Casting Slip

An ordinary mixture of clay and water cannot be used as casting slip as the clay particles tendency to draw together into groups, electric attraction, leaving the water at the top and heavy sludge at the bottom. In order to disperse the clay particles, so that each particles is floating by itself, sodium silicate is used as a media to electrolyte or deflocculant the clay particles. The electrolyte has an effect to causing the clay particles to repel one another and floating individually in the water rather than clinging together in groups. After casting slip is poured into a dry plaster mould, capillary action of the plaster will absorb high proportion of water from the slip, a layer of clay wall will be formed in the inner surface of the mould. The thickness of the clay wall is determined by the length of time of the slip remain in the mould, then pour out the excess slip leave it to set then the casting object can be removed from the mould.

Mould Making

It is the beginning of everything. The object to be cast should have a smooth surface, as it will be easy to remove from the mould.

100_2768A cottling board as its base. Find the centre line of the model. My model is quite easy to find the centre line because it has a seam line I can follow. Cover half of the model with soft clay along the centre line.


DON’T  FORGET  THE  “SPARE”, it is an extension of the mould for pouring slip into the mould. Then place cottling boards around the model, tie it tightly with string.  It is very important that to seal all the edges with soft clay in order to prevent the plaster leaking.  Weight right amount of plaster and water, mix well, skim away all the bubbles on its surface then pour it into the mould. It takes about 30 minutes to completely set. After the first half of the mould has set, cottling boards and soft clay can be removed. Make several natches on the joining surface on the mould in order to easier to locate the other half of the mould when doing the casting. Soap wash the joining surface for three times. To do the other half, place cottling boards around the mould and seal all the edges with soft clay again. Then weight right amount of plaster and water as same as the previous procedure.


I took nearly the whole first term to finish this doll and the head is not done yet.  I think I will throw the head on the wheel instead of making a mould because I can’t completely remove its hair.


slip casting can perfectly pick up complex and fine details of the object.



“The Hidden City” – individual with PDP – Year 1

The Hidden City pecha kucha

I took two times to explore the city. The first time I walked around the city centre and visited the Cardiff Castle. My attention was drawn by objects that have been changed by nature or have a trace of humanity. The second visit of the city I focus on the  back streets of the city. I found hidden art with a hidden story in this exploration.

Through the research of the city project I found objects that were abandoned or still being used by people nowadays. While some of the objects which used to an important part of the city have now been forgotten, others are still in use by its residents. All these objects have a trace of humanity. It seems like they could tell a story by themselves. History is the sum of human experience and is all around us. A modern civilized society cannot be developed without the experience of the past as this is how our modern world was made.


These two art work were introduced, one by my Field’s group member Sophie. In the group meeting she showed us a picture of ‘fore edge painting’, which popular around the 14th century. It is a scene of painting painted on the edges of a book. The painting is like a hidden art and it will only exposing when the book pages are fanned out. The second work by Jin, MA student, he exhibited his work in the uni’s gallery. He used paper kitchen towel and spent tremendous time to create this layers then power saw was used to cut it open. Both of these work are appealing. I particularly like the fore edge painting as it has a sense of ‘hidden’ and the book pages in a way like the layers I would like to make.



The idea of my work is a combination of the past and present. Layers to represent our present days, which were built by the past. Those layers will be surrounded by porcelain slabs. The pure white porcelain will represent the present days. The “City” project, makes me reminiscent the city I come from, Hong Kong, a concrete jungle. The shape of the piece is based on the skyscrapers in the city.

city individual


I would like to try using glaze to create layers’ effect and to experiment an old aging ceramic surface by using glaze, so a series of glaze tests are underway.

tri-aixal blending



Cross blending




Regina Heinz was introduced by Claire Cureen in her tutorial which might give ideas of how to create an ageing ceramics surfaces. Regina Heinz uses slab building technique and grogged Stoneware clays. All pieces are high biscuit at 1080°C and then glazed in several thin layers with biscuit slips, oxides, stains and a Lithium glaze.



Layers experiment

In this experiment I used clay slip mixed with different tone of black stain. After the slip leather-hard dry, I wedged it and slab built a model. It allows me to see whether it is going to work or needed to be modified.






This experiment I used cleaning cloth dipped in clay slip to create layers. I like that tear and wear surface effect but after the piece was fired the layers turned very fragile.



In this experiment, I brushed clay slip onto newspaper then stacked together. It looks more solid. As the piece is required for a certain height, so look after its straightness is essential.





In the drying process of my piece wasn’t dry evenly so it’s warped. As the edges tend to dry quicker, I should have wrapped the edges with plastic strips to slow down its drying process. Due to the time limitation I did not make another one and moved on to bisque firing.


Unfortunetly, my piece has not been fired for some reason. I need to find out.

Confirmed with Matt that the reason of my piece has not been fired was the density and the amount of paper are not suitable for normal firing. It needs to combustible firing for health and safety reason.








My original intention for taking the ceramics degree course was purely to gain technical knowledge of making ceramics. I had never imagined that it would involve such a vast spectrum, but I really enjoy the whole learning experience and it is very instructive.

In the Field project, I have been given an opportunity to re-develop my cognition, thus to understand and re-value myself. Returning to study as my age is very challenging but can be a very rewarding experience as well. I believe that the knowledge gaps resulting from leaving school many years ago is my weaknesses. I have acknowledged that the importance of doing research and I start enjoying of doing research as well. Through the research I constantly spending time on reading a variety of materials, my knowledge has increased and the vision of an individual has also been widened which is conducive to creativity and building confidence. Moreover, my current skill in throwing and hand-building are also average and need to be improved. Both good skills and good ideas are indispensable.

I believe that perseverance is my strengthen. I would like to use my strengthen to improve my weaknesses. To enrich my knowledge base is my major plan in the future. I have planned to spend more time on reading from different sources. I also plan to improve my time management skill. My time management issue in the Field project, individual and the group, led to so much stress, cramming of unfinished work and poor execution.


spiral wedging – through the wedging air pockets inside the clay are forced to come out. You probably will hear air pockets bursting sound in this process.



lots of grog was wedged in terra-cotta before throwing


After the piece are leather hard dry, use a damp sponge gently wipes its surface then the grog will reveal.



Crackle surface experiment by using sodium silicate (the 1st photo). Then tried to use clay slip. I wanted to create a deeper crackle surface but I think I put too much slip on it and it was too dry, so my pot end up with a real CRACK.

P1010604   P1010797 P1010802P1010805


These are my first term throwing experience.  I found out that look for supporting points while throwing is essential, from centering, opening the clay, lifting the clay, shaping the form to turning. Every stage has its own supporting point(s) and everyone is difference.