Kilns Tips
Read these 17 Kilns Tips tips to make your life smarter, better, faster and wiser. Each tip is approved by our Editors and created by expert writers so great we call them Gurus. LifeTips is the place to go when you need to know about Doll Making tips and hundreds of other topics.
Noises in The Kiln
When the kiln has turned off and you hear a lot of cracking noise, your doll parts are not breaking. The kiln has reached the tempature needed and the greenware is in the final stage of becoming porcelain. The noise is OK.
Firing A Kiln
Bisque firing can go as high as cone 6 or cone 7. It is better to purchase a kiln that will fire to a cone 10. If the kiln fires only to a cone 7, you will be firing it at maximum heat, putting more stress on the kiln and shortening its life.
Placing Arms and Legs
Arms and hands can be placed with the fingers pointing up if they will stand on end. If not, put sand or a piece of silica blanket under the parts of the limb that doesn't touch the kiln shelf. This helps to prevent sagging or the piece from becoming flat.
Loading Legs Into The Kiln
Legs can be tricky. If you can stand the leg with the feet up, place it in that position on the shelf. When placing the leg horizontal, you need to support the leg with a silica blanket or sand. Any part that will not touch the shelf needs support. You can use the shelf post covered with the silica blanket under the ankle. A silica blanket covered horizontal post on either side of the leg to form a "V" for the leg to rest in also helps prevent collapse.
Silica Sand
If silica sand is not available, an alternative is pure white sand. Toys R Us (the only place I have been able to find it) carries sandbox white sand. It is very pure and has almost no black specks and is veryfine. I use it all the time. Once I tried pool filter sand but it was neither fine nor pure and my pieces had sand imbedded in them. I had to throw a good bit of the load away.
Shoulderhead
Shoulderheads can be a problem in the kiln. Two weeks ago I had a waste shoulder/head, Pope John Paul II. Instead of putting it on a post, I turned it upside down like a dome head, leaning the back shoulderplate part against the kiln wall. Much to my delight, I had a perfect firing. I poured three more heads and tried it again with the same good results.
Plan Before Loading the Kiln
Planning how to prop a piece before you place it in the kiln will help prevent accidents in the kiln. I had a shoulderhead of Pope John Paul II I had placed over a padded post that was too short. When I lifted the shoulderhead off the post, the post fell over and broke several pieces that I had already put in the kiln.
Buying A Kiln
When buying a small kiln, look at the manufacturer's additional items you can purchase for the kiln. If you can buy an extra ring, will it have an element for heating the extra area? My first kiln was an Evenheat with inside measurements of 9x11 inches. I could fire a doll with arms to the wrist and legs to the ankle (Kitten), but not my llama. I purchased an extra 4" ring, which did not have any elements. The kiln would not fire to cone 6. The inside area was too large for the elements to reach the necessary temperature. Seven years later that kiln is still working and I'm glad I have it, but even happier that I also have a larger one.
Spacing for China Firing
When doing a china fire, put the pieces as close as you want. Unlike a bisque fire, the kiln isn't going to get hot enough to change the bisque so the pieces will not stick together.
Dome Heads
There are several ways to handle a dome head without causing it to collapse when firing to bisque. Set the head on its top. It can be held in place by using silica sand (follow precautions when using the silica sand), or silica prop. You can also use kiln shelf posts on its side with prop where the greenware stouches the post. This will hold up the head. By having the opening up, gasses and heat are allowed to escape without putting stress on the piece.
How Much To Use?
Use a small amount of sand on the shelf. Your goal is to provide a moving item between your piece and the shelf that will allow the piece to shrink without grabbing the shelf, which will cause breakage or malformed pieces.
Loading A Kiln
Leave ½-inch space between pieces. Closer than this the pieces may accidentally touch each other and fuse together.
Prop
Prop can be used to support your pieces during bisque fire. Do not pack tightly. Use loosly packed prop inside large pieces. I have always been told that if there is 5 inches of open space, you should put in prop. Too much prop could cause the piece to crack. So less is better when working with prop.
Loading Legs
When I fire legs, if they are not very steady on end, I often fire with the toes touching the side of the kiln. This gives the leg a little more support. I have never had them fuse to the walls. I would suggest you check with the manufacturer of your kiln, or try one leg.
Witness Cones
Use "witness cones" on the shelf to assure yourself that your firing went as expected.
Getting the Correct Head Start.
If a head has a flat opening on the top, put it into the kiln neck side up. This allows the heat to escape through the neck opening.
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