I’ve seriously neglected my blog with my last post being way before Christmas! Time seems to be flying past and I still feel like I’m in holiday mode.
I thought I’d set myself a little project to start off the year. My birds sold well over The festive period and I found it a bit difficult keeping up with demand at times, so I decided to try making a plaster mold to allow me to produce them a bit quicker.
I started by making a master copy of the bird that I wanted to cast, I added a cone shaped “stalk” to the base of the bird. This is known as the “spare” and is the opening where the casting slip is poured into the finished mold. My master was then left to dry to leather hard.
As I needed to make a two part mold I then marked a line around the middle of the bird where the two halves of the mold would meet. The next step was to submerge the bird in soft clay up to this mark.
I smoothed the area around the bird to make it as neat as possible, then I added a “wall” of plastic to contain the plaster, sealing around the base with a coil of soft clay. The surface of the clay, mold and the inside of the plastic were then all coated with soft soap which acts as a release agent.
Next, things started to get messy! I measured out two pints of water and weighed out 3lb 12oz of plaster. Slowly the plaster was sifted over the surface of the water and when all had been added, it was left for a few minutes to soak. I then started to mix the plaster gently by keeping my hand under the surface to try to create as few air bubbles as possible. After a few minutes the plaster started to thicken and when a finger was drawn over the surface it left a slight impression. It was time to pour. In a smooth, steady action, I poured all of the plaster into the mold.
The plaster was then left to set for about 45 minutes. During this time it heats up and when it had cooled down I removed the plastic wall and gently loosened the plaster from the clay base, leaving the master now embedded in the plaster.
While the plaster was still fairly soft I cut natches into the surface, this was done simply with the aid of a penny.
The natches ensure the two halves of the mold will line up perfectly. Next the plastic wall was reinstated, the base was once again sealed with clay and soft soap was painted on all the surfaces. The plaster mixing process was repeated and the second half of the mold was then poured.
Once again I had to wait for the plaster to set and cool down before tentatively removing the plastic and tapping around the joint between the two halves.
The finished mold will need to be left for several days to dry out and only then can I put it to the test………….watch this space!