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  #1  
Old 12-01-2010, 10:24 PM
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CRT implosion experience?

Have any of you ever experienced a catastrophic implosion of a picture tube in the shop? When I first started working around them in the 60's I was scared-to-death that one might implode if I looked at it cross eyed. Over the years we had several break from various causes, but fortunately never had an instance where the shop was sprayed with glass or anyone was injured.
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Old 12-01-2010, 11:28 PM
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This is scary.
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Old 12-02-2010, 12:30 AM
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That is VERY scary!! WOW! I don't know how I missed that thread. I always considered myself lucky for not having experienced something like that. Now doubly so.
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Old 12-02-2010, 12:59 AM
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Our friend Douglas had a harrowing experience not too long ago...
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Old 12-02-2010, 01:58 AM
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Quote:
Originally Posted by AUdubon5425 View Post
Our friend Douglas had a harrowing experience not too long ago...
Yep, he describes it in the thread David linked above. Mr. Harland has been amazing and inspiring me for awhile now, so reading that even he had such a disaster definitely makes me all the more fearful/respectful of my CRT.

I had intended to carefully remove mine to apply new aquadag and clean the safety glass. Besides not holding it by the neck, handling it like a stick of leaky dynamite, resting it on several folded blankets, etc., are there any other precautions I should take to keep it from rending me to shreds?
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Old 12-02-2010, 07:29 AM
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Shook the building

When I was service manager at Radio Distributing, an Rca parts distributor. One of the guys dropped a 21 inch round crt in the box and shook the entire building which was about 400 feet long. Luckily it was still in the box. He was trying to move it off of a stack of crt's piled three high.
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Old 12-02-2010, 09:17 AM
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Didnt see it happen, but was there for the aftermath:

Customer had aquired his own CRT for his set. I think it was from Sears. He installed it himself. Instead of buying the correct tube, with a bonded safety glass, he went with a less-expensive tube without the safety. I still dont know how he figured out how to get a tube minus the glass.

We went to his home, and there was glass shards allover his living room, and the front of his TV was literally blown out.

He told us that when reinstalling the tube, he had a rough time getting the strap on the bell tightened enough, but finally got it, as he could tell by the rust marks on the strap screw threads. I couldn't tell him about differences in CRT sizes at this point.

The new CRT was in the set less than 24 hours before the implosion. Luckily, the customer and HIS KIDS were not watching TV when it happened, or things would have been much worse... I know the kids sat real close to the screen. I do know that the set was turned on, and the family was in the next room eating dinner.

The customer replaced his living room furniture, and all the carpeting, since even after careful cleaning, there was still glass in everything.

After all this was over, we installed a new CRT in his set... I want to say it was a GE, with the right safety glass, and I still have him for a customer today.
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Old 12-02-2010, 01:07 PM
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For a hoot, about 25 yrs ago, I bought a forlorn old 23" B/W console, took it up to the local dump & shot it w/my Uzi...A buddy taped it...Still have the tape somewhere. Kinda made a Believer outta me...
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Old 12-02-2010, 03:21 PM
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I have to remove the glass on a tube here in the near future, this time I'll be sure to wear some protective clothing. last time I just broke the lens to pieces with a FLATHEAD SCREWDRIVER. Yikes.
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Old 12-02-2010, 07:13 PM
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Quote:
Originally Posted by Sandy G View Post
For a hoot, about 25 yrs ago, I bought a forlorn old 23" B/W console, took it up to the local dump & shot it w/my Uzi...A buddy taped it...Still have the tape somewhere. Kinda made a Believer outta me...
Sandy, that might have been a real collectors item!! Were you drinking or doing some of that I-420 stuff???

I shot at a 25" color Admiral with a .22 rifle one time. It had survived a house fire, sort of. One shot went through the center of the screen. Then, it whistled really loudly until all the vacuum escaped. I've always been a believer in CRT implosion possibilities.

