Wednesday, 11 March 2009
Breakage in plaster moulds
Having used normal strength dental plaster, and slight undercutting on model details, the results of a first cast are often that the papier mache moulding snaps off any fine mould lobes as it is removed. This is OK if you only need one single moulding, but any subsequnt mouldings will not have the full detail. Two ways to avoid this are to remove the moulding when semi-dry (but this risks layer separation and drying distortion), or to buy much stronger plaster.