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File information | |
Filename: | IMG_20170316_220205.jpg |
Album name: | eclipsislamps / Cold cathode and other special lamps |
Filesize: | 2185 KiB |
Date added: | 16 Mar, 2017 |
Dimensions: | 2730 x 2048 pixels |
Displayed: | 38 times |
URL: | http://80.229.24.59:9232/gallery/displayimage.php?pid=5569 |
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NB a small tip for your glass tipoff: this is likely to crack, due to the sharp internal angle where the two sucked-in sides of glass meet. Use a single-jet burner to melt a small bead on the end, with plenty of oxygen in the flame otherwise the iron (III) oxide will come out of the glass and produce a brown coating like on your pinch. Then anneal well at the junction of the bead with the tube. Such kind of tips will last longer with reduced risk of leaking one day.
I have also been attempting hot cathode lamps but failed every time. Hoping you can help me here with your expertise, but i have been chopping the ends off fluorescent tubes and welding them to fresh unused phosphored neon sign glass, connecting to the vacuum pump then getting the air and moisture out the glass by heating it to 270c, then I filled the tube with 10mbar of argon, heated the fillaments on a variable bench supply to yellow hot for 5 seconds (they arced over but not destructively because its current limited) then flushing it a few times with argon then dropping the mercury in and sealing off. I then connected it to a switch start circuit and it starts straight away and runs bright, then suddenly after about 30 seconds of running it goes rapidly contaminated from the cathodes, normally very badly making it fit for only the bin.
Any idea what I'm doing wrong? It works fine when I do this with cold cathodes, even ones I constructed myself and they come out wonderfully and remain clean, its just hot cathodes that seem to do this.
Regarding the discoloration on the glass, im just using a pair of basic butane blowtorches facing each other, I don't have any fancy pure oxygen fueled burners of a forced air one or the money to obtain them unfortunately.
Thanks for the info regarding the glasswork though, information on it online is thin at best so ive had to work out how to do it myself thus far.
In the thumbnail it looked sorta like small Christmas lightbulb