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  #11  
Old 12-02-2010, 10:10 PM
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Ha! Drinking and 420 make me curious about doing stupid crap as well.

Needless to say, I have intentionally imploded many crt's. But, nothing collectible, and always as safely as possible. From about 2005-2008, I must have trashpicked over 100 tv's in my area. Yes, some met a sad fate.
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Old 12-04-2010, 11:50 PM
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I'm glad that link was posted, I somehow missed it this spring. Scary stuff!

The most impressive crt implosion I've seen: when I was a teenager my favorite way to dipose of junk sets was to set them on fire. I had this GE console from about '80, typical-no signs of life, beyond my limited ability. So, I drug it outside and threw some gasoline in the back. Poof! Now, when the heat is really getting to that crt the phosphors will start to darken, and that's a good time to stand back! With this particular set, just as this happened my highschool sweetheart walked around the corner. There wasn't time to tell her what to expect....WHOOMP! Glass went everywhere, proof that the safety of a modern tension band crt has its limits.
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  #13  
Old 12-05-2010, 03:18 AM
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Back in the 70s, when I was in college, I had to dispose of a 20 or so inch B&W CRT in the TV cabinet. The town trash collectors wanted us to let the vacuum out of CRTs by breaking off the little evac seal at the socket. We put it at the curb. Well, this CRT had a bakelite base and the glass seal was not accessible. So I decided to stand back about 25 feet and toss rocks at the CRT neck to snap it off, and be at a safe distance. I missed the neck, but nailed the big part (like where the high voltage connects to). Kaboom! flying glass all over the street and front yard lawn. Good thing I was 25 feet away. I wonder if the CRT phosphors helped fertilize the grass any. Don't remember any brown grass afterwards.
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Old 12-05-2010, 02:52 PM
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My CTC-24 has a minor cataract, and it's gonna stay that way. I've only removed the safety glass from one set, a CTC-17, and that was because the safety glass was broken and it had a bad cataract which was easily taken care of.
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  #15  
Old 12-05-2010, 06:10 PM
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This is an interesting thread! FWIW I will add my 2 cents worth.

WRT the implosions that occured during the removal of the bonded safety glass in an attempt to remove the cataracts. It is very likely that the implosions were caused not by anything physical. It is most likely that the tubes imploded due to the UNEVEN application of heat and cooling. The glass envelopes from shich tubes are constructed, are under a lot of stress from the vacuum inside them. Imagind 14.7 PSI pushing inward on every single square inch of the tubes envelope. We are talking about many many tons of force.

Glass is a very britle material. apply heat to only one area of the tube and you will cause the glass to expand enough that the huge forces on the tube due to atmospheric presssure, are enough to cause the envelope to crack. IF the tube was not vacuum, the envelope might not even crack, but due to the forces on the outside of the tube from the pressure of atmospheric pressure, you are asking for big trouble if you heat the tube unevenly.

Another point. Several years ago somebody posted about a 21fjp22 he had sitting in his garage for some years. Often the tube was sitting with the fase of the tube submerged in water. When he went to move the tube, the safety glass just fell off.

On my lst trip to Hawkeye I asked Scotty about his method of safety glass removal. He said that they placed the tubes in the warming oven. (presumably after the vacuum relieved and the gun was removed. Then whent he tube was warm, they would pop off the safety glass.

Scotty said in the old days, they had a tank which contained water and detergent, and they would place the safety glasses that had been removed into the tank and let them soak for a week. The soaking softened the bonding agent and made for easy cleaning.

From all of the above one might reasonabley expect that it is not necessary to remove the safety glass using heat, provided you are in no hurry. I suspect that simply soaking the front of the tube in soapy water for a long period of time will cause the safety glass to loosen and the PVA to soften so you can remove it easily.

I have a number of color crt's with bonded safety glass. I am going to experiment to see if the safety glass can be removed by just soaking in soapy water for a long time. I will let the group know the results. This may take a month or more so don't hold your breath.
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