Making a plaster shield to be used as a cornice decoration
Over the last few years I have been embellishing the plaster cornice of a study with shields bearing the arms of institutions and bodies with which members of my family have an association. The number has gradually built up to produce a colourful and decorative display. The process of making one of these shields is shown below.
If a number of shields are to be made it is a lot easier to initially make a blank plaster shield with no charges on it. The necessary charges can then be moulded on the plaster blank using a modelling material such as 'Plasticine'. Fig. 1 shows the charges that represent the arms of the University of Birmingham modelled in 'Plasticine' on the plaster blank.
This is then boxed in as shown in Fig. 2 below so that a mould can be made.
If, as is the case here, the intention is to only make one or two copies the mould can be made using an alginate material, which is a non-reversible hydrocolloid and is relatively inexpensive. The alginate mould is shown in Fig. 3. If a large number of copies were to be made then a much more durable mould such as silicone rubber would be needed - and casting using this material is shown later.
Fig. 4 shows the final casting after painting ready to take it's place on the ceiling cornice -
- and Fig. 5 shows the shield in place together with the arms of Coventry University on the right.
On the next page making a stone plaque depicting a coat of arms to be inset into a pillar.