Dead CRT disposal?
 

Environmental concerns aside, what's the safest way to de evacuate a couple old CRT's so that they can be disposed of? I think I remember reading someplace that you can take a center punch to the keyway of the neck connector, which would break the evacuation stem? I'd really prefer it doesn't implode.

I have never had one implode by knocking off the tip seal...I usually use just a small hammer to crack the tip. Driving a sharp scribe through the HV button works well also.
If you wrap in an old heavy blanket, it will provide a measure of protection and also contain most pieces for easy disposal should the tube implode.

jr

I've always just hit the neck with a hammer. Usually I leave the tube in its cabinet if possible, but if I can't, it's still safe at close range. Never had a tube implode yet. If you watch Youtube, there's a video of a guy pouring liquid nitrogen down a pipe that ends just above the face of an upwards facing tube... I was amazed how quickly it imploded!

Cracking the evacuation tip is my usual method for "modern" era tubes (those that have some form of integral implosion protection). Have used the anode button method a ew times, as well.

An older tube without any tension band or bonded faceplate can really be a bomb if it suddenly lets go, and I wouldn't want to be right next to it if it did. I would suggest putting the tube inside a plastic trash bag, then a HEAVY cardboard box. Seal the box, and then pop the envelope with a thin metal rod piercing the side of the box.

A pellet gun or slingshot from a decent (40-50') distance makes a nice science demonstration, if you have a safe place to do it (and the ability to cleanup the glass afterwards). :D

My vote for the scribe through the anode procedure.

A well-aimed 30.06 slug makes a nice science experiment and marksmanship demonstration...

Put it in a plastic trash bag (If you're British, that's a black bin liner), stand back eight feet and throw a rock at it.

I was WAITING for somebody to come up w/the most FUN way of dispatching a dead CRT...MY Uzi on full-auto works DANDILY, too...But everybody thinks I'm a "Froth-At-The-Mouth" Gun-Nut type, so I can't talk about it...(grin)

Just ask the people that bumped the neck when they carried it through the door and weren't watching. Hissss! :sigh:

I just can't help but think of Arnie's line in Terminator 2.... "Uzi 9 millimeter" You have to put on his accent when you say that! :)

As to knocking the neck off a CRT I was carrying, I luckily haven't had that happen, but I did break a CRT glass seal when fitting a yoke. The plastic cover had rotted away exposing the seal. It took ages before the hissing stopped, and when powering it up, there was a lot of internal arcing. Of course, I was 12 at the time!

I've used the anode button on the last 4 or 5 I've done; it doesn't take much of a tap with a hammer to poke a hole right there. I'd still suggest a heavy blanket over it, just in case. Nice thing is you end up with absolutely no broken glass (assuming it works right).

Beretta 92FS. At 50 feet I can take off the neck for you, if you like...:smoke:

Better make it SHARP, and fine-gauge, or the force of driving the punch or scribe into the metal anode, will implode the tube by breaking the side wall.

Charles

How about a sharp drill bit to the anode on a cordless drill? :D

SR

I have read about the drill method before. I suppose the idea is to stop when you hear a slow Hsss. I would still wrap the victim in a quilt and wear protective gear, just in case. One sharp piece of glass to the jugular can really spoil your day.

Phil Nelson

I usually just give the neck a good sideways whack, never had a problem but I suppose there's always that one n a million chance something will go wrong.

I don't like the punch on the anode methode, like Charles said, it better be sharp or you will be putting a lot of stress in the worst possible place, a drill would be safer I think.

A drill through the end of the base cap is pretty good too, it just breaks the evacuation nipple and that is much thinner glass than anyplace else.

That's what i do with the 7JP4's because there's no anode and no real neck to speak of, it's the only safe place to puncture those tubes.

Yeah, i was drilling the anode hole out to stick a cord through it. Yeah, you guessed it... was attempting a lamp, folks did it with booze bottles, so i figured what the heck?

Unfortunately, the glass cutter i used didnt cut the neck right and i scrapped the project..

