Project Outline 2: Casting into Cardboard Moulds
This student used information provided by his Grandmother who was evacuated out of London during the war.
His grandmother remembered the early part of the Battle of Britain and her account of a dogfight inspired his design.
Pre-lesson preparation. (Previous week.)
- Explain the project - making references to what they will know, understand and be able to do by the end of the project.
- Give a clear indication of the level of capability the core will be working at, explaining that you will be providing some pupils with extension work at a higher level of capability.
- Look at the LT1 and explain its purpose, making reference to any possible design constraints.
Show examples of designs made using card to create a mould
Tracing of prepared designs on to card
Pupils will prepare a design of maximum size 40mm x 40mm
Trace the design and then run a soft pencil over the reverse side of the trace. Fix the trace to a sheet of card 50mm x 50mm and retrace leaving a pencil trace on the card. Cut out the shape using a rotating head scalpel for safer use.
Preparing the mould
Should the temperature of the metal be too hot (Browning the edges of the card) then turn the thermostat to the lower setting. This will still allow you to pour into your mould without damaging the cardboard mould. Remember that over a period Low temperature setting will reduce the flow so a return to a High setting may be required to re-heat the pewter.
The card mould is placed in between two pieces of 50mm x 50mm x 6 mm pieces of MDF.
Angle Sprue hole of 8-10 mm to make a "pouring funnel" for the metal. No requirement for a vent as when full the air is pushed through the sprue by the overspill of metal. Any small air holes can be filled when the piece has cooled using soft solder.
After the piece has cooled any rough edges can be removed and the surface cleaned and polished. Depending upon the use of the piece, a brooch or a pendant, either a brooch clip can be fixed to the back or an eyelet can be soldered on to enable a chain to be attached.
Casting Tip
An alternative way of protecting the card, as seen in the mould above, is to coat the card area which comes in contact with the hot metal with Hammerite paint.
