Assigned Reading--McCreight Ch. 1-Models

An ingot mold became an object mold--discovered was that an almost complete form could be poured.

China-->7000 years ago-->Egyptians-->Greeks-->500BC (blast furnace)-->Indust. Revolution

Mold-the negative impression into which a softened material is pressed, poured, or injected to acheive a specific shape

The melting point of the material restricts the choice of mold.

Piece Molds-can be separated and consist usually of only two pieces.

Waste Molds-made in one piece then broken to relieve the piece being cast and only used once.

Lost Wax Process

1. wax model

2. mount wax model on a sprue (wax rod)

3. mount in base fitted with a flask (watertight open-ended cylinder)

4. investment (plaster) is poured into flask; remove air bubbles

5. when investment dries, burn out model in kiln

6. pour molten metal while model is still warm

7. cool; quench in water; break open mold

Only melt wax in a double boiler to avoid it reaching its flash point and catch on fire.

Wax expands as it melts.

Waxes-beeswax, carnuba, candelilla, ceresin, ozenite, synthetic.

Resins-damar, balsam, kauri copal, shellac, rosin (all tree saps)

Fillers-talc, starch, chalk, soapstone, pumice, wood flour

Liquidus point-point at which wax melts

Solidus point-point at which wax hardens

Plastic range-an inbetween state at which the wax is easily worked

Carving wax-hard; made to be worked reductively or subtractively

To bond two pieces of wax together, both points of contact must be molten.

Best to use a spiral saw blade to cut wax-cut outside of the intended design.

It is better to dedicate separate tools for metal and wax.

Best to use a saw blade, then file, then use scraping as a technique (dental tools work well)

The metal (final product) will weight between 10 and 20 times the wax model, so don't hesitate to make the model thin. The mass can be reduced by scraping or hollowing out some sections.

Pieces of wax can be reused as long as they are not contaminated.

Denatured alcohol or Lamp fuel are the only fuels to be used for this kind of wax working.

Soldering irons with a dimmer switch are good replacements for electric wax pens and offer much control.

Make etchings to press hot wax into, through a vice, to produce an imprint.

Files, sandpaper, and steel wool are inappropriate finishing tools for modeling wax.

Dripping wax will produce interesting shapes and effects.

Pressing forms into clay, then filling them with hot wax will also make interesting shapes. Use potter's clay or any clay mixed with water. Modeling clay will melt when hot wax is poured over it.