Hi Jeff, I dont think there is a simple solution to protect the pins from corrosion. Even the air humidity can develop leaks in the seals with time. I know that JJ vacuum tube manufacturer uses gold coating on pins of some of their tubes to prevent corrosion (I dont know if it has actually any effect), but this is difficult to do on existing nixie tubes. About the leaks itself - I heard that Tesla once produced large batch of stems with small leaks. They decided not to trash them, but apply a film of varnish (really) around the pins on finished tubes to stop leaking. But this is rather ridiculous story than a recomendation ;-)
Cheers, Dalibor 2016-07-13 4:59 GMT+02:00 Jeff Walton <jwalton...@gmail.com>: > > > > > Dalibor, > > > > As an expert on the materials used in the manufacture of nixie tubes, would > you recommend any method of cleaning or neutralizing the corrosion of the > pins and seals? Is there any chemical that could neutralize the chemical > reaction of the pins which would slow down the process? > > > > Sometimes parts are shipped in bags with materials that protect the finish. > In my early days with Texas instruments, IC’s were all shipped with a silver > plating on pins which would tarnish badly if the shipping bags were unsealed > and they often shipped them in containers with a chemical that was more > chemically active in air to remove sulfides and etc to prevent tarnishing. > They also used coated shipping rails that were static resistant with > corrosion inhibitors. Might there be something that could be placed inside > a clock housing which would sacrifice itself to prevent oxidation/corrosion > of the tube pins? > > > > > > From: neonixie-l@googlegroups.com [mailto:neonixie-l@googlegroups.com] On > Behalf Of Dalibor > Sent: Tuesday, July 12, 2016 3:32 AM > To: neonixie-l > Subject: [neonixie-l] Re: IN-18 Typical Failure Mechanism > > > > > > I guess it is a leak along one of the pins, dumet seals can corrode (it is a > copper plated nickel-iron wire). I would be interested to do a leak test on > a helium leak detector. Of course if you can miss the tube. > > > > Just a very small (tiny tiny!) amount of air is enough to ruin the balance > of the gas inside a nixie tube. Less than one would actually think. > > > > Dalibor > > > > > > Dne pátek 8. července 2016 20:48:04 UTC+2 Jeff Walton napsal(a): > > > > I recently had a IN-18 failure in a clock after about 2.5 year operation. > Over a (4) day period, the digits in one of the tubes stopped working in PWM > dimmed mode. At full brightness, the digits in the affected tube slowly > lost percentages of digit coverage to where only portions of each digit > would illuminate. At the end of the observed period, the digits in the > failing tube went completely dark and even higher voltage on the bench would > not illuminate any of the cathodes. The tube date code was 8505. > > > > I am guessing that absent of any other signs of damage, a seal around one of > the pins has failed and allowed the tube to leak. It was surprising how > quickly it failed and none of the other tubes in the same clock have > exhibited any signs of trouble and look as good as the first day of > operation. Has anyone experienced similar failures with the IN-18? Is this > a typical failure mechanism? Have there been any particular date codes that > others have found to be problematic? > > > > The tube has been since been replaced and the clock is happy again but > curiosity leads me to ask about this experience to the rest of the members > of the group. FYI - these tubes have not been rotated since the clock was > initially put into operation (no handling). There was never any evidence of > cathode poisoning during the operation of the clock. > > -- > You received this message because you are subscribed to the Google Groups > "neonixie-l" group. > To unsubscribe from this group and stop receiving emails from it, send an > email to neonixie-l+unsubscr...@googlegroups.com. > To post to this group, send email to neonixie-l@googlegroups.com. > To view this discussion on the web, visit > https://groups.google.com/d/msgid/neonixie-l/0ec52c6e-eefb-43f8-8e61-349fa55a8e54%40googlegroups.com. > For more options, visit https://groups.google.com/d/optout. > > -- > You received this message because you are subscribed to a topic in the > Google Groups "neonixie-l" group. > To unsubscribe from this topic, visit > https://groups.google.com/d/topic/neonixie-l/A3_V-VYndT4/unsubscribe. > To unsubscribe from this group and all its topics, send an email to > neonixie-l+unsubscr...@googlegroups.com. > To post to this group, send email to neonixie-l@googlegroups.com. > To view this discussion on the web, visit > https://groups.google.com/d/msgid/neonixie-l/5785aebb.515d240a.29439.191b%40mx.google.com. > > For more options, visit https://groups.google.com/d/optout. -- Dalibor Farny ---------------------------------------- phone: +420 724 321 571 http://www.daliborfarny.com FB: https://www.facebook.com/daliborfarnycom Glow Tube Research, s.r.o. Topolna 539, 687 11 Czech Republic VAT ID: CZ29204551 -- You received this message because you are subscribed to the Google Groups "neonixie-l" group. To unsubscribe from this group and stop receiving emails from it, send an email to neonixie-l+unsubscr...@googlegroups.com. To post to this group, send an email to neonixie-l@googlegroups.com. To view this discussion on the web, visit https://groups.google.com/d/msgid/neonixie-l/CA%2BnkT5rGHtU%3DzGd3mL3r%3DNP6KzaDen5i%2Bwgbw%2BCrAzQZufe2PA%40mail.gmail.com. For more options, visit https://groups.google.com/d/optout.
