Vacuum Moulding seems to crossover with some expensive equipment available but also some good low cost techniques. While thinking about a shell for one of the minisumo and ways of construction I found this:-
http://www.youtube.com/watch?v=eUB58z8apTE
The start of the associated article can be found here: http://makezine.com/11/vacuumformer/
It might be a while before I get round to this but it looks promising
regards,
colin
