30 years ? That's not realy old - I had think of maybe 50 years, since I know special cases of degradiation of old tubes from around the war, especialy when stored in very dry (less than 60%) and warm (average 25 C) conditions. But all of this doesen't affect the glass. 'Only' the coating around the tube (to keep light out). and inside of the tube (sometimes additional coating and of course the phosphor layer at the projection screen). The coating on the outside is often just turned to dust on tubes of this or greater age, since they didn't use any kind of ceramic material - often just special kinds of paper, that turns out to be very teperature and heat sensitive. When these coatings have been kind of hard, they also suffered The coatings on the inside had only the teperature and mechanical problems, and seam to be very stable when stored properly and not to warm (I know TV sets still working after 50 years!). But when exposed to heat, the inner coatings also degenerate. I have seen complete clear Braun tubes ... just some dust in one corner... Gruss Hans -- Ich denke, also bin ich, also gut HRK