BEcon, finis

Apparently, I am 32, 6 foot 10, built like Morgan Le Fay (or maybe Wonder Woman) with waist-length coal-black hair and a princess conehead hat thingee. (think Frazzeta’s women) I walk around with a computer on my head and a chunk of glass in one hand while the other hand does tiny Queen-like wavelets to the populace. Or so folks meeting me at BEcon thought before the cold light of reality struck. (i.e., they met me)

They got the computer and the glass right, anyway.

This BEcon (i.e., Bullseye glass conference) was a showstopper in many ways, but the best part, as usual, wound up being the people I met and remet.There was as much sharing outside the conference as in, and I met a lot of generous people who were more than happy to clue me in on casting stuff I needed to know.

And here’s a tip for anybody who wants to hold a conference in Portland: Make sure you’re near a great farmers’ market on Saturday. I got to intersperse glasstuff with strolling the market, meeting new folk and snapping pics…and got to enjoy my favorite hand-cut Irish oatmeal with yogurt and mango chutney. Fresh goat cheese, pesto and a baguette for lunch, topped with fragrant raspberries.

Ahhhhhh.

So. Highlights of day 3:

Goodbye 960. Unless you’re living under a rock you already know Bullseye quietly announced here that it’s changing its defacto standard annealing tables. The recommended anneal soak temperature drops to 900F from 960F.

According to Ted Sawyer, who runs BE’s research and education department, the closer you get to the strain point of soda-lime glass, the less time you need to spend in anneal soak. Stress in the glass relaxes more quickly at 900 than it does at 960.

Shorter anneals are advantageous for folk who make a living with glass art, since it means they spend less time in production with every piece. It could shave 200 hours off the schedule for an 8-inch thick kilncast piece. And if the glass is cooling over a shorter temperature range, the risk of breaking may be less.

I asked when Bullseye would post the new tables online and was told they’re working on it.

UPDATE: The new thick annealing tables are now posted on the Bullseye site.

They also emphasized (strongly) that there’s nothing wrong with the old schedules. They can still be used.

Delta T is not a fraternity teeshirt. Ted and Australian artist/professor Richard Whiteley spent quite a bit of time on delta T annealing, recommending it wherever possible for casters (and Ted’s definition of casters was fairly broad). In delta T annealing, the goal is to ensure that the glass cools evenly throughout, i.e., stays pretty much the same temperature plus or minus 10 degreesF.

That means you monitor the kiln, glass and mold at different points during the cycle, and either adjust the kiln to equalize temperature or slow down the schedule to compensate. And this, in turn, means you’ve got more than one thermocouple in the kiln and, hopefully, some way of increasing or decreasing heat in different zones. Bottom elements become essential, at least for thick work.

Fascinating stuff, as was Whiteley’s discussion of the problems in annealing negative spaces. If you tack-fuse you’re (painfully) aware of the need to anneal a tack-fused piece longer than its flat-fused brother. Whiteley’s explanations brought the reasons into focus.

Quest for clarity. Whiteley detailed several tricks they use in Australia to clarify transparent glass castings. They’re especially careful to avoid potential outgassing or water vapor from the mold, which can leave veils, impede glass flow or exacerbate devit.

They open the kiln just after top temp to remove the empty glass reservoir. Then they torch the upper part of the glass in the mold to pop bubbles and finish off the work. Whiteley also discussed “sucker suck,” i.e., uneven shrinking of the cooling glass inside the mold, which tends to leave holes in the surface and is pretty much fixed with a hold around 1150F.

Local color. Last week’s BE class on glass color testing paid off; students helped demonstrate the mixing of multiple formats, thicknesses and colors of glass. Their castings (all 280 of them) were a great illustration of why pate de verre artists need to make so many color tests themselves.

There’s more (quite a bit more, actually–on color and light, artistic aesthetic) but this is getting long and I wanna go to bed. More tomorrow.

–cynthia

PS. If you want to read the whole BEcon report, here are the links:

• BEcon, Day 0.5
• BEcon, second day
• BEcon, finis (this post)
  
• Winding down a week of glass

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