Molded Glass Candy Bowl
Project by Ann Hammer from Portland, Ore.
Materials and Tools:
at least 10" x 10" of 3mm Bullseye mint-colored glass
at least 10" x 10" of 3mm clear glass
lots of 1mm Bullseye rose-brown transparent stringer glass sticks, sold in tubes
circle cutter for glass
very wet sponge on a saucer
kiln wash/fiber paper/thinfire paper
ceramic bowl slumping mold
glass grinder or sickle stone (optional, often available to rent from stained glass shops)
devitrification spray or access to a sandblaster (optional and probably not even necessary, but often available to rent from stained glass shops)
1. Measure and cut out one 9-1/2" circle of opaque mint green glass. Use pliers to break away all the glass that is not in your circle. Save the scraps for other projects, including mosaic.
2. Measure and cut out one 9-1/2" circle of clear glass. Grind off any bits that may stick out after breaking off the edges of the circles. Note: When it's molten, this glass seeks to always be 6mm thick, so use two layers of 3mm glass that is tested compatible. If less than 6mm is used, the edges tend to creep inward and roll, distorting the design.
3. Light a candle that has never been used before, so that there is no ledge around the flame. Wet a sponge and set it, sopping, nearby on a saucer.
4. With clean hands, take out a short bit of transparent brown 1mm stringer glass. Holding it on both sides about 2" apart, hold the stringer in the flame at the hottest point. Apply very gentle pressure (otherwise the stringer will snap, and some must be sacrificed in the learning process) until the glass begins to give. Make a gentle 90-degree curve.
5. Let the glass cool, about a minute. Wipe any blackness onto the sponge, very gently, also cooling it. If this is done too soon, the glass may shatter.
6. Pick another place to make another curve, fingers 1" away on either side. Make each curve an inch apart to form a square. Try to keep the thing from twisting so they will sit reasonably flat in the kiln. Joining the ends in the corner looks more seamless than the mid-span joins.
7. With pliers or mosaic nippers, clip the first curve right as it opens up. Make the final curve to make the square, trying to join the first curve. Trim off any extra stringer and melt the joint together. If it won't join easily, leave it. Otherwise the glass tries to ball up and will look lumpy.
8. Make all the other squares. Keep the ones that break because they can be used on the edges.
9. Take an 18" long piece of stringer and measure how big the "surround" lines need to be to wrap around the squares. In this design, it's roughly 1-1/2". The surrounds cut in under and over each square 1/2". Melt the surrounds, measuring against finished squares and other surrounds. Don't trim any of the extra stringer that extends from the bowl area. Make sure it extends 1/4" off the edge of the bowl area.
10. Prime the kiln shelf or lay down thinfire paper. Clean the green and clear discs with dish soap and hot water. Place the green one textured side up on the kiln shelf. Place the clear one textured side down, so that the two textured sides of the two pieces are together. This will trap as many bubbles as possible.
11. Gently clean the brown stringer pieces with ammonia-free glass cleaner and lint-free cloth. Replace all the ones that break.
12. Start by arranging the longest center "surround" pieces on the green and clear circle. Fit in squares, then fit around the surrounds, until you've reached the edge of the circle. Let all the extra stringer extend past the circle that will be your bowl. This will be nipped off after this first firing, and it will keep the lines extending down the edges of the bowl so it looks good from the side.
13. Fire to fuse temperature (1450 F degrees) for 30 minutes. This takes 5 to 6 hours for the kiln and 5 to 8 more hours to cool to room temperature.
14. When the kiln reaches room temp, take out the patty. Nip off all the brown bits that extend off of the circle. Grind at an angle so the brown bits can still fall to the edge of the patty when it's fired again.
15. Clean the patty again. Scrub off any bits of thinfire paper or shelf wash that may get stuck to the back. If a matte finish appeared on the top of the piece, apply devitrification spray. This will restore the glossy glass finish (caused by the metals that color the glass floating to the surface and starting to crystallize — a common problem when glass is taken over 1300 F degrees). I usually only get devitrification when I've fired a piece more than once over 1300 F, or when I have opaque glasses on the top of my design.
16. Fire to fire-polish temp (at least 1375 F degrees) for 30 minutes. Dispose of thinfire dust wearing dust mask.
17. When the kiln reaches room temperature again, clean the patty and check for devitrification (meaning another firing with the devitrification spray). Here's when I sign my pieces with liquid gold or platinum ink and a quill-tip pen. The ink binder fires off, leaving metal that is fused to the glass.
18. Apply kiln wash to the bowl mold and dry in the kiln or oven (usually done beforehand). Put the mold in the kiln, wash hands, and lower the clean patty onto the mold, centering it and not smearing the ink.
19. Fire to slump temp (1250 F degrees) for 30 minutes. Going a longer time in this mold tends to make the center bubble up and the bowl a little wobbly. Going shorter makes it have a rounded bottom and be really tippy.
Web site: www.annhammerglass.com