Manufacturing Process
Here’s an overview of our process to design and manufacture architectural Terra Cotta and Faience.
Use these links below to click directly to each section.
Survey & Design
Detailed measurements and profiles are taken from each unit type to be replaced. This information is then used to produce shop drawings which contain all the information required to manufacture the block.
Models & Moulds
Information from the shop drawings is used to make zinc templates with the required profile. Lengths of plaster are then run with the template and these are cut to length to make closers. Return units are also made from cut lengths of the profile. If the block requires any decoration such as egg and dart this is applied to the model using modelling clay.
Once the model is complete a mould is made. Each wall is moulded separately with joggle joints to ensure it is correctly re-assembled when it is used. The mould is made up of as many pieces as required to ensure that it can be stripped away without damaged to the terra cotta piece in production.
Pressing
The clay required to fill the moulds is processed on site to the specific requirements of the project. The moulds are filled by hand pressing clay into them. Walls are generally 35mm thick and supporting webs are put into the blocks as required to help maintain shape during drying and firing.
Hand Finishing
The clay is left in the mould until it is dry enough for the block to maintain its shape without support. For most blocks 12-18 hours is enough. For larger, more complicated units this could be up to 4-5 days. Once the mould has been stripped away the surface of the block is hand finished to remove any imperfections and seam lines and to give a smooth surface.
Drying
Once the blocks have been hand finished they are put on pallets to air dry for a few days. The length of time varies depending on the size of the block. The units will then be carefully moved into the mechanical dryers which will remove the remaining moisture during a 5 day operating cycle.
Glazing
If the blocks are to be Architectural Faience they require glazing prior to being loaded into the kiln. Metal Oxide glazes are sprayed onto the surface of the block in layers.
Firing and Despatch
The blocks are loaded on to kiln cars and wheeled into the kiln. Our products are fired to 1170 degrees C and the firing cycle lasts for 4 days. Once fired the units are checked for faults and dimensional tolerance and then packed on pallets for delivery to site.
