This is a great use for all those old CRT's that are being replaced by LCD's. I would love to work in an environment with lighting like this.
Technoscrap is a project on reuse of electronic waste in architecture and interior design. From an investigation of visual qualities of mechanical / electronic waste and observation of a natural growth in man made environment grew some concepts of placing disposed PCs and TVs back into our direct environment. As a product, as a decoration and as a statement.
Posted by: Steaming Pile on April 22, 2008 at 8:53 AM
Vacuum.
Make sure you can carefully release the vacuum before reusing the CRT glass. Otherwise, you might have a mess on your hands and possibly an injury as well.
Be very careful with the flyback transformer (that squid-like plug on the back side of the tube is one end of it) - something like 450 volts in those big capacitors. There is a pressure relief nub under the plug at the very tip of the screen stem (need to pull off the plug there and look for it). Crushing the glass nub - it's about 1/8th inch to 1/4 inch inch in diameter - with pliers/diagonal cutters will allow the vacuum to release "slowly" - at a whistling rate. There is about 3-5lbs of lead coating on those CRT's (I think inside) - so when done playing you should look for a good recycling company to handle the material (don't just land-fill it).
Just to add to JS's comment, along with some capacitors on the circuit board, the actual CRT stores mondo voltage. What yer gonna want to do is use a long screwdriver, with a test lead clipped to it, connected to ground (The monitor chassis, for example.) Slide the screwdriver under the rubber anode cap - it's the suction-cup lookin' thing with the fat wire coming out of it. You might hear a good snap. Now it's safe to disconnect the cap and the neck board. Do this several times to make sure the CRT is discharged!
This may look cool, but it is not environmentally responsible and does not belong on on a DIY site. Besides the difficulty of cutting the glass and removing the shadow mask without shattering the whole thing there are toxic phosphors which must be removed from the faceplate.
From Wikipedia: "CRTs may contain toxic phosphors within the glass envelope. The glass envelopes of modern CRTs may be made from heavily leaded glass, which represent an environmental hazard. Indirectly heated vacuum tubes (including CRTs) use barium compounds and other reactive materials in the construction of the cathode and getter assemblies; normally this material will be converted into oxides upon exposure to the air, but care should be taken to avoid contact with the inside of all broken tubes."
Posted by: Marc de Vinck on April 23, 2008 at 5:35 AM
@Culito
Thanks for the info.
@Chris
I knew this was dangerous, but I didn't realize how toxic everything inside a CRT would be. Yes it looks cool, but it is not a DIY link. It is a piece from an art show......I wonder if the maker took all the hazards into consideration?
First of all I stripped the electronics, leaving just the case and the tube. I got rid of the vacuum by use of a hammer in the neck of the tube. No bang, no flying glass etc. Then I cut the tube into shape using a grinder with an inox blade (thickness just 1mm). First making the desired fracture line, than cutting through the glas. I finished the cut using a grinding blade no problem. Furthermore I cut the metal shields inside the tube with a metal cutter and pleeled it through the hole.
Very easy, very simple.
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Technoscrapwas an old art show, held in 2002! As you can see in the info page of the site! ;-)
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@camillo,
I am not claiming it was new, just cool.
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Yeah, no prb. It is cool indeed ! :-)
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I would love to make one, I just have to read up about the dangers of CRT tubes.
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Make sure you can carefully release the vacuum before reusing the CRT glass. Otherwise, you might have a mess on your hands and possibly an injury as well.
Reply to this comment
@steaming
Thanks for the tip, I know the power supplies can be nasty too. Any ideas of the coating on the inside of the glass?
Reply to this comment
Be very careful with the flyback transformer (that squid-like plug on the back side of the tube is one end of it) - something like 450 volts in those big capacitors. There is a pressure relief nub under the plug at the very tip of the screen stem (need to pull off the plug there and look for it). Crushing the glass nub - it's about 1/8th inch to 1/4 inch inch in diameter - with pliers/diagonal cutters will allow the vacuum to release "slowly" - at a whistling rate. There is about 3-5lbs of lead coating on those CRT's (I think inside) - so when done playing you should look for a good recycling company to handle the material (don't just land-fill it).
Safety glasses needed!
Reply to this comment
@J S
Wow, thanks for all the info. I Knew it involved a lot more than just smashing and hacking.
Reply to this comment
Just to add to JS's comment, along with some capacitors on the circuit board, the actual CRT stores mondo voltage. What yer gonna want to do is use a long screwdriver, with a test lead clipped to it, connected to ground (The monitor chassis, for example.) Slide the screwdriver under the rubber anode cap - it's the suction-cup lookin' thing with the fat wire coming out of it. You might hear a good snap. Now it's safe to disconnect the cap and the neck board. Do this several times to make sure the CRT is discharged!
-C
Reply to this comment
This may look cool, but it is not environmentally responsible and does not belong on on a DIY site. Besides the difficulty of cutting the glass and removing the shadow mask without shattering the whole thing there are toxic phosphors which must be removed from the faceplate.
From Wikipedia: "CRTs may contain toxic phosphors within the glass envelope. The glass envelopes of modern CRTs may be made from heavily leaded glass, which represent an environmental hazard. Indirectly heated vacuum tubes (including CRTs) use barium compounds and other reactive materials in the construction of the cathode and getter assemblies; normally this material will be converted into oxides upon exposure to the air, but care should be taken to avoid contact with the inside of all broken tubes."
Reply to this comment
@Culito
Thanks for the info.
@Chris
I knew this was dangerous, but I didn't realize how toxic everything inside a CRT would be. Yes it looks cool, but it is not a DIY link. It is a piece from an art show......I wonder if the maker took all the hazards into consideration?
Reply to this comment
First of all I stripped the electronics, leaving just the case and the tube. I got rid of the vacuum by use of a hammer in the neck of the tube. No bang, no flying glass etc. Then I cut the tube into shape using a grinder with an inox blade (thickness just 1mm). First making the desired fracture line, than cutting through the glas. I finished the cut using a grinding blade no problem. Furthermore I cut the metal shields inside the tube with a metal cutter and pleeled it through the hole.
Very easy, very simple.
Reply to this comment