another cataract removal

[DaveWM]

this was a roundie that has been soaking in a water bath for prob in excess of 6 months. Finally had a need for a good tube so I put it out in the sun yesterday after picking out some of the softened PVA (rca type tube).

using wood clothespins all around the perimeter tapped in until just snug. Took a long time as the sun was not as intense as the summer, and clouds kept rolling in, finally I see a perfect 1/4 wide band start to form in a circle about 1" inboard of all the broken down pva. Did not notice it at 1st, but then it started to slowly move. I kept an eye on it, was barely moving at all. Have to go inside to take care of some business come back, missed all the action it was just sitting loose on the CRT.

Its down right easy and with just low heat (was about 80 outside) I suspect very little possiblility of implosion.

I have another one in the soaking pool.

[marty59]

That's a good feeling when you can be successful at seperating it apart like that! And with minimal stress too. We sure have learned a thing or two along the way perfecting our process.

[Electronic M]

Be very careful not to put the tube in the water if the water is at a different temp. This summer I put a sun heated tube in cold water by acident and the entire face of the tube cracked ruining the tube! Also, it could have been worse if it had imploded......

[DaveWM]

Right. I let the tube come up to heat from the sun, remove the lens, put the CRT in the shade to cool down.

[Kevin Kuehn]

Very cool. I was wondering if a guy could pull off this procedure indoors by using a couple of those electric heating pads across the face of the tube. I’d think heating pads would have the same gradual heating characteristics as the sun. Or maybe not even use heat, just the slow gentle pressure of the wedges over several days. Water sure seems to be key in softening the edges first.

[Electronic M]

drh4683 has a youtube video where he uses halogen work lamps to pre-heat the tube, and then uses a heat gun to finish the thing off which worked well for him. I might of added some more lamps to get it hot enough to abandon the heat gun approach for piece of mind.

I'd be scared of using heating pads due to the uneven heating they produce.

The sun seems to gradually and evenly get the tubes hotter than the air around them from my experience.

[DaveWM]

I would stay away from heat guns or heating lamps, too much heat, just not needed. pressure alone may do it if given enough time. Here in Florida its pretty much year round sun so its not a problem getting heat that way.

the Other good thing about this method is you spend very little time actually near the CRT, with heat guns requiring constant movement, put you in the kill zone a lot of the time.

[bgadow]

The one I had crack last year (thankfully I had aired it first, as the crt was a dud) was due to heat lamps. I didn't exactly figure it out but I think it was just way too much heat and something had to give. I have had very good luck with a heat gun but I'm not sure if my nerves will let me do another one that way.

[Electronic M]

Speaking of nerves one thing I never mentioned in my cateracting thread was how I choked in fear when I set the tube in the water and noticed the temperature difference. I thought to my self "I'm holding a bomb...do I pick it up and pray that it doesn't implode...or do I drop it and run...will droping it an inch set it off...can I get far enough away before it goes boom?". I spent too long making up my mind IMHO. I was scared freaking stiff as I had no protestive gear on at all! Part of me wishes I had pulled it out the second I felt the cold as that might have saved it, but I had seen thin home glass wear break instantly and did not know what to expect from a CRT.

[miniman82]

Just another reason to stick to tubes that don't have lenses, IMO. 21(AX/CY/FB)P22 FTW!

[Electronic M]

I do have two 21FBP22 (okay one is a GUP22 but is basically the same thing). The sets that use the earlier ones are too expensive for me right now barring the unusual find of one in the wild. My first memory of TV was watching my parrents then ancient Motorola WID delta gun rectangular set as an infant so rectangular delta gun sets give me a wierdly strong feeling of nostalgia/dejavu.

Ya know nick, that tube I was talking about was the tube in that Zenith set I bought from you........

[marty59]

May sound simplistic or silly to mention, but before I'd soak any tube in water, fill some buckets and let them set for as long as needed alongside your CRT to let the temperatures stabilize between the two. After I started my process, I would refill my bucket in case I would have to add any later.

[miniman82]

Originally Posted by Electronic M

Ya know nick, that tube I was talking about was the tube in that Zenith set I bought from you........

I have another square set you still need to pick up, when you stopping by?

[Electronic M]

Unless it has a 22JP22 in it or you want to trade consoles I can't take the last one unless I pull the chassis and CRT and then scrap the cabbinet (I really hate scrapping something that can/should be preserved). I'm out of storage space! Though if you still have that 16" monochrome tube that would work in my porthole I may pay a visit.

Happy Thanksgiving!

[miniman82]

Originally Posted by Electronic M

if you still have that 16" monochrome tube that would work in my porthole I may pay a visit.

Nope, I gave that to Mark.