How do you make a clay mold and a Cast?
2007-02-19 09:34:13 · 4 answers · asked by Anonymous in Arts & Humanities ➔ Visual Arts ➔ Sculpture
Normally, the mold is made of plaster and the clay is used as slip where the clay (with added ingredients) in thick liquid form is poured in and the plaster sucks the water out of a layer near the plaster. The extra liquid clay is poured out, the layer allowed to dry some and the mold removed.
An open faced mold can also be made in plaster where the clay at a putty consistancy is pushed into to it and after it has dried some and shrunk a bit.
Making molds from random objects requires planning because it must be possible to pull the stiffened clay from the mold without damaging it. This normally involves marking the ridge lines of the model, setting up barriers and putting plaster between the barriers to make a copy of that portion.
There a lot of references on the internet. There are several good books on mold making from ceramics supply places.
Making mo
2007-02-19 15:26:20 · answer #1 · answered by Mike1942f 7 · 1⤊ 0⤋
How complex is the item you want to cast. You can make a simple press mold, a two -piece mold or more.
Basically, for a press mold, seal the object (with no undercuts) to a board with Vaseline. Use clay to make a wall around the object, higher than the object. Then mix the plaster and pour in the mold. Agitate it to remove air bubbles.
In about 20 minutes, it should set up and you can remove the clay and the object. In 24 hours it should be completely cured (check the instructions on the plaster you purchase).
Then, you are set to make many copies of your mold, simply by pressing soft clay into the form, letting it dry and shrink slightly, then it will pop right out and you can make another.
Don't forget - never put plaster into your kiln. It will explode.
2007-02-21 12:28:58 · answer #2 · answered by Lisa 3 · 0⤊ 0⤋
It depends how big the mold is but the last time I needed a cast I made it out of plaster. First you have to have a piece that you can base the cast off of then you put the piece in a container, or box big enough to hold it and the plaster. then you mix the plaster and pour it and let it dry. you should have a mold in no time depending upon how large your piece is.
Good luck
2007-02-21 00:29:28 · answer #3 · answered by snow girl 1 · 0⤊ 0⤋
I say. No.
2016-05-24 17:38:27 · answer #4 · answered by Anonymous · 0⤊ 0⤋