Ok, It’s begun, I was going to title it ‘Starting the ball rolling’ but I’m not sure I can subject you to that level of pun-man-ship!
I purchased a couple of balls to cast, a small one and a larger one – I’ll try some tests using the smaller ball first, and if it works I’ll upscale to the bigger ball.
Starting the casting process.
As you can see from the photos below, I attached the smaller ball to a metal rod and secured it in place with one of those clampy things you find in science labs, I made a fence around the ball using some plastic sheet and sealed the base using clay. I used the ‘Tracy Island’ method to make up my plaster and poured into the mould, up to the half way line of the ball.
It had to be left a day or two to fully set. Once hardened I carved some regestration marks into the top surfcae of the plaster with a coin. Barrier cream, in this case Vaseline, was smeared to the surface of the plaster and the ball, to make it easy to seperate from the next batch of plaster about to be poured in. I replaced the metal support bar attached to the ball for a thicker tapered wooden one, this is to provide a pour hole for the slip when it comes to casting the balls. A new batch of plaster was made up and poured on top to cover the ball and left to set.
When it was all set and tickety-boo, the mould was removed from the plastic wall and split open.
It worked pretty well, I think, the slip cast balls will probably need a bit of tyding up, but nothing serious – any anyway, it’s just a test run – I’ll take more time/care when casting up the full size ball.
The plaster mould is still pretty wet, so will need to dry out fully before I can pour slip into it. So I’ll leave it until after the Easter break and see if it’s ready to be used when I get back…….