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Registered Member #99
Joined: Thu Feb 09 2006, 06:10PM
Location: florida, usa
Posts: 637
Hello all, i was attempting to put a ceramic cap ontop ofmy 811a vacuum tube and the metal cap simply broke off.( i have contacted the seller) Anyways, i thought i might be able to solder it back and while attempting, some sort of NASTY gas or vapor shot up from the now severed metal cap and hit my eye. It was rather painful and immediately my eye watered. What is in these tubes?Keep in mind, this is the cap, not the vacuum tube.Should i be worried?Doctor?
Registered Member #65
Joined: Thu Feb 09 2006, 06:43AM
Location:
Posts: 1155
IIRC the 811A is an old triode...
I would talk to a doctor ASAP just in case. Even if it does not contain BeO, Phosphors, or Hg it’s a good idea as even simple eye infections can be really bad. I knew a one eyed chemist a few years back, and just about joined him with the micro-shrapnel incident.
Your eyes are pretty good at expelling contaminates if you don’t wear contact lenses etc. But is it really worth the risk?
Registered Member #56
Joined: Thu Feb 09 2006, 05:02AM
Location: Southern Califorina, USA
Posts: 2445
Did the tube's glass envelope break? I doubt that you get anything from within the tube (being a vacuum tube), I think it is that you burned the glue holding the top cap on. On my tubes it has been a powdery, hard, brown foam. I doubt it was the heat that did it, as I have run 811a's hot enough to melt solder on the glass without damaging the top... If your eye seems ok now I wouldn't really sweat it, but it couldn't hurt to see an optimitrist...
Registered Member #99
Joined: Thu Feb 09 2006, 06:10PM
Location: florida, usa
Posts: 637
The tube is fine, despite its cap missing...My eye doesnt hurt anymore, just a mild irritation now... The seller is going to send another tube, doesnt even want this one back as proof.Good seller huh?
In order to not have this happen again, could i put some epoxy around the caps seal?
Registered Member #87
Joined: Thu Feb 09 2006, 01:36PM
Location: San Jose
Posts: 191
Depends on how hot you plan on running the tube. You might want to peal the epoxy off after the cap is on, so it dosen't melt. Hot solder fume type gasses aren't the best thing in the world, but I'm pretty sure you'l be alright.
Registered Member #56
Joined: Thu Feb 09 2006, 05:02AM
Location: Southern Califorina, USA
Posts: 2445
I got one tube without the cap (it was only like $3 so I couldn't resist) so I pulled the cap off a blown one I had laying around (way to many of those )broke off the cap, used a screwdriver to dig out the brown gunk inside, bent over the piece of wire sticking out the top of the tube, tinned the wire/cap, set it on, soldered the wire, then put a bead of superglue around it
It has been on of my best preforming tubes, and the glue doesn't even start to stink when the is being run way over speck...
Registered Member #229
Joined: Tue Feb 21 2006, 07:33PM
Location: Romania
Posts: 506
The eye has to be washed imediatly with a lot of water. Perform a check at ophtalmology for the integrity of the cornea (risk of xerocorps protrusion, which can give infection later). Oh...and keep your nose away from a VTTC/ SSTC when it is working.
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Vapor from an 811A tube
)broke off the cap, used a screwdriver to dig out the brown gunk inside, bent over the piece of wire sticking out the top of the tube, tinned the wire/cap, set it on, soldered the wire, then put a bead of superglue around it 
