Glass is stacked in the kiln in a random-ish fashion, with plenty of open space for it to flow once heated. This goes into the kiln for 15 hours, and reaches a temperature of 1470 degrees. You have no idea how this will turn out. You just have to go with the flow! (get it?)
When the kiln cools, the flow slab is ready to remove. It's a big ol' chunk of glass at this point, and needs to go to the wet saw.
After the wet saw, you end up with cross section slices of the slab, which are called Pattern Bars (for obvious reasons...)
Pattern bars can be used in a variety of ways. They can be incorporated into larger pieces, or sliced into smaller pieces for jewelry. When making jewelry, I typically stack part of a pattern bar with 1 to 4 layers of clear glass (depending on how large I want the piece, and how much I want the pattern to stretch) These stacks go back into the kiln for another 15 hour fuse. They emerge as "cabachons" (which is a more concise way to say "a shaped piece of fired glass with a flat reverse side")
Unless you are very lucky and end up with a perfectly shaped cabachon, you need to grind it to get rid of any weird bumps. (um, not "weird bumps", just "unwanted features") After grinding and sanding, the edges are no longer smooth. The piece must go back into the kiln for a 3rd time for about 7 hours, to fire polish it.
Once the shaping and fire polish are completed, it's ready to become a pendant (or earring, or bracelet, etc)! And I rejoice!
"Luke. I am yorh FAH-thuh" Safety first when working with glass powders! Nasty to inhale, because glass is heavy (compared to say, dust) and likes to settle in your lungs.
I add a few spoonfuls of the glass powder to a cup then pour in a little distilled water. After a stir with the popsicle stick, a slushy slurry is born!
Here I have laid out a variety of blues and lavender, mixed with French vanilla and white. I know that the French vanilla will have a chemical reaction with some of the blues, which will give some nice contrasting lines! I drag a knife (or sometimes another pointy object) through the powders to mingle the colors.
Out of the kiln after a full fuse to 1480 degrees. After exposure to high heat, some colors turn darker (the glass world term for these are "strikers". Maybe they are really good bowlers), so you have to research if you want to know what the final color will be. Or just wing it and hope for the best if you're feelin' lucky!
I mark out sections on the glass pieces that I think will make a nice shape and design for a particular piece of jewelry - a pendant, bracelet, or earrings. Then I cut out the sections, and further shape it with tile nippers. This helps to cut down on the amount of glass I have to grind - and saves me from having to replace that diamond coated grinder bit too often!
Here I decided to combine a piece of the painted glass with a solid coordinating glass. I cut a piece of white and placed it on edge, to separate the two, for added interest.
After the 2nd firing! You can see that most pieces don't come out ready to be jewelry - I have to cut them down further and grind them into a final shape. Lots and lots of grinding.
These have been shaped and are ready for their final fire polish. Here you can see the ground edges, which are rough.
After the final firing, the pieces are ready to move to the bail mounting station (aka, my kitchen table) The bails are glued to the glass, and then have to cure for 24 hours before they are finally ready for official blinging!
Some glasses will react when they come into contact with each other. This is due to the substances in the glass that create the color. For example, the sulfur in French vanilla will react with the copper in Steel Blue (and many other blues). Where the two contact each other, a brown border will be visible. There are a lot of ways glass reactions can be used for designing jewelry and other glass pieces. For this reaction pendant, I created partial sheets using a base glass with a reactive frit (crushed glass) on top
Fire in the kiln to 1470 degrees to fuse the frit to the base glass. A full fuse schedule typically runs for 15 hours. It will be another 4 or 5 hours until the glass in the kiln cools down enough to touch it.
The glass contracts because it is only one layer of 3mm, and left up to its own devices, glass really wants to be 6mm thick. When trying to double its thickness, the glass pulls in, but can't quite make it to 6mm for the entire piece. The edges end up being thicker and the middle is thinner. This typically makes the edges unusable because of the uneven slope. SCIENCE!
For this piece, after trimming the edges off and washing it, I cut small square pieces (about 3/4") from the part sheet. I then sandwich with 2 pieces of clear on bottom and 2 on top, trying not to topple the stack before closing the kiln lid (and cursing each time I knock it over). This stack of 5 pieces of 3mm glass, when fused, will emerge as a large circle, again trying to get to that 6mm thickness. More science!
After another 15-hour full fuse, the glass is circular, but might still have some rough edges. And by "might", I mean "always".
The rough cabachon is worked on the grinder to shape and smooth out edges. After it has been sanded, it will go into the kiln for a 3rd time, for about 7 hours, to fire polish it back to a glossy finish. A bail is mounted and it's finally a pendant! And I rejoice!
Glass powder is finely crushed glass, which may seem obvious, but it doesn't look like your typical piece of glass. I have to wear a dust mask to make sure not to inhale it (safety first! Or at least third.) For this technique, I sprinkle powder in various colors onto a special material called frax. Frax doesn't burn up in the kiln like other materials, and it doesn't fuse to the glass, so it can be removed after fusing. Once the powder is laid out about 1/4" thick, I spritz it with water to dampen it. After it sits for about 20 minutes, I carefully bend the frax so that cracks are formed. It looks a lot like a mostly dried up mud puddle.
The frax with the cracked powder goes into the kiln for a full fuse at 1470 degrees. When it comes out, little pools of glass have formed. The size will depend on how many cracks there are, since the glass pulls together where it touches.
So now you have little pools of glass that need to be attached to something. Like, I don't know, perhaps a sheet of glass? Seems logical. I place a solid piece of glass on top, then fuse it a second time. When it comes out of the kiln, the frax is removed. It's still rough on the bottom and edges due to the texture of the frax (I like to call these the Shards of Death. If you accidentally spear your finger on one, you will understand why. You will also understand why band-aids have a spot on my shelves. Lots and lots of band-aids.) The edges need grinding to make them Bumps of Tolerance. (These are not technical terms). A clear piece of glass is placed on top, to cap it.
The capped piece is placed into the kiln for a third full fuse. If you're keeping count, we are now at day 3...
When the glass comes out this time, its nice and smooooth (Bumps of Tolerance are mostly gone) On this particular piece, the powder was French Vanilla and the glass was Egyptian Blue. These colors react with each other chemically, and where they touch you can see feint dark outlines. Air also became trapped between the glass, which forms happy little bubbles. Unless you are going for no bubbles. Then they are sad little bubbles.
Once you have a solid piece of glass, you can use a mold to create something other than a flat piece of glass. For this one, I placed the glass on top of a mold (which I made from a stainless steel cocktail shaker purchased from Amazon, then coated with glass separator and turned upside down. Even prepping the molds takes a lot of time!) This gets fired at a lower and slower schedule, so that the glass melts down over the mold (called "slumping". As opposed to "slouching", which is very bad for your posture)
During the slumping process over the mold to form a vase, the glass has stretched due to it's weight. See how the glass pools have elongated when compared to the previous picture. It actually stretched more than I anticipated, and the mold was almost trapped inside! Now that would be one fancy cocktail shaker!
The glass can also be cut up into smaller pieces and fashioned into jewelry. Which requires a few more firings to get it formed and polished. These pendants took a total of 5 fuses! Crikey!