Bruno,this may be to high tec for the posters and possibly should be a personal E-mail.I am embarrested,being 1/2 FrenchCanadian,I have only been able to accumalate 99cans.Americans think we do twofours every day,wear toques and flannel shirts and say Eh! a lot.This is entirelly true!Sorry I cannot live up to the Canadian tradition.Across the pond,Martin has "checked into the case".Perhaps he can,thats can fill us in the British progress, or should that read empties.Canadians have great knowledge of vacuum de-gassing or sucking back a few beers.
Seriously,It seems strange for all the research to eliminate air entrapment in E/G and add foam which is entrapped air.Hollow E/G beams may and will have resonance which may dupilicate a steel tube.
Larry
L GALILEO THE EPOXY SURFACE PLATE IS FLAT