25.El this time consisting of a special cluster of land of moulding, resin and flaxseed oil, which melts and eliminated with the casting, as soon as this has solidified. It is placed in castings for gaps in the piece, that they rely on covers or are set in the same mould.If the cores are cylindrical in shape they are manufactured with very simple lathes or used inside a smooth pipe; If its shape is isometric, two pieces of wood which has shaped the particular form have been used and thus make up the base and lid.