Wednesday, October 28, 2009

Pulse bracelet construction worries

The things that gnaw at me in the middle of the night.

Reticulation silver has a more brittle temper, post-reticulation, than does sterling and definitely more so than copper. I have intended all along to rivet the reticulation strips to the copper wires prior to forming the cuff into, well, a cuff. How else am I going to do it? The wires have to be formed as a group. Sure, I could attempt to shape each wire and shape them each the same but that's not realistic. There will be differences from one wire to the next. And there are seven wires. In some contexts, this would not matter. But as I will be laying six strips across these seven wires and then riveting them all together, and as those joints will have no play in them, the differences will quickly become glaring and, I fear, insurmountable. Thus my decision to rivet first and then shape.

Pillage then burn.


Will the increased temper pose its own problems? Will one or more of these strips crack? Removing the rivets and replacing the strips will be difficult and I suspect I would damage one or more of the wires and possibly the nearby strips. How would I even get those rivets out? The only thing I can think of would be drilling them out and that would be nightware, even with the drill press. And what of the sterling wire rivets (I'm planning to use sterling wire at this time, would something else be better, I want my mommy) and the rivet holes? Will the rivets deform or crack even if the reticulation strips don't? Will the rivet holes get enlarged?

Why did I think this bracelet was a good idea?

I had toyed with the idea of backing the reticulation strips with sterling sheet (or copper) for stability and strength. I had set that idea aside. Now I revisit it. Should I back each reticulation strip (actually I would layer the piece, sterling strips, copper wires, reticulation strips) with a sterling strip and hope that it takes most of the stress? How can I decrease the stresses as I'm forming the cuff? Why did I want my mommy? She'd be no help at all.

Could I wrap each riveted joint with some sort of tape, perhaps the glassworker's best friend, electrical tape, to try to take up some of the stress? Wire would possibly cut into the various surfaces and mar them. I'm going to try that, I think, the electrical tape. It's flexible enough that I can get it into nooks and crannies but not likely to mar the surfaces.

At least I'll feel like I'm doing something.

The reticulation silver has been slow to deplete. I don't know why? Is it the bulk of the piece? But why would getting the piece up to a uniform temperature affect the formation of copper oxides. The rosebud tip is absolutely useless. Even the big, big torch is slower than I would expect. Holding the door of the kiln open from time to time to replenish the O2 is not helpful. Kiln depleting is still my fave rave idea, though, as I can work on other stuff while the oxides are forming. Read More!

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. Read More!

Random facts

My first word was pickle. This never made sense until I started working with metal. Now I wonder if I was referring to Sparex or citric acid. Alas, some questions will never be answered. Read More!