I wanted to create very light hollow metal ornaments that could float
by the buoyancy of the air inside. I wanted to use metal because some
parts of the object would need to withstand an ambient temperature of
about 100-150 degrees celsius. I figured a good thickness for the
metal would be about 0.5 mm, enough to withstand moderate handling
without deforming. I'm not a craft expert, but I the best idea I
thought of would be to do the following:

1) create a master object from clay or polyclay
2) use the master to create a mould from plaster
3) use the plaster mould to make a wax copy of the object
4) apply an initial film of nickel by solution or aerosol spray
5) plated the metal of choice onto the nickel to the desired thickness
6) immerse the object in boiled water to melt the wax
7) wax can then be skimmed off and recycled

The object shape could be quite complex, for example a flower with
petals or miniture scene with a house or something. I might end up
producing small batches of a 1000 or more. Can anyone comment on my
proposed technique? Would there be a better or simpler way to do it?
How would an industrial production line do something like this? I
realise I can enlist the services of metal plating companies to deal
with some of the work. Comments please.

Many thanks,
Erik