FRIDAY JANUARY 29, 2010
I had a successful Bisque Fire the other night! Here is a picture of my witness cones.
And here is the picture of the load all fired to bisque!
Once I was able to remove the parts, I had to sand them smooth. When you take porcelain bisque out of your kiln, it has a rough feel to it and you need to make it as smooth as silk. I have these 220 grit sanders that I use to smooth away all this rough stuff. Once I feel that I have it smooth enough, I will rinse the pieces under running water, let them dry, then take a piece of silk fabric and lightly run it over the pieces. If there are any rough spots on the piece, the silk will snag on it. These pieces have all been sanded and are now ready for the china painting process. China paint goes on your piece in layers. Each layer of paint also has to be fired onto the piece using a kiln and each head will have at least 4 coats of china paint on it since I paint the eyes. I have been after Gary for years to buy me a smaller kiln that I can use just for China Firing and next weekend, I am going to order one! At the present time I am still weighing out my options to see which kiln is going to be the most useful for what I need it for. The one I am leaning towards is a Cress Kiln. It is small enough that I will be able to china fire my heads and take them out of the kiln in less than 3 hours, but big enough that if I need to bisque fire a replacement part for a small doll, I can. I was looking at some other kilns that would not reach the appropriate temperature to bisque fire, but knowing that I am good at breaking those tiny little fingers off during my cleaning stage, I thought that a kiln that will fire at a higher temperature would be best. Once I recieve my new kiln I will post pictures.
Wednesday January 27, 2010
Making Porcelain Dolls is a fun, exciting, fulfilling and expensive craft. When you start making dolls, you learn very quickly that a kiln is the most important and essential tool you will need. While working on Molly's new Smocked Dress, I decided it was time for a little Kiln Maintenance. Anyone who owns a kiln knows what I am talking about when I say "Kiln Wash". This is protective coating for your kiln shelves and floor that you need to paint on your shelves. It comes in a powder form that you need to mix with water to a thin cream consistency. After a few bisque firings, the wash begins to crack and peel off the shelves, so new wash has to be applied...however, before the new wash goes on, all the old has to be removed. This can be a grueling process and luckily, Gary was here to save the day and scrape the old wash off for me ;) Last night I applied the first layer of wash and today, I applied a second coat. The wash gets put on in layers and dried completely between layers...and you paint each coat on in different directions (eg. up and down 1st coat, side to side 2nd coat). I have been given many different instructions on how many coats to use, but I have found that for my kiln, 2 coats are sufficient. Here is a picture of my shelves with the new wash on. You can see the dark spots where the wash is not completely dry yet. As soon as this coat is completely dry, I will be able to set them back in my kiln and set it up for Bisque Firing!
Here is a picture of some soft fired greenware that I have ready to bisque fire.
This ware will go into the kiln where it will undergo a process called vetrification. When I set up my kiln, I will place cones, known as Witness Cones on the shelves and a smaller cone on the kiln sitter. This small cone (cone 6) will melt and bend at a certain temperature and will automatically shut the kiln down. The witness cones are used to make sure the kiln fired at the correct temperature. I will put a cone 5, 6 and 7 on the shelves and when I open the kiln, I will inspect these cones. The cone 5 should be bent all the way over, the cone 6 will be bent half way over and cone 7 should only be slightly bent. Here is a good picture of what the Witness Cones will look like if my kiln fires to the correct temp.
I will also place a thin layer of silica sand on the shelves so that when vetrification is occuring, the pieces can move around on the sand. This is a very fine sand that allows the pieces to move and shift without pitting the porcelain. You see, during vetrification, the porcelain turns to like a thin taffy and If I were to just place the ware directly on the shelves, even though they are washed, the porcelain would still fuse itself to the shelf ruining not only the piece, but the shelf as well. During this firing, the inside temperature of the kiln will reach approx. 2230 degrees farenheit...now that is HOT HOT HOT!!! It will take about 8 1/2 to 9 hours for my kiln to reach this temperature and I will have to leave the kiln to cool naturally before I can open it to inspect my ware. When I fire this greenware, I will set my kiln to low for 1 hour with the lid propped open and the peep holes open. After an hour, I will bump the kiln up to medium and close 2 of the peepholes and close the lid. After another hour, the kiln goes to high and I will close up the last peephole. From there on, the kiln does all the work. About 6 to 7 hours later, the cone on the shelf sitter will bend and the kiln will shut down. I never leave my kiln unattended when bisque firing. If the kiln has fired over the time it normally takes, I will only let it fire for about another half hour and I will manually shut it down.
If all goes well during the bisque firing process, by this time tomorrow, I will be able to post pics of the fired bisque!