[bgadow]

An update, or, Bryan's further adventures with swimming picture tubes...

So, before the weather turned colder I decided to drag out the kiddie pool one more time and take a stab at a couple more with cataracts. As you'll remember, I last was able to succesfully remove the faceplate from a "green halo" tube by soaking it in a pool for several days, then using gentle prodding to pop the lens. My next "patient" looked to be easier: a "gray halo" tube. This is the more common type which can be removed with a heat gun. How would it respond to the water? I expected it to take less time. I have had past experience with this type in which tubes exposed to the weather for years on end had a completely disintegrated cataract. The CRT in question is a Sylvania; these usually have the green stuff. This one is kinda early (first part of 67) and has a not-so-common non-frosted faceplate. So, into the water it went. I checked daily. Much to my surprise, there was no change in the PVA. Something I noted: the edges of the green PVA tend to be rubbery and sticky, while the gray PVA is fairly hard, sort of like cured Duco cement. The green stuff absorbs water fairly fast, turning white and losing its grip, but not the gray stuff. I let the tube sit for about a week. I could just start to see some deteroration around the edges. Unfortunately it had rained and a little bit of the aquadag had washed loose. With more storms forecast I decided not to chance it, and removed the CRT. I then proceeded to remove the faceplate the "old fashioned" way, with a heat gun. No problems there. While working on it I noticed some deep scratches on the faceplate. I decided finally to replace it with a frosted glass off a dud tube I have. (I had already removed that glass previously) All went reasonably well.

Next tube: 22GWP22 in a Motorola, green halos. Maybe the deepest green halo I've seen, enough that it was distracting to watch. Mean set to work on-CRT has to be removed from the front, which might be easy except the front trim has to come off; the chassis still has to be pulled. This set had a rough life, with a dented top and several broken mounts on the trim. When I was unwrapping the tape from the edge of the CRT I found that the faceplate was cracked on one corner. It's a good thing it didn't go further-that almost certainly would have condemned the set. Then, I did something really stupid. I was prodding under the edges of the glass with a popsicle stick, since the PVA was quite soft. That's when I heard a terrible "C-R-A-C-K!" and that was the end of that faceplate. I could blame it on the previous crack, but that would be sour grapes. It's my own dumb fault.

Luckily I had some spare tubes in the attic. One proved to be a tension band tube. A quick check revealed it might be a little tricky to mount. The original mounting band on top of the tension band would make for a tight fit. The other spare was a Channel Master with gray cataracts. (actually, frosty white) It tested strong on blue & green guns but the red showed no movement; could just be due to pin corrosion. So I decided to just pull this faceplate and put it on the Motorola tube. I used the heatgun and it proved to be the easiest I've done yet. Less than 10 minutes to pop the glass; only slight residue stuck to the faceplate. The PVA actually came off in one piece. Meanwhile, I stuck the Motorola tube in the pool so I can remove the broken glass. It is already progressing nicely-the exposed green pva had turned white within an hour or so. The replacement glass off the C-M tube isn't quite as nice, as it has a lighter tint and some scratches, but then this Moto is a real junkyard dog anyhow.


So, there you go. Swimming pool for green, heatgun for white/gray. Your mileage may vary!