Step by Step Mold for Multiple Castings

Since I need so many of my little “Podbabies” for the installation, casting them one at a time just isn’t feasible. So here I’m showing you the process of using castings from the initial single mold to create what I call a multi-mold. There’s probably an actual technical term, but ah…here we go.
So here’s the original podbaby mold, one of the first I made. I made a few castings from this, but the mold was a flawed design. Live and learn.

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I’ve taken some of those castings and prepared the same setup for all the previous molds. 1.Building up a base with oil-clay 2.covering it with a smooth layer of water-based clay 3.including plastic tubing for pour & drain holes. This does take some time.

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Here it is completely set up in the cottles. The little imprints are called “keys,” and they insure that the two pieces of the mold will register precisely with each other. It looks a bit slimy because it’s been coated in mold release. Not 100% necessary for clay on plaster, but I think it helps.

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Here’s the first section of the mold after pouring plaster. Then I just flipped the whole thing over, remove all the clay, clean up the mold and set it back up in the cottles. Pour again and hazahh.

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So here are the two halves completed and cleaned with water and vinegar with new castings in them.

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This is how I actually cast with the mold. From the image above, you can see that there are holes for casting and draining. In the image below, the entire mold has been raised and the draining holes in the bottom have plastic tubes in them and are plugged with oil clay. When it’s ready to drain (about six minutes after I pour the slip), I just set the whole thing over my slip bucket and take the oil clay plugs off the tubes.

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Each piece is then individually handworked and smoothed. I cut out the middle sections, and adjust the dip where they meet. I couldn’t create that dip in the mold itself because it would create an undercut and make it impossible to work with. In reading about it, it was difficult to understand how undercuts affected molds until I actually started doing it. Then it was, “Oh yeah. Okay. That doesn’t work.” Here is a podbaby on one of the stands I’ve been experimenting with. Now it’s just waiting to dry.

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For reference, here’s my first drawing that I did of these little guys a couple of years ago.

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