Friday, October 9, 2009

Pulse bracelet update

I've put the reticulation silver through several rounds of depletion silvering in the kiln. The first time, a few Sundays back, I hauled it out with a goodly layer of nice, charcoal gray oxide coating it. Tried quenching it directly into the crockpot—experience is a great teacher. After I rinsed out my dress and mopped pickle off the floor, I moved the crock back to its usual spot. A bit of the oxide came off into the pickle and then the process seemed to stop. The sheet maintained a sooty, coppery look, very coppery. The pickle did not get particularly blue. After a bunch of time, I pulled the sheet out. Turned out the firescale was just sitting there loose on the surface and came off with some rather lackadaisical rubbing, most of it anyway. Since then, however, the sheet has only taken on a mild haze whenever I put it in the kiln. I have wondered if the oxygen level is too low to support good firescale production. What, then, explains the first time with the lovely charcoal gray? Could it be that the available oxygen was enough for the more surface copper molecules but not enough for anything deeper?

I can't believe that the initial pass would have created such a thick layer of fine silver so that no appreciable amount of copper can get through anymore.

Pat has suggested removing the thermocouple to allow more oxygen into the kiln. This scares me. I'm afraid the temperature will rise to dangerous levels and my silver will either turn into a worthless, molten mass or that some sort of heat hardened temper will make the thing unusable. (Since I'll only be cutting the sheet into strips, at least that's all I have planned for it so far, and won't be shaping it, does temper matter? Can reticulation silver reach a state of such brittleness that it would snap with any use? On reflection, that's a silly question. Duh! Of course it can but under what circumstances?) I could leave the thermocouple in and maintain a decent temperature until I'm ready to throw in the sheet, only removing the thermocouple when I'm there to monitor the process and for limited amounts of time. Temperature does not rise that quickly inside the kiln.

I'll use the big torch this Wednesday. If I go in on Monday to trouble the fabrication toddlers, I'll try the rosebud. Oxygen will not be an issue under those circumstances. I can even boost the O2 to speed the process. Prepping metal for reticulation is just about the only instance I can think of when you want an oxidizing flame when working metal. (I wonder if enamels can react differently to reducing and oxidizing environments? That would be something interesting to explore.)

It's highly unlikely I'll manage to get in this weekend to work; temps are supposed to reach an easy ninety degrees. With the A/C turned off on the weekends, there's no way I could work in there except for an hour or two, and that's if I get there smack-dab at eight in the morning.

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