5 ms·

This video and reading the recent article referencing Brimar valves (of the vacuum tube variety) [1] led me down the rabbit hole of, how hard can it be to make

by nickt 3y ago

This video and reading the recent article referencing Brimar valves (of the vacuum tube variety) [1] led me down the rabbit hole of, how hard can it be to make a few CRTs. Despite growing up with them, it turns out I had no idea. Lots of ovens and nasty chemicals involved - see for yourself in this great old video [2]. I wonder if anyone in the retro scene is eccentric and rich enough to give it a go… [1] https://brimaruk.com/ https://brimaruk.com/ [2] https://youtu.be/32yYfTVIzBE https://youtu.be/32yYfTVIzBE

TedDoesntTalk 3y ago
> https://youtu.be/32yYfTVIzBE https://youtu.be/32yYfTVIzBE Great video. I’ve got to 6:06 so far no mention of nasty chemicals yet.
- skissane 3y ago
  Transcript: https://youtubetranscript.com/?v=32yYfTVIzBE https://youtubetranscript.com/?v=32yYfTVIzBE From the transcript (I dislike watching videos), it appears the video never discusses the chemicals involved - but I’m sure some of them are rather toxic. It is an old film, and when it was produced people didn’t see the toxicity of chemicals used in manufacturing processes as being as worthy as note as people do today - both environmental and workplace health/safety issues were less on people’s radar. Plus it obviously is marketing/PR for the manufacturer, and who wants to mention toxic chemicals in something like that?
  - hetman 3y ago
    It's worth mentioning though that in general as our technology has gotten more exotic, so too the chemicals needed to manufacture it have gotten more toxic.
    - snthd 3y ago
      Is there some underlying rule/"law" of fabricated products shrinking in scale requiring increasing energy density/control for their manufacture (more reactive chemistries) presumably to counter a general backdrop of entropy / entropy-density?
- Aeolun 3y ago
  10:37 has hydrochloric acid
  - mrob 3y ago
    Sounds like hydrofluoric acid to me, which is even more dangerous. But seeing as you're making a vacuum chamber anyway, perhaps oxygen plasma could be substituted. https://en.wikipedia.org/wiki/Plasma_cleaning https://en.wikipedia.org/wiki/Plasma_cleaning
CTDOCodebases 3y ago
I remember hearing the main issue is that the glass is made up of a significant amount of led so even if it was commercially feasible it would be legally impossible to sell, import or manufacture new CRT tubes due to the regulations many developed nations have in place.
- willis936 3y ago
  How are car batteries sold, imported, or manufactured?
  - CTDOCodebases 3y ago
    That was the explanation I was given when asked. I imagine different regulations apply to different products. Also obviously different countries have different regulations. Lead makes up 20-25% of the contents of the glass of a CRT tube so I imagine that restrictions like those listed in the link below would cause issues. https://dtsc.ca.gov/restrictions-on-the-use-of-certain-hazardous-substances-rohs-in-electronic-devices/ https://dtsc.ca.gov/restrictions-on-the-use-of-certain-hazar...
  - elzbardico 3y ago
    There are exemption. And if you think of it, it is a lot easier to properly dispose and recycle the plates in a car battery than in electronics solder or glass.
- jdietrich 3y ago
  I can't speak for any other regulations, but the EU's RoHS has a specific exemption for lead in the glass of cathode ray tubes. CRTs are still being actively manufactured, primarily for avionics and military applications. https://eur-lex.europa.eu/legal-content/EN/TXT/?uri=CELEX%3A02011L0065-20230301 https://eur-lex.europa.eu/legal-content/EN/TXT/?uri=CELEX%3A... https://www.thomaselectronics.com/manufacturers/ https://www.thomaselectronics.com/manufacturers/ https://moores-glass.co.uk/products/cathode-ray-tubes/ https://moores-glass.co.uk/products/cathode-ray-tubes/
  - 3y ago
Aeolun 3y ago
It may just be me, but this video actually seems detailed enough to replicate the process if you have the right materials/machinery.

by nickt 3y ago

TedDoesntTalk 3y ago

> https://youtu.be/32yYfTVIzBE https://youtu.be/32yYfTVIzBE Great video. I’ve got to 6:06 so far no mention of nasty chemicals yet.

skissane 3y ago
Transcript: https://youtubetranscript.com/?v=32yYfTVIzBE https://youtubetranscript.com/?v=32yYfTVIzBE From the transcript (I dislike watching videos), it appears the video never discusses the chemicals involved - but I’m sure some of them are rather toxic. It is an old film, and when it was produced people didn’t see the toxicity of chemicals used in manufacturing processes as being as worthy as note as people do today - both environmental and workplace health/safety issues were less on people’s radar. Plus it obviously is marketing/PR for the manufacturer, and who wants to mention toxic chemicals in something like that?
- hetman 3y ago
  It's worth mentioning though that in general as our technology has gotten more exotic, so too the chemicals needed to manufacture it have gotten more toxic.
  - snthd 3y ago
    Is there some underlying rule/"law" of fabricated products shrinking in scale requiring increasing energy density/control for their manufacture (more reactive chemistries) presumably to counter a general backdrop of entropy / entropy-density?
Aeolun 3y ago
10:37 has hydrochloric acid
- mrob 3y ago
  Sounds like hydrofluoric acid to me, which is even more dangerous. But seeing as you're making a vacuum chamber anyway, perhaps oxygen plasma could be substituted. https://en.wikipedia.org/wiki/Plasma_cleaning https://en.wikipedia.org/wiki/Plasma_cleaning

CTDOCodebases 3y ago

I remember hearing the main issue is that the glass is made up of a significant amount of led so even if it was commercially feasible it would be legally impossible to sell, import or manufacture new CRT tubes due to the regulations many developed nations have in place.

willis936 3y ago
How are car batteries sold, imported, or manufactured?
- CTDOCodebases 3y ago
  That was the explanation I was given when asked. I imagine different regulations apply to different products. Also obviously different countries have different regulations. Lead makes up 20-25% of the contents of the glass of a CRT tube so I imagine that restrictions like those listed in the link below would cause issues. https://dtsc.ca.gov/restrictions-on-the-use-of-certain-hazardous-substances-rohs-in-electronic-devices/ https://dtsc.ca.gov/restrictions-on-the-use-of-certain-hazar...
- elzbardico 3y ago
  There are exemption. And if you think of it, it is a lot easier to properly dispose and recycle the plates in a car battery than in electronics solder or glass.
jdietrich 3y ago
I can't speak for any other regulations, but the EU's RoHS has a specific exemption for lead in the glass of cathode ray tubes. CRTs are still being actively manufactured, primarily for avionics and military applications. https://eur-lex.europa.eu/legal-content/EN/TXT/?uri=CELEX%3A02011L0065-20230301 https://eur-lex.europa.eu/legal-content/EN/TXT/?uri=CELEX%3A... https://www.thomaselectronics.com/manufacturers/ https://www.thomaselectronics.com/manufacturers/ https://moores-glass.co.uk/products/cathode-ray-tubes/ https://moores-glass.co.uk/products/cathode-ray-tubes/
- 3y ago

Aeolun 3y ago

It may just be me, but this video actually seems detailed enough to replicate the process if you have the right materials/machinery.