Something new for Ashes & Oak in the ceramics department. In the pursuit of developing a range of functional ware I wanted to incorporate my love of hares, but this made the finished pieces expensive due to the amount of time that making each individual hare was taking. Rather than admitting defeat and losing the individual nature of my kitchenware I decided to attempt to make a two part mould. I have never embarked on making moulds before as I've seen so many failures (have a look on you tube and you'll find lots!) and I wasn't overly confident in my own skills.
Once the decision was made it was all about research, and whilst large potteries are making moulds on a large scale I just needed instructions on how to make a simple two part one. Interestingly the internet didn't answer my prayers on this, and it was in an old 1980's pottery skills publication I found what I was looking for. Simple instructions and easy to find tools. My starting point was two ice cream tubs, flexible plastic, a shiny board, powdered potters plaster and soft soap.
After making the basic shape of a hare (without ears or a tail) and a simple bird they needed to be coated in three layers of soft soap. Now whilst the soap looked like normal liquid soap in the pot, it needed to be mixed 50:50 with boiling water, and once mixed it takes on a very different consistency and was described (quite aptly) by my son as 'snot'.
Once covered with the 'snot' the shapes to cast were embedded in wet clay in the bottom of the ice cream tubs. Two extra 'keys' were made in the clay.
Potters plaster was then poured into the ice cream tubs and left to go hard.
After the plaster was dry, the clay and ice cream tubs were removed to leave part one of the mould complete.
Just a little cleaning up and the three coats of 'snot' to the hard plaster, and mask up ready for pouring the next batch of plaster.
In order to pour the next batch of plaster, I needed to make a plastic collar to contain it, sealed with wet clay to a shiny board. I added another small ring of clay inside the collar to create a lip on the second mould.
Pouring the plaster this time was a little more nerve wracking as I could have ended up with plaster all over my workshop, but I was lucky - yes, lucky. I don't believe it was down to skill - the collars worked and it was just a case of leaving them to dry.
The hardest part came once they were dry. Removing the collar and semi-dry clay was the easy bit, getting the two pieces of plaster to part without cracking was more tricky, they were locked together by the solid clay shape in the middle. My small clay ring inside the collar was the answer as it provided a leverage point and eventually the pieces of the moulds came apart. Once the original clay shape was completely removed and the soap washed away it was just a matter of letting them dry completely somewhere warm.
I am quite happy with the two part moulds given that it was my first attempt and we were following old and fragmented instructions. I will definitely make more. The biggest thing I learned was that, as in all areas of pottery, there is no one definitive answer to any technique. When I create the next batch I intend to pay more attention to knocking air bubbles out of the plaster mix before pouring and whilst settling in the mould.
The The best part of this whole process is using the moulds to make my animals. It's a bit like making chocolate eggs - pressing the clay into each half and allowing them to dry a little, then teasing them out and joining them together with slip.
The nice thing about the hare mould is that I can add his ears and tails in many different ways, giving them many different characters and all individual.
I found the whole process great fun and would recommend everyone had a go.
Disclaimer: This post is not intended as a set of instructions, so anyone attempting to follow them does so at their own risk.