Friday, October 16, 2009

Now What?

I guess I've been lucky in that I've never really seen much devitrification in my glass work. I think this piece has it - in spades. That is the problem, but first the background. I took Marty Kremer's workshop at Corning this summer. That was a great time and I learned a great deal. We did a lot of strip cutting to use in our work during the week. One of the other participants had some leftovers and gave me a dozen or so strips that were made with stringer and confetti. They were quite nice, but I never really knew what I was going to make with them.

I'd been playing with them in various configurations since early August. I was never quite happy. I had them laying around on the workbench and was complaining to my wife that I knew there was a great piece in the strips, but I was having a hard time finding it. As I laid several of the strips side by side, she remarked that it reminded her of the Native American fabric weavings. I knew what to do.

Rather than stack the strips vertically, laying them horizontally was the key. I put a strip of black iridized glass face down, then a strip of a color - in this case white, black, yellow, and orange were used, a strip of clear, and finally the magic stringer/confetti strip on top. This made 4 layers or about a half an inch thick blank. I was using a 12" diameter ring mold. This is where problem #1 starts. The first picture shows the set up in the kiln.

I have a small kiln at home. It is about 13.5" across, and its a weird 7 sided shape. I thought the
round kiln shelves were 13" in diameter. I set the ring down on the kiln shelf and it fit perfectly. However "perfect" in this case meant dropping down around the sides of the shelf and not sitting on it. Crap... I had a piece of fiber or vermiculite board that I'd intended as a kiln shelf but never used. This was gifted from a friend and I wasn't sure of the composition but decided to chop down the corners into a roughly septagonal shape (7 sides-ish). So far, so good. Note that the ring just fits on the shelf - the picture could lead you to believe that the piece is hanging off the left edge.

I laid up the strip construction staring across the diameter of the piece. This turned out to be a good idea. Soon I realized that I actually didn't have enough of the stringer/confetti strips to do the entire piece. In comes problem #2. I was about 4 long strips short. I decided to fill in with a solid color and used a turquoise color that matched some of the stringer color. Nice southwest feel. Finally I had the piece constructed and felt good about the blank.

Into the kiln and all went well. The next morning I opened the kiln and saw a couple of issues. First, the turquoise areas were distracting. The lines between the strips in the pattern area disappeared, but they were there in the turquoise. I
knew better. I could have used flat sheets in this area. But that wasn't the worst problem. The surface seemed to be covered with scum. I've never seen anything like it. I was stumped. I guess it is devitrification. But why. My current thinking is that there is something from the new kiln shelf/board that came out when it was fired. I later found out that the board was "new" and had never been fired. Are there some kind of binders that gassed off? Who knows.

The back is quite interesting - in fact, it may be more interesting than the front. These strips all came from the same sheet of Bullseye. I really haven't done much with iridized glass so wasn't expecting the "coats of many colors" look.

Anyway, my dilemma now is what to do with it. Getting rid of devit will require sandblasting and then fire-polishing - which I can do. Are there other things that could/should be considered. Should I cut off the turquoise and create an interesting shape when it is slumped? Or just turn it over and use the iridized surface?

Now what?

1 comment:

  1. I like the look of it. I would just sandblast it to get rid of the devit and fire-polish, then see what you have. The irid bottom will add another look to the back. go for it.