March 10th, 2007
|05:13 pm - Argentium woes|
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.
Hmm... would purposely introduced "firescale" by adding copper somehow result in a pleasingly mottled effect, or is it too random a thing to be creative with? (Bugger when you don't want it there, mind!)
It's both subtle and really random. It shows up best when you're doing a high polish- or certain kinds of matte finishes- where it's obvious a bug and not a feature. I've been trying to think of ways one might use it, but so far haven't had anything click; it's pretty random, and I'm sure if one wanted it it'd be nowhere to be seen! Metals are perverse that way. :)
Typical, the one place you don't want it to be, its there in abundance!
Personally, I blame the soldering demons. I really need to put up some sort of icon for them around my soldering area- a lot of metalsmiths have such!
that happened to me once recently actually - on the pin/necklace i made for my grandma. just a little blotch of it. it's the only time it's happened though, and i have no idea why.
I've studied with a lot of very experienced metalsmiths, and most of them have their own, no-fail firescale preventative... and in my experience, all of these probably work great for them, but are hardly universal.
And it's really flaky, too- using the same stock, and the same basic techniques- some pieces will be horrible and others pristine. Argh!