Slumping Glass - Moulds
Learn more about making moulds for slumping glass.
Slumping Glass - Plaster moulds
You need: Latex gloves, a model, clay, wood
Ingredients for mould mix: Ratio by volume - Plaster : 4 Flint :1 Grog:1 and Water: 2.5 -3
Method
a) First make your model. A model is the form that you want to be shaped into the glass. It can be made from clay or can be a found object. Put the model on a wooden board.
Remember the negative/positive dilemma: the model is the positive and the mould the negative – i.e. your glass will finish up the same as the model.
b) Enclose the model with a watertight structure by either building walls of clay or wood with clay plugging the corners and along the bottom. Leave about 4cm around the model.
c) Next mix the plaster mould mix. You will need to make enough to cover the model by roughly 4cm. Measure out the water into a bowl. Add the flint and grog, making sure there are no lumps. Next sieve the plaster into the bowl. Mix the ingredients by hand into a medium thickness. Do this slowly so that there are no air bubbles. Use latex gloves.
d) Carefully pour the mix over your model. Leave for about an hour to allow the plaster to set before removing the clay or object.
e) The plaster mould has to be cleaned of excess clay (if you have used clay for your model), and left to dry for about a week, depending on its size.
Top tips
a) Use an ice-cream tub to pour the mould mix into for smaller projects.
b) Roll a slab of clay over a rough surface – for example rocks – to create exciting textures.
c) Carve into a hardened lump of plaster mould mix with lino cutters to create your own textures/drawings.
d) Pour the mould mix into an ice-cream tub and wait for it to almost set before partially pressing an object into it. Once the mix has set carefully remove the object and the mould is ready to be dried.
Slumping Glass - Clay moulds
Ingredients:Clay, modelling tools
Method:
a) Make a mould by either modelling an object or by pressing an object into the clay.
Think about the negative/positive before you start – this time the clay mould is the negative, so if you want something to stick out in the glass, make a corresponding dip in the clay.
b) When you are happy with your clay mould, leave it to be bisque fired.
c) Once fired paint with 2-3 thin layers of bat (not back!) wash – leaving each to dry before applying the next. This acts as a separator and stops the glass sticking to the clay mould.
Slumping Glass - Fibre paper moulds
Ingredients: Ceramic fibre paper, scissors or craft knife, latex gloves
Method
a) Cut or rip the ceramic fibre paper up and place into a pattern. You can layer up to create different thicknesses. If you prefer you can buy ceramic fibreboard that is rigid and much thicker. Wear latex gloves.
b) Lay the finished pattern onto a piece of rigid fibreboard (kept underneath the kiln)
c) Place glass over the top of the pattern.
d) When fired the glass will simply slump over the fibre paper.
See this page for an overview of slumping glass and mould making
Everything Stained Glass Home Page
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