This is my first slumping project. I’ve done a number of other glass pieces, but this is the first time I’ve used my kiln in this apartment, and I was thrilled to find out the breaker is rated to well over what this kiln requires.
Step 1: Materials and Supplies
A glass bottle, preferably the size of a wine or alcohol bottle, that will fit in your kiln
To get the glass bottle, either buy some alcohol and drink it (if you are of legal drinking age), or if you don’t drink enough (like me), ask your Facebook friends. Especially right after a holiday and before recycling day, when I asked, they are sure to have some bottles around. Or do what one of my friends suggested: ask at a bar or restaurant for empties.
My friend gave me this beautiful vodka bottle for my first try.
Step 2: Clean bottle thoroughly
Allow the bottle to dry inside. This may take a few days.
Step 3: Prepare the kiln
Depending on your kiln, you may or may not need to program it. For manual kilns, you will need to follow the steps outlined at http://www.glass-fusing-made-easy.com/slumping-bottles.html.
I have an older Jen-Ken AF3P (glass kiln with bead door). I believe the newer Orton controllers come pre-programmed with a Slump program, but mine did not. These are the steps I programmed my kiln to use:
Ra 1: 500 (degrees per hour to ramp at)
oF 1: 1100 (first stop for soaking)
Hld1: 0.10 (10 minutes soak time)
Ra 2: 250 (slow increase)
oF 2: 1425 (peak temp for slumping)
Hld2: 0.10 (hold, but skip if item has slumped already)
Ra 3: 1100 (crash cool; open kiln a crack to make this happen if possible)
oF 3: 1100 (stop at 1100)
Hld3: 0 (move on)
Ra 4: 150 (slowly cool off to room temp)
oF 4: 0
Hld : 0
Step 4: Prepare the bottle
If you’d like your tray to hang, cut a piece of 20-gauge wire a few inches long and bend it to fit inside the bottle top. The bottle will slump around the wire and hold it firm.
Step 5: Slump the bottle
Run your kiln program or manually slump your bottle.
My temp and cycle were too long and high for this glass, so I got extra melting. Keep good records of what happens to yours so you can improve your techniques over time.
The bottle will take a long time to cool. After it is cool, take it out, wash it, and use it in good health.
Don’t do what I did and rush the cooling cycle to meet a contest deadline. Mine cracked as a result. See the next step for how I rescued it.
Step 6: Added enhancements
You can buy and add self-stick rubber feet like these. You may be able to find them in craft stores.
UPDATE: I re-fired the kiln to soften the broken corner. It worked pretty well. I didn’t raise the heat all the way, so it would mostly keep its shape. I also added a piece of silver foil to the back, which turned golden on the inside (pretty!), and I added a few cubic zirconia for some sparkle. I love it!