Build Your Own Arcade Controls Forum
Main => Monitor/Video Forum => Topic started by: Trimoor on July 10, 2006, 11:09:16 pm
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How do I safely pressurize a 15" CRT? The pesky vacuum is standing in the way of my project. I've heard you can break the seal around the high voltage lead with a nail. Any truth to this? I would like to leave the neck intact.
Obviously I will be using eye & ear protection, gloves, and covering it with a heavy dropcloth, but is there anything else I need?
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Wait...what?
Do you want to use this again after you do this?
If not, just face the neck away from you and tap it with a hammer.
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Yes, I have another use for the tube. A small hole near the top is fine, but breaking the neck would ruin my plans. I found a monitor guide on this site saying it's fine to puncture the seal under the HV lead, but I want to make sure.
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Yes, I have another use for the tube.
YES ??.... as in you plan on this tube being functional as a monitor of some sorts again?
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Heh...after you break the seal, the tube is useless for video stuff any more. The vacuum must be maintained.
If you're thinking about using the tube for something else, think again. It's filled with lead, phosphorus and other nasty goodies.
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Yes, I know it will never display images again. Yes, I'm aware of the hazards of the tube. I am a chemist after all. I'll post my little project when it's finished.
So is this a safe way to pressurize it or not?
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In the center of the tube neck, inside the circular ring of pins, there is a small glass tube which is nipped off at the end. It is usually protected by a plastic surround which can be pulled off as it's usually lightly glued. This is where the air is sucked out when the tube is made.
Then get a long tube of some kind just large enough to fit over this glass tube. Fit it over and then push the end of the long tube sideways until the glass tube fractures and all the air hisses in.
Andy
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I would like to leave the neck intact.
A small hole near the top is fine, but breaking the neck would ruin my plans.
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He was talking about breaking off just the little "nipple" that is created when the tube was made. (not breaking the whole neck off)
I have no idea what "seal" you have mentioned is. The "seal" is the nipple where the vacuum was applied.
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From wikipedia covering cathode ray tubes -
http://en.wikipedia.org/wiki/Cathode_ray_tube (http://en.wikipedia.org/wiki/Cathode_ray_tube)
The most simple and safe method to make the tube safe is to identify the small sealed glass nib at the far back of the tube (this may be obscured by the electrical connector) and then (while wearing safety glasses and gloves) filing a small nick across this and then to break it off using a pair of pliers. A loud sucking sound will be heard as the air enters the tube, filling the vacuum. Once the vacuum is filled, the tube is destroyed, but it cannot implode. One must be very cautious not to break the neck of the tube when it is evacuated since there is no plastic coating preventing shattering of the glass.
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According to everything I've ever heard/read...Trying to puncture the tube up near the high voltage lead is REALLY Fracking dangerous.
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It's done. I drilled the metal under the HV lead, and heard the air slowly hissing in. As far as I can tell, the glass is completely intact.
I'll post again when my little project is done.