another cat removal
 

this time with water. a 21FJP22. I picked up a small kidde pool (baby really) at target for 5$ fits just right. I don't have my camera handy but will snap a pic later. I used a exacto to cut the tape seam righ at the lens, then peeled it off. the pva as not as hard as I have on some other sets, more like cheddar cheese, maybe ti will go a bit faster than the last one I did (a RCA rectangle, the PVA was much harder on that one. I did that one with the low temp low pressure method. Hopefully the somewhat softer pva will let the water soak in and do its thing in not too many days.

I have the water just above the glue line. I can see that I will have to keep an eye on it for evaporation losses. there is also a bath cloth under the lens, I dont think its needed since the plastic liner bottom shoule be enough to protect it from scratching. I have it on a concrete covered porch.

here it is

give it awhile and it will pull right off.i think this is a much safer way than the heat method.good luck

yea after that report of the failure, I decided to hold off until a better method was tried. I like this one the most.

I was going to to the low heat (out in the sun and low pressure from chop sticks) like I did on the last one, but honestly I was concerned about some dopey kid chucking a rock from the back yard (it happens) an then I would end up in jail... so this seems the best and def the safest for the tube.

it took mine 2 months to fall off, i would try and get it a spot in the garage. There is no way I would let it sit outside that long.

The clear silicone worked out very well. The thing is super strong and sealed for life.

being a man of "science" I plan to add some yeast to it later. hmmm I wonder if a CRT weighs the same as a witch...

Update:

been about 10 days, I lifted it up and applied some pressure (finger nail under the lens) I could see some sign of release at the very edge, the pva was coming loose from the CRT face. Just a tiny bit mind you, but progress none the less....

I'm anxiously watching your progress. I've got two round color crt's that are in need of safety glass removal and I decided a long time ago I was not going to risk the destruction of the tubes (or myself) by using localized heat to pry off the mask. I've got my kiddie pool all ready to go and am waiting for the weather to finally warm up a little bit here in the North East.
Bob

If the PVA is indeed polyvinyl alcohol "PVA", then water solubility is really the only way to go. It essentially turns gummy after a while. If you can get some water circulation going it would certainly speed up the process. (a small aquarium pump directed at the PVA might help).

I used the same method on an oddball 15' rectangular(thick neck) crt from a conrac monitor,took awhile,but it worked.
Pat

agitation, I will see what I can do on that, will look for a small cheap pump.

I was also thinking of some tooth picks stratigically placed around the edges too apply a tiny bit of pressure, and open up the pva to more water.

The water does not dissolve the PVA in any way. It just somehow causes it to unstick to the glass.
The PVA sheet from the one I removed was in good shape. It didnt dissolve at all.

It's actually of the family of Polyvinyl Acetates - kinda like fancy elmers or wood glue.


Later they used polyepoxides - no cutting through that stuff! Patent 3,265,234 from Union Carbide spelled the death of PVA resins, I imagine.

Cheers,

I may keep the mounting hardware on mine to keep it elevated up a bit. Then I can watch for the glass to fall off! :D

Polyvinyl acetate is soluble in VOCs... I wonder if acetone might help then. (or ether if you can get it, but it's a little less "safe" to work with.)