#16
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I'm not aware of any plastic safety glasses. But then, there might be some out there.
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"If you wish to make an apple pie from scratch, you must first invent the universe." -Carl Sagan |
#17
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Every bonded-to-CRT-face safety glass I've seen was glass....I've seen plastic safety glass too but as a separate piece from the CRT usually mounted to the cabinet separately.
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Tom C. Zenith: The quality stays in EVEN after the name falls off! What I want. --> http://www.videokarma.org/showpost.p...62&postcount=4 |
#18
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It can take MONTHS of water soaking, really depends on how bad it is to start with (talking RCA type bonding).
I have one that has been out out side for well over a year, maybe 2, its in a foam packing case (the kind it was sold in as a rebuild). I have a funnel that catches water and drains into the face area. the pins and anode are covered in grease to prevent corrosion. I dug out some of the bad plastic to help trap the water. I was tempted to just bury the face in the dirt (with a soft towel to protect the face) and let the microbes have a shot at it. |
#19
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I don't think water will do much. Solvent would be a better bet. Diesel and kerosene are pretty safe, stable, and won't really evaporate. Dunno how good it would work, either, though. I'd imagine acetone would be the absolute best. It'll eat through damn near anything... but it's as flammable as gasoline, and it'll evaporate after a short time. It'd need to be in a sealed container, with a vent, and stored outside away from buildings and flammable things.
Have you read my name? Or, you know, you could do THIS. Last edited by MadMan; 01-26-2017 at 01:45 AM. |
#20
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My Heathkit GR-370 came with a RCA Hi-Lite 25BCP22, unfortunately pretty much shot. I didn't know what to make of it, I couldn't see where separate safety glass was attached and the tension band was held on with bolts. The tag said it had integral implosion protection. Such a CRT seems very odd to me.
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Audiokarma |
#21
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water works just takes time, need to be patient. heat gun works but not recommended esp on a rectangle tube. ALWAYS where safety goggles regardless of method.
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#22
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///
Last edited by andy; 11-18-2021 at 05:09 PM. |
#23
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Glad for you Andy, hope you never have one go off on you.
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#24
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Just checked the progress. Absolutely no difference. But that was only after 60 hours of soaking. We still have 2 months, maybe three, minimum.
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"If you wish to make an apple pie from scratch, you must first invent the universe." -Carl Sagan |
#25
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what generally happens is the bond to the glass just weakens a bit. The adhesive will not dissolve at all. Again they are all different, worse is better as far as getting them unstuck. What you don't want to do is rush it, esp the critical moment of trying to wedge off the glass. I used wood clothes pins, dig out some of the plastic that is real bad and GENTLY tap them in all around the perimeter. What you are looking for is a very slight upward pressure that is even. If you try to hard the glass will break, then you have a much harder time getting the pins located with even pressure. Once the glass is broken its 10x harder. so again you must go very slow, on a hot day and it can take hours for the slight pressure to work its magic.
Safety gear is a must, I had one go off on me, blew BIG chuncks of glass, very sharp very pointy with an explosion that sounded like an M80 at about 8" away, and it was instant. I got lucky, had my googles on, still got some pretty decent size cut on my arms. heavy chunks went 30ft away. |
Audiokarma |
#26
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Dang. Thanks for the warning. I've been handling these tubes pretty gently. I know they're dangerous, but hearing somebody's account of it really brings it home. I have poor eyesight, so whenever I'm doing literally anything, I have to have my glasses on. Not that eyeglasses are going to help on the event of an implosion anyway.
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"If you wish to make an apple pie from scratch, you must first invent the universe." -Carl Sagan |
#27
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I removed the cracked safety glass from a NOS Channel Master rebuilt tube a couple years ago by soaking it.
It had no cataract at all except a bit of deterioration around the cracked area where air was able to get in. It took a couple months face down in the tub with water above the level of the screen, since the glass was already cracked I just kept breaking off bits and pieces each week as the bond came loose. If it had been in one piece I don't know if it could have been removed without breaking it, maybe after a year of soaking but not in two months. |
#28
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I don't know if this was mentioned but, most bonded tubes have clear tape around the edge to keep air and moisture out, you need to remove it or cut it for the soaking method to work.
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#29
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///
Last edited by andy; 11-18-2021 at 05:09 PM. |
#30
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REAL Good timing on this thread. My first Cat job was easy, and certainly not the norm. Full cataracts are a sight for sore eyes LOL
But now I am working on an original RCA Hi-Lite 21FJP22 from a GE roundie, now owned by another VK member. The cataract was advance to the point where only a 15" central circle was still fully attached. PVA or polyvinyl acetate supposedly only softens in water or methyl alcohol. I used wedges like Dave says above, but once you crack the glass its a PITA (BAM! and it happens instantly). I was definitely not patient so Ill pay the price of robbing another CRT of it's faceglass, which HAS detached 100% So far, I have been using the known dry methods, heat-gun, full-time heating pad-which I highly recommend, scraper razor blades cedar shims. and finally waxed dental floss (NOT ribbon floss) to keep the faceglass warm, chip away at softened the PVA.One I busted the glass, I had to wedge it out in pieces, basically inducing cracks with 2-minute intervals of 2-3" from the heat gun. Once I was down to a 4" piece, I stopped using the heat gun because I did not have a good way to shield the adjacent CRT glass. This morning it took only a razor blade wedge and floss to pop off the last card-sized chunk of safety glass. Below is a picture of what I have been working on over the last week. BTW- a 5 gallon bucket is great at protecting a tube like this. But for a 25XP22, I might opt to build a stand out of 2x4's. CRT cateract heating.jpg Fortunately I too must wear glasses at all waking hours BUT safety goggles are the best practice for all of us when handling these tubes, even newer ones from the 70s onward.
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"When resistors increase in value, they're worthless" -Dave G Last edited by DavGoodlin; 01-27-2017 at 09:14 AM. |
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