Building Blocks

This past week has been a busy one for the ceramics students of FUA. On Monday we started slip-casting the geometric shapes for Andrea's project... and it ended up being a lot harder than I had anticipated! We were warned that our first batch would be our worst, and I believe it. These pieces need to be perfect, so making a mistake in any of the steps from slip to kiln usually means that the piece cannot be used. I am eager to see if everything goes more smoothly in class tomorrow (now that we have tried everything once already).

Here are a bunch of pictures that Professore Raimondo took of our first attempts at slip-casting. I will do my best to use the pictures to explain the process...

These are the plaster molds we are using to create each little piece. They come in many different shapes and can most easily be filled by using a small plastic cup to pour the slip.

The slip first had to be strained through a wire mesh to prevent any dry chunks from ruining the pieces.

Simply gorgeous.

We carefully--and sometimes not so carefully--filled many of the molds with slip. The molds wrapped with black rubber bands (made from bicycle tubes) are two-piece molds.

Yeah! Slip-casting can be fun!

As the slip dries and shrinks a little bit, the center of each piece sinks in slightly. Additional slip must then be added to the concavity that forms before the first pouring dries enough to form layers. 

A little more can be added here.

Oh dear, someone forgot to keep an eye on these.

When the slip has dried (leather hard) and is no longer runny, we use razor blades to scrape the excess off. The two-piece molds can also be opened up soon after this time; since they are slightly longer they usually take slightly to dry. 

This stage in the process is also helping me quickly develop a hatred for plaster. I do not like the feel of it in my hands, and any flakes that are scraped off by the razor blades are potentially dangerous to the firing process. It is a good reason to be careful. 

We filled a lot of molds that day. 

After scraping off the excess. Some pieces come out easily, others need to be coaxed.

Another important step, putting a hole in the "bottom" of the piece, is most easily carried out while they are still in this leather hard stage. The hole is important because the pieces must all eventually be dipped into glaze, and using ones fingers to do the dipping is simply out of the question. A wire hook will be inserted into each piece's hole and used to quickly dunk it in the glaze. Little drill bits are perfect for making these holes, and each hole can be made before or after the piece is turned out of its mold.

Almost finished! Actually, not really. These pieces must dry a bit more before all their imperfections can be trimmed and sanded. Some pieces, especially those with broken tips, are a lost cause and not worth the time it takes to sand them. Others can be sanded into uselessness if the corners become too rounded. As with the previous steps, great care is needed when working with these delicate shapes.

This tall pyramid turned out quite nicely.