Pouring

I took a class on pouring ceramics last week and I went a little crazy pouring lots of things. I went back today and cleaned up the items and poured a few more things. Mook was bored so he read and took pictures. I thought I would share a rough step by step of how pouring works.

The first image is pouring slip from a plastic jug into a bucket. I had to do this to make sure the slip is mixed properly before pouring. I took a paint stick and stirred the bucket afterward. I couldn't resist making the "bubble, bubble, toil and trouble" joke as I did it.

The next step is cleaning out the plaster molds to remove old clay, then using straps to secure the mold pieces together. In the second picture, I poured the slip from the bucket into the molds. You can see the full molds in the third picture. During this step you must make sure to pour the mold full. If you stop pouring and begin again it leaves a line in the piece.

After waiting 5-10 minutes you test the mold by using a tool to determine how thick the partially dried wall of clay is. When it is thick enough, you pour the excess clay out, as in the fourth picture. You then leave the mold on the bucket, using a grate to hold it up so it can fully drain. After another ten minutes you check the mold, when it is dry enough, you take the mold apart. This step takes the longest time as you have to wait until the clay decides it is ready to come out, time is less relevant than the size of the piece and the thickness of the walls.

You can see pieces in the partially opened molds in the next three images. After giving it another 10 minutes or so, you can then gently take the form out of the mold and trim off the excess clay. Allow the pieces to dry completely, trim any additional bits off and smooth the edges with a scrubber pad and you're ready to fire.





Needless to say, it takes a couple of hours to pour, a day to dry, another bit of time to clean up the pieces. Then firing usually takes 12-24 hours, a few hours to heat up, a few hours in the kiln and 8-12 to cool down. Once the item is fired, you can paint it with acrylics as decoration or with glaze which usually makes it food safe, but requires another round in the kiln to set. An interesting thing about ceramic glaze is that it is made of sillica, which is effectually glass. The reason it is food safe is because you are basically melting glass over the pottery, making it stronger, waterproof and less able to hold nasty bits in the pores like clay would.

The last images are of the pieces I made while taking the class last week, before they were cleaned up. They are mostly cups and pitchers with a few figurines thrown in. One of the cups has a partial lid which makes absolutely no sense to me at all. If you have ever seen a cup like this before and know why it has this piece, let me know. I am really curious. By the way, it's not a creamer or pouring device of any kind, there is no hole or spout.