead of the join splitting and the ends beading up, the whole ring just magically SHRINKS. And yes, I am easily amused!)

I also really like the fact that the whole bracelet can be hardened after it's made. Bracelets take an amount of abuse second only to rings, and the sturdier I can make them, the better!

One small downside of using Argentium rather than fine silver, though, is that it does behave differently. For example, some LinL chains' specifications for gauge and mandrel size are less effective with Argentium than with fine silver. Fine silver tends to stretch in the forming process- and Argentium doesn't. This can leave one with links that are slightly too small to make weaving a chain easy, and even if one does so, one ends up with a denser chain than desired. Thus far I and others I work with have had reasonably good results keeping the mandrel size the same and decreasing the wire gauge 2 sizes (example: using 22 ga. rather than 20 ga.), OR increasing the mandrel size when winding the wire for the loops.

It is also advantageous, when fusing links at 20 ga. (0.8mm) or larger, to flip the rings over and make sure the other side is fused as well when using Argentium. I have generally not found it necessary to do this for 22 ga. and smaller.

In short: I am increasingly fond of Argentium for fusing applications. For me, it's been both easier to use AND makes sturdier results than the same techniques in fine silver.

The worst downside- apart from but related to its lower melting point- is that Argentium is not especially compatible with enamels- another love of mine.
afmetalsmith: (cloisonne)
I think I am about to head into the studio and mess with my hex settings again. Yesterday I rolled out some silver really thin, and made wee shims to fill much of the gaps between the smaller and the larger telescoping tubing. As a proof of concept this worked great! but I'm concerned that I may have rolled the shims too thin, and so think I will try again with ones that resemble foil a bit less. One way or another, I should be able to solder up the test today or tomorrow, and we shall see if it solves the Mysterious Tubing Shrinking Problem! (I'm sure it will, but the tighter the shimming is, the better.)

Argentium: Also, I've heard back from some argentium experts, and it seems that the firescale was user error- though I did stump them for a bit! I'd soldered much of the pieces on a charcoal block... and while that is (according to many) a Good Thing for sterling in general, it's not for argentium. The germanium oxide coating that protects it relies on oxygen to create itself- and charcoal sucks up the O2 (which is normally ideal, since else it mixes with the copper and creates firescale) so the germanium has nothing to react with. Makes sense to me, and no more argentium on charcoal here! though now I need to find some other soft soldering block that I can pin into, to align pieces for soldering...
afmetalsmith: (Default)
J has suggested that I take a piece of argentium sterling and try to produce firescale on/in it. If I succeed, we can send it to J's dad's lab- he's a materials physicist, who specialized in metals (albeit mostly steel) for much of his professional life, and he ought to be able to figure out at least what happened, if not how it happened.

I'm excited about this!
afmetalsmith: (Default)
The first flush of my love for argentium has worn off. Yes, we've quarreled.

You see, one of the HUGE enticements of the stuff is "no firescale*!" And today, when I thought I was done with my crow scent lockets, I was adding the felt for the scents... and there was firescale. Oh, yes.

So I had the joy of firescale removal, on a metal I'd bought explicitly because it's supposed to be no firescale- and paid somewhat extra for, too.

I will say that the firescale was less deep and persistent than it is in normal sterling, so that's something. But still- it wasn't supposed to be there at all! And I can't figure out what happened.

I've posted a message on Orchid- a pretty high-traffic jeweler/metalsmith list- asking for input. It's possible that some copper got into the argentium via the pickle, I suppose- though my pickle's pretty clean, it's my usual pickle- which is not supposed to be a problem according to many people, though some recommend that one have separate pickle for argentium, and maybe they're right.

*For those less metals geeky- firescale is one of the plagues that afflicts us metalsmiths, especially those of us that work in sterling. Sterling is slightly porous in nature, and has copper in it. Copper reacts enthusiastically with oxygen, especially when hot. The end result is firescale: when the sterling is hot, oxygen reacts with the copper not just on the surface but down a ways into the metal, leaving blotches that look almost like bruises on the surface. And they are such that one often doesn't notice them until one has done all the polishing etc.- they're more visible in indirect light than direct, and so are hard to see under working conditions- and then one has to go back and abrade the surface until one gets past the firescale, and re-polish.


afmetalsmith: (Default)

September 2011

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