Even more Slip Casting

Happy New Year everyone =]
I'm sorry that I've not posted for about a month but here we go, quite a big post today to make up for it...
I just managed to finish my second mould at the end of last term. After a session on glazes and how to make/apply them on our first ceramics session of this year, I went into the slip casting workshop and started to produce some casts from both of my moulds. 

This is my second mould. As you can see this is a three part mould that has a spare. The spare is the bottom of the object however the entire thing is cast upside down. This was the hardest mould to make and I feel the fact that it has a part that will be inside what I'm casting means it could be a little tricky to get the mould off. 

This picture is of my first mould filled with slip. The slip we use is a semi-porcelain earthenware slip which has an agent called 'deflocculant' in it. This helps to keep the clay particles in the slip mixture suspended so they don't separate and settle (basically keeping the mixture runny). 

This is a drop out mould and therefore has no spare/plug. All I need to do is simply fill up the mould with slip, leave it for 25 minutes and pour the excess away. The idea is that the plaster (being very porous) draws the water out of the slip, drying the clay in contact with the plaster mould wall. 

This is how it looks when the top part of the drop out mould is removed and the excess clay cut off. To give a good edge at the top you cut the excess off carefully in one direction then sponge back carefully in the other direction. To then get this still slightly plastic piece of clay out of the mould I turn the mould upside down on a wooden board and let gravity pull it out. This means that I do not touch the clay itself, therefore not distorting the shape...

These above are two fired pieces from the first model. To get to this stage I let the clay out of the moulds dry until it is bone dry and then use a process called fettling (basically scraping and sponging) to remove any imperfections. It's easier to smooth the piece off at the bone dry stage as you can hold it without distorting the shape and leaving big finger marks all over it. 

I love this process because once the mould is made you can reproduce the finished piece as many times as you want. Now all I need to do is start thinking about how I want to glaze these pieces. I'm thinking of contrasts so that the two interlocking parts play off each other.