I decided to make some plaster molds and see how they worked. There are plenty of instructions out there but it’s not particularly hard. This is what I did (simplified) but there are many other ways.
1. Find an object you‘d like to have duplicates of, making sure there are not any under cuts in what you want. For example you’ll see in the photo I used some buttons.
2. Lightly coat the object with liquid beeswax or oil soap– embed the object in clay (it will be a temporary base) so there are not any under cuts.
3. Make a dam (my slit plastic containers) so you have something to pour the plaster into – around the object and pushed into the clay base.
4. Mix your plaster and use a paint brush/ or finger to cover your object and then pour the rest into your container.
5. Let it set up. It doesn’t take long. Remove the plastic container and the clay base (you can reuse that for other bases but not in the mold (plaster is a bad thing to have mixed into a clay piece you are about to dry and fire).
6. Remove the object from the plaster when it dries. Mostly it just pops out pretty good – but it’s a learning process. Let your new mold dry for at least 24 hours before you use it. It needs to dry thoroughly.
In the photos I’ve included you can see the buttons, molds, and some finished clay pieces ready to fire. I know this isn't a step by step instruction but I don't think you need one on such a simple process as a one sided mold.
To make a clay piece in the mold you press your clay into the cavity and let it dry a bit before you pull it out. Like the greenware of the past you will have to clean your edges. Where you see beads in the photo I have attached two pressed clay sides together and then made a hole in the bead.
Onward and Upward….
Tuesday, February 7, 2012
Plaster Molds for Production
I have talked about molds for clay and if you’re my generation you remember the big craze of “ceramic stores”. They are kind of like the paint your own ceramic stores that are around now. But then, you would pick out the poured “greenware”, clean it up, and take it back to be fired – pick it up and bring it home to paint it up using either glaze or paint. They have streamlined things a whole lot with those stores. I remember pouring some of those molds and I have, can you believe it (LOL), a Lark book called The Clay Lover’s Guide to Making Molds by Peirce Clayton.