@Pilou: C'est amusant que ce soit toi qui me réponde aussitôt :)

Note for all: Frenchy Pilou is 'the french MOI evangelist' and I discover MOI after reading his (thousand of) post about in other 3D forum.

Explain 'Extrude it' please...
Edit: I can extrude circle but need many op. to clean the solide (delete old face, extrude, join, ...) or im missing something simplier?