With my new home glass studio set up and ready for production, I launched into the Tint Tone Plate project included in my Bullseye Tech Notes binder. The Starter Kit that came with my BenchTop-16 kiln included all the glass needed to make two projects, and this Tint Tone Plate looked to be the easiest of them. Plus, it would give me the opportunity to hone my glass-cutting chops, which were rudimentary at best. I decided on the green-and-white plate, and began to follow the cutting instructions—with a twist. As it’s generally my nature to take a perfectly simple project and complicate it unnecessarily (just to make it more sporting), I decided to mix in some strips with ends cut on the diagonal, rather than the simpler straight strips shown in the project instructions. I also decided to use a strip of red iridescent glass in place of the clear strip indicated on the instructions, because I wanted more contrast in the finished plate.
Though I haven’t cut much glass, I have cut a great deal of paper, matboard, and other materials over my thirty-plus-year career as a graphic designer and artist. This gave me a bit of an edge (pun intended) when it came to working with the glass cutter, though it was still different enough in the hand from an X-acto knife for me to feel awkward with it. Once I got into the rhythm of measuring, marking, and cutting, that awkwardness faded away, and I quickly began to love the satisfying “tink” of glass breaking cleanly along the score. About forty-five minutes and several mis-cut strips of glass later, I had my little stack of pieces cleaned and ready for assembly.
I wanted minimal texture on my piece, so I opted to use a sheet of ThinFire paper between the glass and the shelf. This was described as an option in the text of the project, as using ThinFire prevents hot glass from picking up the brushed texture of the kiln-washed shelf. I’d been in Resource Center Santa Fe just the other day when a discussion about ThinFire paper came up between staffer Meredith and another patron. I overheard her explain that ThinFire can curl at the edges during firing, and that it was important to trim the paper close to the edge of the piece, so it wouldn’t curl up and touch the surface of the molten glass. A very helpful tip! As it turns out, there was more to using ThinFire than close trimming. But more on that later.
After arranging my glass strips in the kiln on top of the ThinFire and capping them with a second 9” x 9” solid glass layer, I punched in the firing schedule included on the project sheet and had the kiln clicking away in short order. When I cracked the kiln and peeked in the next morning, what greeted me appeared at first to be a perfectly fused flat panel. As I held the glass up to the light, however, I noticed a sort of haze across the entire top surface. What the…was I looking at devitrification? I didn’t think so, because I’d been obsessively careful about cleaning the solid top sheet before setting it on top of the cut strips. Plus, the haze was evenly distributed over the entire surface. It was very subtle; in certain light you couldn’t really even see it. But the glass didn’t have the crisp clarity I expected. What to do?
Because I’m fortunate to live only minutes away from the Resource Center, I bundled up my ailing plate and drove over. The discussion that ensued among the staff was really interesting: I found that—as with most technically complex forms of construction—there are multiple approaches that can be taken, and that there isn’t always universal agreement as to what is the best solution. As it turns out, my choice of ThinFire paper for this project wasn’t really ideal. It wasn’t wrong exactly, but because my kiln has such a small firing chamber, the byproducts generated by the ThinFire as it heated up became concentrated enough to leave a film on the top of my glass. OK, so I had the “why”—now what to do about it?
“Well, you could resurface the glass with loose grit and then fire polish it,” was one answer. I decided to try this, as I had practiced working with loose grinding medium in a Bullseye coldworking class, and wanted to see how it would work in this situation. Easy, right? I’d picked up a big sheet of quarter-inch float glass at the Habitat for Humanity ReStore (another fantastic deal on recycled material) to use as my grinding platform, just like I’d learned in the coldworking class. I had three jars of Silicon Carbide, in 220, 400, and 800 grits, and I knew how to use ‘em. What I didn’t anticipate was how physically difficult this very basic technique would turn out to be when grinding a 9” x 9” piece of glass.
Following the steps I’d learned in the workshop, I poured a small mound of 220 grit onto the middle of my glass grinding table and added a little water. I put my fused glass face-down on the wet grit slurry and began moving the piece through the grit in a sweeping figure-eight pattern. I rinsed it off a few minutes later…and could see virtually no difference. This didn’t bode well. Adding more elbow grease and many more minutes, I finally saw results: the entire surface of the glass was now opaque as if it had been sandblasted. Correction—almost the entire surface was opaque. There were a couple of depressions in the surface of the glass that the grit had not yet touched. Since my goal was to remove the surface, not to make it completely flat, I opted to hit the low spots using loose grit slurry combined with wet/dry sandpaper, a technique recommended in the book Coldworking Glass Without Machines by Paul Tarlow. (This is the definitive guide to manual coldworking, the way your grandpappy did it before electricity.) On hindsight, I should have read Coldworking Glass Without Upper Body Strength. By the time I had worked through all three grit grades, my arms were about to fall out of their sockets, and my hands were cramping. Forget going to the gym, manual coldworking gives you a great workout and something to show for it (besides ripped arms).
While the piece could probably have used a bit more grinding, I decided it was good enough for government work—and spent the next hour with the sprayer in my kitchen sink, trying to blast carbide grit out of tiny bubble pinholes on the surface. After the pinholes were clear, I thoroughly dried the glass with a can of compressed air (the same stuff you use to clean the crap out of a computer keyboard). Into the kiln it went for a round of fire polishing, which is just a fancy term for taking an already-fused piece back up to full-fuse temperature. The idea is that the surface will remelt and become completely smooth once again. This time I fired directly onto a kiln-washed shelf sans ThinFire.
The next day I held my breath as I opened the lid to find a sheet of fused glass that was not only crystal clear, that sucker was as smooth as Sinatra’s croon. I did a brief happy dance and set up the 10-inch slumping mold with my glass piece in the middle. One more firing (this time using the slumping schedule on the project sheet) and I was rewarded with an elegant, deceptively simple-looking square plate. I was glad that I changed it up a bit; the strip of red iridescent sheen added visual interest to what would otherwise have been a fairly monochromatic palette, and the diagonal lines added movement.
It was a helluva learning experience, and the whole project ended up being much more complicated than I anticipated—but that’s an inevitable part of any learning curve. That said, I thoroughly enjoyed almost every part of this project. The achy muscles I could do without. Now, please excuse me while I admire the reflection of my newly ripped arms in the glossy surface of my beautiful Tint Tone Plate.
Editor’s note: Guest blogger Lois Manno is a New Mexico-based writer, artist, and illustrator. She’s also a newcomer to kiln-glass who’s agreed share some of her adventures in her new medium here. She blogs about her art and other adventures – including cave exploration – at loismanno.com.
For more information on loose grit, see our video lesson Coldworking with Loose Grit (subscription required).