Cleaning Gluing the Glass, Firing the Glass

on the side of caution if you aren’t sure how long to anneal. Small projects such as earrings rarely need annealing time as they cool.

Cleaning and

Gluing the Glass

Grease, dirt, and fingerprints etch per- manently into the glass during firing. Clean the glass with glass cleaner (the type without silicones), rubbing alcohol, or even plain water just before assembling the pieces on the kiln shelf.

Use white glue, such as Elmer’s diluted 1:1 with water, to hold the glass pieces together after you place them on the kiln shelf. Use the glue sparingly. Glue is especially important

when fusing wire into the glass. The glue prevents the glass or wire from moving out of place before they fuse. The glue disappears during firing.

Avoid using glue on the coated side of dichroic glass. If you lay dichroic glass carefully onto the piece, glue is unnec- essary, so avoid it altogether if you do not know which side of the dichroic is coated.

Loading the Kiln

Air should circulate between the shelf and the bottom of the kiln, so place three or four 1/2” posts in the kiln. Lay the shelf over the posts.

Firing the Glass

1Vent kiln by opening the door ½” and leaving the vent hole (if your kiln has one) open. Venting allows the gases released to escape. When the kiln reaches 500 - 800° F / 260 - 426°C, close the door.

2The first time you fire a particular brand or type of glass, program the controller for a higher tempera-

Looking at the glass during firing. Open the door about ½”. Always wear firing safety glasses when looking at the hot glass.

ture than the estimated fusing temperature. Watch the glass by opening the door ½” for several seconds at a time. Shut the kiln off when the glass fuses the way you want. Make a note of the shut-off tempera- ture. For future firings, program the kiln for that temperature and rate.

Note: With every firing, be sure you are near the kiln before the expected shut-off time.

3After you shut the kiln off, vent the kiln for five min- utes by opening the door 1”. Then close the door.

Note: Some glass artists flash cool the glass after it fuses. They vent the kiln until the temperature drops to 1000° F. Then they close the door again. This speeds up cooling.

4The annealing range for most glasses is between 950°/510°C and 700°F/371°C. Cool slowly through this annealing range. Leaving the door closed will slow the cooling enough for most projects. If you need even slower cooling, program a separate seg- ment for cooling. See the kiln’s digital controller manual.

Note: For safest cooling, leave the ware inside the kiln until the kiln reaches room temperature. If you remove the ware too soon, the sudden temperature change can crack the piece.

To remove small pieces, such as glass jewelry, before they have cooled com- pletely, remove the shelf also. Leave the pieces on the shelf until they reach room temperature. The heat in the shelf will help prevent them from cooling too quickly.

Caution: Before removing a shelf, turn off power to the kiln.