Casting a venturi

Just testing if I can do this!

This method of venturi manufacture comprises casting lead into a copper pipe mould using cores which create the specially shaped internal voids.

These cores can be made from several materials, steel, aluminium, wood or even plaster. Each has its benefits and drawbacks:

Steel ... will give an excellent finish to the internal faces of the venturi and is durable. It requires the use of a release agent without which there is risk the lead adhering, making it impossible to remove the cores. A lathe will be required to manufacture steel cores.

Aluminium ...

File:Http://www.palmergroup.co.uk/Bio/veturi and cores.jpg

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I found a "G" clamp very useful to hold the assembly whilst pouring the metal and, although they burn a little, a lump of plywood at each end of the venturi prevents the escape of molten metal which may creep past the cores.

--Bio-rich-time-poor 12:25, 13 November 2010 (UTC)