Wednesday, March 25, 2009
Fused Glass Pendants Tutorial
a prepared kiln shelf
glass-tac or Elmers glue
a digitally controlled kiln
For this tutorial I will be discussing how to make simple glass cabochons.
Selecting your glass:Not all glass is the same. Glass has what is called a COE (coefficient of expansion) number. It is important to know the COE number if you plan on mixing brands of glass. For this tutorial and my own preferred method is to use glass all by one company. You may be asking well what happens if I mix COE numbers. Sadly, the answer is is that your items will crack and break.
Now in glass you have lots of options: sheet, stringers (think spaghetti), frit (small bits of crushed glass), powdered, and confetti. For this example I am using just sheet glass. I prefer double rolled fusible tested glass from Bullseye Glass in Portland Oregon. If you live near Portland, stop in at the resource center for fun shopping and any advice you may need. They ship worldwide.
Select your glass colors. Opaque or transparent is strictly up to you. I have used opaque in these pictures.
Prepping: You will need to prepare a kiln shelf with kiln wash or shelf primer. Follow the manufacturers directions on preparing your shelves. Never ever fire directly on your kilns floor. The kiln wash or shelf primer is like non-stick spray for your kiln shelves. If you don't use it; all your glass pieces will stick to the shelf and be a waste. There is also fiber paper which is one time use and can be used in place of kiln wash. I find a well prepared shelf will go through several firings before needing to be redone with new kiln wash.
Cutting Glass:So you have selected your glass and now you need to cut it. For these pendants I used rectangles or squares which are super simple to cut. I just use a glass cutter I bought at my local hardware store. You cannot just cut a square out of your glass. You must first cut a strip of glass whatever width you want. This strip will be as long as your sheet of glass is. Score with your glass cutter whatever the width is. I like for pendants between 1-2" for width. If you don't think you can score a straight line use a sharpie to mark your glass with. Using your glass cutter firmly score in one movement. To break simple turn over and tap along the score line. You should now have a strip of glass. be careful not to cut yourself when handling the cut glass. Now figure out the length for your pendant. score your strip to however long your pendant will be and break as before. Now, you should have your base shape.
Assembly:Now you can use other strips and squares of sheet glass cut the same way as before but in different sizes to stack on to your base. Use a bit of glass-tac or elmers glue to help hold them in place. I often like to use frit or confetti sandwiched between two pieces of sheet glass cut to the same size. Both sheets can be clear or the bottom piece can be opaque. whatever your desire is feel free to do. Just remember where the glass touches another piece it will fuse. You may want to clean your piece of glass before you assemble them. This will remove any dust or fingerprints. I just use a soft cloth and windex.
The Kiln: Well, hopefully by now you have enough pieces that you are ready to fire them. Place them on your prepared kiln shelf leaving space in between each one. Each kiln is different. The following instructions work for me but they might now work for you. Check with your kiln instructions or find out from a glass fusing resource a schedule that works for you. Your items will go into the kiln at room temp. I ramp mine up at 10 degrees F per minute so 600 degrees per hour. I find that for me a full fuse is at 1500 degrees and held there for 20-25 minutes. I then have my kiln ramp down at 300 degrees per hour to 950 degrees and I have it soak there for a bit and then cool to room temp.
Annealing: so you might be wondering what is annealing. Annealing is making sure the glass is moved slowly through the brittle zone or temps known to cause thermal shock. If glass is cooled too fast it will crack and break. By allowing it to cool slowly the stress is kept to minimum. That is why I have my kiln slowly cool down to 950 and then allow it to cool to room temp on its own. When I first started fusing I often would come back to a piece weeks later only to find that it had broken and this was due to improper annealing. you can never anneal too long or too slowly. the bigger the piece the more time it will need to be annealed.
Now What?:By now your kiln should be cool and you can remove your pieces. You might find that some of your kiln wash has stuck to the back of your piece. This should wash away easily. At this point you can to decide what to do with them. As I am showing pendants the choices are to drill a hole (something I have never done myself), wire wrap, bezel set, or glue on a bail. The choice is yours. Have fun!
For supplies including glass, kilns and more check out Bullseye Glass