So... did i open a can of worms, anyone attempt this or SUCEED??? :D

SR

Oh I agree! But you would be surprized at how easy a little light tapping of a scribe will punch through. The anode button is pretty thin. Even preferred as bgadow mentions.

Yes, I never would have thought about it until I was given a NOS RCA crt from the 80s, like a 27". The instructions inside said to evacuate the dud before mailing it by punching a hole in the anode. I usually use a large, sharp-pointed nail though an ice pick would work well. By the second gentle tap I'm usually through.

Let me know if you figure out how to cut the neck cleanly (hot wire maybe?). I have a couple of dud oscilloscope tubes that could make nice lights.

Phil Nelson

Today was the day - I had myself wrapped up like a mummy, although nothing dramatic happened. :D First I sharpened up an upholstery regulator(basically an ice pick) and gently tapped that into the HV anode. The anode metal seemed rather soft, and it appeared that the point of the regulator seemed to be helping keep the pinhole sealed. So I agitated the regulator around gently and could then hear the air softly hissing in. I also had a couple clear plastic bags wrapped around the CRT, so those were possibly dampening the hissing sound. Anyhow, mission accomplished. I really appreciated everyone's input. Not so scary anymore. :thmbsp:

It would be cool to see what happened to the picture if you had the CRT running at the time!

I've had the UNpleasure of seeing that happen... I had just finished doing setup on a new tube in a CTC-81 back in the 80s, and I let the back cover slip down while I was putting the screws in... A gentle hiss, and in a few seconds, the neck flashed blue, and then the HV started arcing all over the place as I yanked the AC cord out of the wall. The customer wasn't in the room, so I got away with saying "Seems to be a problem with the new CRT... Back tomorrow with another one no/charge".

As far as self-protection for while you're trying to de-bond safety glass to remove cataracts, (or busting a tube to discard if it's compromised or if you're concerned or inexperienced), I wear motocross gear including chest protector, kevlar pants, and helmet with neck roll & stone-proof goggles.

Charles

When I was a high school student, I worked in a TV shop. Their method was to simply grab a pair of pliers and break off the evacuation nipple. It is safe as it lets the air in gently without risk of implosion.

I would always keep away from the bell of the tube since risking the integrity of the bell could lead to a nasty mess. Knocking the neck off is quick but more risky. Ilike to keep hammers and other heavy metal objects away from glass CRTs.

How awful! All that work setting up not to mention the cost. You were very lucky that you were alone when it happened. An easy mistake to make, I did similar to a colleague's TV. I hadn't really started to work on it, but the back was off and I knocked the back of the CRT and heard the slow hiss. I felt terrible until I priced what the repair would have cost and realized it was a no goer anyway. Still, it's an experience that's not easily forgotten..

After I aired the 21AMP4 I wanted to salvage it's connector, so I whacked at the neck with a small hammer. Could not believe how hard I had to hit it to bust the neck off.

I've noticed that, some of the necks seem really thin, whereas others are tough hombres! I use a 2 Kg metal mallet when airing CRTs, plenty of force to be had there, especially if I just drop it onto the neck from about 3 or 4 feet.
Once I had a tube break in such a way that the gun shot forward into the shadow mask! It looked really weird seeing the front of the gun protruding through. The phospor had been blown away from the inrush of air.

Here's a picture of one that did just that. You can see the gun assembly stuck forward in the shadow mask. It actually blew glass off the front of the CRT.

http://i452.photobucket.com/albums/q...nderson009.jpg
http://i452.photobucket.com/albums/q...nderson002.jpg

I never heard of any CRT firm, that would want the tube back, not under vacuum.
When you turned in a dud for a replacement, the first thing they did was check for vacuum. They used a hand held high voltage probe. :yes:

I remember my sister's KV-9000 Trinitron died several years ago, I laid it face up in a garbage can & proceeded to throw rocks at it to break it...It was NOT easy...Think I finally had to use a cinder block & it took several attempts at that.

Thats' very interesting! The tube I was talking about was also one of the old delta guns, coincidence?