One of the most preferred hand shaping methods for those interested in crafts and ceramics, the plastering technique is an ideal method for creating creative ceramic forms using simple tools. In this article, we will explain step by step how you can apply the plastering method to shape the bowl form.
What is the Plastering Method? The plastering method is a technique in which the shaping process is supported by a mould. It is usually worked with plastic clay, which is shaped by hand by plastering it onto a prepared mould. The method is very popular for amateur work because it can be easily applied at home or in the workshop without requiring a large financial investment. Plastering technique is applied in two ways as internal plastering and external plastering: Internal Plastering: For deep forms (e.g. bowls), the clay is plastered on the inner surface of the mould. External Plastering: For more superficial forms (e.g. plates), the clay is plastered onto the outer surface of the mould.
Mould Preparation Mould selection is very important for the plastering process. The mould you will use must be made of a hard and durable material. In the first place, cubic or cylindrical containers that you can find on the market can be useful for you. Since you will be plastering clay on the inner surface of the mould, you can prepare the mould by using a thin plastic bag, cloth or paper to prevent the clay from sticking to the mould. This step will make your work smoother and allow the form to come out of the mould easily. Preparation of Clay Plastic clay should be used for plastering. Different coloured clays can be used together to create more colourful and attractive products. However, the consistency of the clay is important; a slightly high moisture content makes it easier for the clay to adhere to the mould.
Preparing Marbles from Clay In the plastering method, small pieces of clay are broken off and rolled in the palm of the hand to form balls. The size of these balls depends on the size of the form you are shaping. As the form grows, the size of the balls should also increase. Using balls of equal size in the same form makes the form look aesthetic and balanced. Placing the Balls in the Mould Place the prepared balls starting from the centre of the mould outwards, side by side and without overlapping. For large forms, it is important to work quickly so that the balls do not dry out. If you need to take a break, you can cover the form with a plastic bag to prevent it from drying out. Assembling and Plastering Balls To assemble the balls, ‘slime’ is used, which is obtained by mixing plastic clay with a little water. This slime is used to glue the marbles and stabilise the form. Glue the balls together by lightly patting each point of the form by hand. Be careful not to press too hard; otherwise, lumps may form in the slime and the wall thickness of the form may change.
Resting the form in the mould After plastering and joining the marbles, let the form rest in the mould in a natural environment. At this stage, the form gradually starts to shrink and can be easily removed from the mould. It is important to wait long enough for the form to demould, otherwise deformation or cracking may occur. Demoulding and drying When the form reaches leather hardness, it is carefully removed from the mould. The removed form is left in the natural environment until it dries completely. After drying, wipe the surface with a damp sponge and apply the finishing touches. If necessary, you can clean the burrs with a knife.
Final Thoughts Creating deep forms such as bowls with the plastering method is a very enjoyable and creative process. With enough patience and careful work, you can achieve aesthetic and useful ceramic forms. After your form has dried, it will be ready for bisque baking. After trying this method, you can create unique designs by experimenting with different shapes and colours.