Breaking CRT Tubes / General Science and Electronics / Forums

Forums

4hv.org :: Forums :: General Science and Electronics

« Previous topic | Next topic »

Breaking CRT Tubes

1 2 3 next

Move Thread

LAN_403

Omicron

Tue Mar 21 2006, 02:45AM

Registered Member #131 Joined: Fri Feb 10 2006, 09:25PM
Location:
Posts: 185

I was wondering how I should break the CRT for its e-gun. How bad will the implosion be?
This site warns about it. http://scitoys.com/board/messages/9/176.html

[Edit: Fixed URL]

Hazmatt_(The Underdog)

Tue Mar 21 2006, 02:58AM

Registered Member #135 Joined: Sat Feb 11 2006, 12:06AM
Location: Anywhere is fine
Posts: 1735

no implsion at all if you do it right.

Go to the back of the tube and use a pair of wire cutters and cut off the 'tip off' sealing point. It will in-gas after that and then you can cut off the e-gun.

There is a problem here though, the e-gun is very sterile in the tube. Once you break vacuum you expose the nickle surfaces to envornmental gasses and the metal itself will pick up these gasses. Also note that the getter is destroyed now. You will need new Calcium Magnesium and Barium metals when you seal the e-gun into its new home. It will also have to be pumped down while being baked out to remove trace envornmental gasses at this point, then tipped off and getters flashed.

The hardest part I think will be getting a comparable glass to mate with the glass neck of the e-gun because it is not easy finding soft glass these days.

Omicron

Tue Mar 21 2006, 03:05AM

Registered Member #131 Joined: Fri Feb 10 2006, 09:25PM
Location:
Posts: 185

My bell jar is flint glass so that should work. do you think 15 micons is a hard vacuum?

...

Tue Mar 21 2006, 03:29AM

Registered Member #56 Joined: Thu Feb 09 2006, 05:02AM
Location: Southern Califorina, USA
Posts: 2445

I would say that 15microns is a medium hard vacuum.

As to the crt...
There are 3 methods to kill it..
1. put it in a few trash bags and place blankets/towels over it. Then throw/shoot something at it.
2. as said above, break off the fill stem
3, punch a small hole in the copper disk where the hv terminal comes it.

any way you do it, wear safety glasses/cover yourself (long pants/long sleeves, gloves, etc) The chance of glass hitting you with the above methods is pretty silm, but crt glass (leaded/with phosphors on it) is not something you want inside you...

Mike

Tue Mar 21 2006, 03:39AM

Registered Member #58 Joined: Thu Feb 09 2006, 05:40AM
Location: Tri-Cities, Washington, US
Posts: 317

I often just break off the fill stem on the end of the CRT because it gets in my way when scrounging for parts. You will just hear sluuuuurp sound for a few seconds and it will fill with air. I dunno how people are saying there will be phosphores and small glass shards shooting out...

Nik

Tue Mar 21 2006, 04:07AM

Registered Member #53 Joined: Thu Feb 09 2006, 04:31AM
Location: Ontario, Canada
Posts: 638

You get bits bouncing out if you are not carefull and use a hammer or other lress precise methods. As long as you are carefull the worst that will happen is that really cool sucking noise.

Bjørn

Tue Mar 21 2006, 04:27AM

Registered Member #27 Joined: Fri Feb 03 2006, 02:20AM
Location: Hyperborea
Posts: 2058

If you break the CRT as opposed to puncture it you may be met by a shower of glass that move very fast. It is very rare for a CRT to fail violently without reason and they are designed to fail as safe as possible.

Just don't forget that there is 3000 Joule of energy waiting to be released because sometimes they fail unexpectedly in an unpleasant way.

EEYORE

Tue Mar 21 2006, 04:42AM

Registered Member #99 Joined: Thu Feb 09 2006, 06:10PM
Location: florida, usa
Posts: 637

Why not drill a hole in it?I once saw a site where someone was using the crt to create a vacumm in something by drilling a hole in the CRT. May have been Jochen Kronger(spelling).

Matt

Conundrum

Tue Mar 21 2006, 09:23AM

Registered Member #96 Joined: Thu Feb 09 2006, 05:37PM
Location: CI, Earth
Posts: 4062

Yes, this works (and does slightly less damage). The trick is to cover everything with towels then (carefully) drill the centre of the copper anode cap with low speed drill.

If you are careful and quick you can also attach a hose to your CRT while the tube is filling with air and there's a vacuum pump for evacuating air from other projects.

-A

dan

Tue Mar 21 2006, 09:39AM

Registered Member #223 Joined: Mon Feb 20 2006, 06:42PM
Location: Ottawa, Ontario, Canada
Posts: 125

Generally I just use a screw driver and a hammer to puncture that thin metal connection. CRT's are very strong and you don't really have to worry about them spontaneously imploding. I remember trying to smash in the front of a monitor with an 8 oz hammer. The hammer just bounces off. Even with a 4lbs sludge hammer it took a really good wack (I'm no small guy either and it took everything I had) and even then the implosion wasn't even that great. I have probably passed gas that had more power than this.

.

If you are after the electron gun just simply score the base of the neck with a file and give it a good wack. It should come right off. Although getting a clean cut is hit or miss. Also you may want to consider a hack saw with a dull blade coated in wet sand to cut through the neck. It will take a long time though, probably 3-4 hours non stop. But if you are careful you should get a nice even finish which you can then fire polish. Make sure you apply very little pressure while cutting since this can cause the glass to crack and break. The weight of the saw is enough..

Update: I just remembered that I used an angle grinder with a masonry(dimond) cutting disk to cut a thick glass tubes.. It worked very well and was way faster than the hacksaw method. Agian don't use too much pressure.

1 2 3 next

Moderator(s): Chris Russell, Noelle, Alex, Tesladownunder, Dave Marshall, Dave Billington, Bjørn, Steve Conner, Wolfram, Kizmo, Mads Barnkob