Discover a unique take on glass feathering encasing the colors inside (instead of outside) a glass sculpture.
Glass artist Michael Rozell of Columbus, Ohio, demonstrates how to give glass feathering, a traditional Roman technique, a modern spin – he encases the pulls of color inside his glass sculptures. Basic glassblowing techniques, knowledge and tools are necessary for this project.
1. Gather 2150 degree F glass onto a blowpipe. Shape the glass with a wet cherry wood block. Repeat for consecutive gathers (Image 1).
2. Blow a small bubble and then apply preheated dichroic glass. Roll the hot bubble over it as it sits on a metal hot plate heated by a blowtorch (Image 2).
3. Heat this in a glory hole (a ceramic-and-metal barrel heated to 2000 degrees F) and blow out large and thin. When reheated, the bubble will collapse on itself, crumpling like paper. As this cools, gather more glass over the surface. All of the ridges and dimples of the crumpled bubble will trap dramatic air bubbles.
4. Add a jack line by squeezing down on the glass where it meets the blowpipe with a jack tool. (A jack tool is roughly 9-inches long, with two flat blades that align opposite each other.) Squeeze the glass between these blades to create a waist (jack line).
5. On a separate metal rod called a punty, gather a small amount of glass and attach to the bottom of the first piece. The blowpipe and punty form a straight line with the glass between them.
6. Place a drop of water is on the jack line. Break the piece free of the original blowpipe with a pair of large tweezers.
7. Gather additional glass so that the interior bubble design appears to be floating and surrounded by clear glass.
8. Wrap trails of color down the piece. Heated and shape bits of solid color, that have been preheated in an annealing oven, on thin metal punties. Wrap these five-feet long metal colored punties around the glass (Image 1).
9. Feed the color onto the glass piece by touching the hot color to the bullet-shaped glass on the original punty (Image 2).
10. Heat the glass and use a metal pick to rake the glass into a feathered pattern. This is similar to using a knife when creating swirl stripes of icing onto a cake.
11. Attach a separate punty with a hot glass bit on the bottom and apply water to a jack line to detach it from the first metal rod. Again, the design is floating and the axis of the piece is changed. Gather more glass.
12. Using a wooden block and a mitt made from wet newspaper, shape the final sculpture. The piece may also be shaped on a marver, a metal table. Roll the glass sculpture on the flat surface of the marver to shape and cool the glass. Squeeze down a final jack line.
13. Cool the piece to 1000 degrees F and drop water onto the jack line. Strike the metal punty with a heavy piece of wood so that the sculpture detaches from the rod. Rest the sculpture on a sheet of white fiber frax insulation, which will not stick to the glass.
14. Suit up in long Kevlar gloves and a face shield. With the protective gloves, pick the piece up and place into an annealing oven, which is holding at 900 degrees F. Allow the glass to cool to room temperature over a 24-hour period.
15. The glass sculpture is finished, but must be ground and polished to stand properly.
- Grind and polish the sculpture on a succession of diamond embedded pads. These magnetic pads are two feet in diameter and rest on a metal flat wheel.
- As the wheel spins, add water to lubricate the diamonds.
- The glass will need to be ground first on a coarse 80-grit wheel, then a 220-grit, all the way up to 675-grit.
- The last wheel is felt, to which cerium is added. This will polish the bottom to a clear finish.
16. Sign the feathered glass sculpture with a diamond Dremel bit.