I had a few people ask me about master molds, so I thought some pictures might help. These are two master mold currently being used here at the studio. The larger one on the left is used to make Celtic Pony medallion molds, and the smaller one to the right makes molds of the new horse’s tail. The medallion master is the same one that appeared in the post about the marbles – after the plaster was poured and the whole thing was bound up with rubber bands.
The yellow Celtic Pony beside the molds is a rubber insert. It gets placed inside the cavity of the plaster medallion mold so I can pour a plaster “lid”. If I used a tile press to make the medallions, I wouldn’t need this. But since I cast with liquid slip, I need to cover the back of the mold.
The rubber insert is leaning against two of my smaller mold boards, which also appeared in the previous photos with the marbles. My husband made my boards from maple, all meticulously stained and varnished. (Different colors for each different sized set.) It makes me cringe every time I have to use the C-clamps on them, because they are quite pretty.
This close-up of the smaller master mold shows a neat mold-making trick I learned from Barry at Laf’n Bear. See the lines running across the rubber? Those came from Legos! For really small molds like this one, it’s easier to build a mold box with Legos than it is to clamp the boards together. (Larger molds would take too much time, and I suspect my sons would begin to notice if that many Lego blocks went missing.)