Elmer's Glass Kiln manual Lost Wax Burnout, Overview, Sample Program, Cone

Open the door ½” to vent the kiln if your kiln does not have vent holes.

China paints will crack or peel if ap- plied heavily. Apply several light coats in- stead, firing between each, until you get the shade you want. Not all china paint colors reach maximum color saturation at the same temperature even when fired on the same ware. So you must know which col- ors you should fire first at higher tem-

peratures to prevent burning out the original colors in later firings. For example, reds mature at a lower temperature than other colors and are fired after the other colors have been fired. Reds and yellows should not be fired side by side. Colors also mature at a lower temperature on ceramic pieces than on porcelain or hard china. Check the overglaze manu- facturer’s literature for information on which cone to use with each color and type of ware.

Vent the door during the first hour of firing. If your kiln has a vent hole, leave it open during the entire firing. Allow kiln to cool to room temperature before opening the door.

Temperature Equivalents For Orton Self-Supporting Pyrometric Cones

				Cone
Cone	Self-Supporting Cones			Pre-Fire
Number				Color
Heated at:	27° F	108° F	270° F
	Per Hour*	Per Hour*	Per Hour*
022	—	1087	1094	Green
021	—	1112	1143	Fuschia
020	—	1159	1180	Orange
019	1213	1252	1283	Yellow
018	1267	1319	1353	White
017	1301	1360	1405	Pink
016	1368	1422	1465	Light Blue
015	1382	1456	1504	Violet
014	1395	1485	1540	Gray
013	1485	1539	1582	Green
012	1549	1582	1620	Fuschia

*Rate of temperature increase during last 90 - 120 minutes of firing. Tables by courtesy of the Edward Orton, Jr. Ceramic Foundation.

Lost Wax Burnout

Caution: Only kilns with vent holes are designed for lost wax burnout. However, you can use a kiln without the vent hole provided that you open the door ½” during venting.

Caution: Always use a wax tray.

Caution: If your kiln’s heating element is embed- ded in the floor of the firing chamber, place the metal wax tray on 3 or 4 - ½” posts inside the kiln. This prevents the element from possibly shorting out against the tray.

Note: These instructions apply to injection wax that melts at 200°F, not pattern waxes and plastics that melt at higher temperatures. If smoke appears dur- ing wax elimination, turn off the kiln. Smoking wax means the kiln fired hotter than 300°/148°C.

Overview

Lost wax casting is the process of carving a shape in wax , and then casting that shape in metal. After the wax has been carved, a mold is made of the wax shape. The mold is a nega- tive image of the wax. The wax is later melted out of the mold through hollow channels called sprues.

Lost wax burnout is the process of preparing a casting mold for the melted metal that will be poured into it. The steps in lost wax burnout:

1Melt the wax from the mold.

2Remove wax from the kiln before raising the tem- perature higher than 300°F/148°C.

3Harden the mold at high temperature.

4Maintain the mold at the casting temperature rec- ommended for the type of metal that will be poured into the mold.

Caution: Prevent wax or carbon from contacting the kiln’s walls and elements. Carbon build-up in- side a kiln ruins the interior. Carbon conducts elec- tricity and causes elements to short circuit. Damage to elements from contact with foreign materials is not covered by warranty.

A Sample Program

See your digital controller instruction manual to enter this program:

	Rate	Temp.
Segment	°F/°C	°F/°C	Hold
1	500/277	300/148	01.00
2	500/277	1350/732	01.00
3	450/250	800/426	02.00

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