example hard wax resin pitch or low melting point metallic alloys all of which may be poured as liquids and will harden at room temperature so supporting the component or part of the component which they surround or embed after machining the filler is melted out using this technique a mandrel would be entered into the scraper ring which would have a diameter rather less than the operating diameter to provide an allowance for machining with the blades or leaves in their operating position the mandrel and scraper ring would then be placed in a mould and the filler poured in and allowed to set the mandrel would then be withdrawn and the blades would be machined to the correct diameter afterwards the filler would be melted out not all the fillers mentioned above are suitable since many tend to bond to the surfaces of the component and do not part cleanly when melted out to overcome this problem it is proposed to use water for the filler material after fitting the mandrel into the ring the assembly is placed in a mould which is filled with water the whole is then frozen to a temperature of 15 u00b0 c or lower the mandrel is withdrawn to facilitate which a release agent may be used to coat the mandral or the mandrel may be heated internally only sufficiently to melt the immediate ice surface afterwards the assembly is re frozen the tips of the blades or spring leaves are then bored out the temperature of freezing is chosen to permit this operation to be completed before the.