richard

I tried to make a bulb using petroleum jelly to exclude air. I placed the electrodes with filament into a glass tube. I filled the center with jelly and the ends with house hold wall filler. I preheated the filament to displace some of the jelly as gas through the ends of the tube where theres a weak seal between filler and electrodes. This was to avoid huge pressure at the start of the first test run. I then placed the tube in a glass bulb filled with CO2 just in case . The bulb worked and I could read by it just, in total darkness. This dosen't show on a camera so I decided to blast it so I could take a pic. http://www.scienceforums.net/forum/attachment.php?attachmentid=1495&stc=1&d=1173294564 It only lasted about four minutes total. The filament tube ended up like this http://www.scienceforums.net/forum/attachment.php?attachmentid=1496&stc=1&d=1173294564