Loose crt sockets

[oldtvman]

The one constant I have been seeing is all the roundie crt sockets seem to be coming loose due to the age of the glue used to secure them when they were manufactured. Anybody aware of what type of adhesive they used when manufactured? My guess is it was some type of epoxy.

[reeferman]

Sorry, I thought you were addressing the socket, not the CRT base.

What ever was used is now long gone, for sure. My best results have been using the regular JB Weld. Apply glue to clean surfaces, place the item in the oven, set at 170 degrees. When set-point is reached, turn off oven and allow to cool while in oven. Works every time.

[miniman82]

There was a special cement used to glue the base onto the tube, I don't know if it's made anymore. RACS in France used electronics safe adhesive, similar to silicone just without the corrosives in it. They drilled a small hole, and injected it through the base pin- that's what I would do.

[stromberg6]

Originally Posted by miniman82

There was a special cement used to glue the base onto the tube, I don't know if it's made anymore. RACS in France used electronics safe adhesive, similar to silicone just without the corrosives in it. They drilled a small hole, and injected it through the base pin- that's what I would do.

The special silicone sealant without acetic acid probably isn't a product that you can find on the shelf at your local hardware store. Any suggestions as to where we can find it, I have many tubes that could use it, not just CRTs.
Thanks,
Kevin

[andy]

...

[jr_tech]

Originally Posted by stromberg6

The special silicone sealant without acetic acid probably isn't a product that you can find on the shelf at your local hardware store. Any suggestions as to where we can find it, I have many tubes that could use it, not just CRTs.
Thanks,
Kevin

How about the "sensor safe" silicone sealant sold at auto parts stores?
jr

[stromberg67]

Originally Posted by jr_tech

How about the "sensor safe" silicone sealant sold at auto parts stores?
jr

I'll check it out. Thanks for the suggestion!

And how the heck did I wind up with two names on two different computers?! I'll check that out, too!

[andy]

...

[jr_tech]

Originally Posted by andy

I have bought that before, and it had the same acidic smell that standard silicone has. It may lack other additives that could be harmful though.

Darn, several people here have recommended the "sensor safe" material... and it appears to be MUCH cheaper than Dow Corning 3145, which I believe was used in some CRT factories. Anybody know what the hard orange-brown cement commonly seen in base caps onolder tubes was?
jr

[Tubejunke]

I wouldn't use any kind of silicone sealants. If for no other reason the stuff is not rigid when it cures. They make a world of two part (I guess) epoxy type products like someone mentioned J-B Weld. But I wouldn't have thought of that. I would go for the plastic two part stuff or maybe better yet super glue.

The sockets get loose often from being not so gingerly separated when the set has been worked on. You have to hold the plug on the end of a c.r.t. tightly and gently wiggle the socket off. A shot of WD-40 or any other penetrating oil on the pins helps. If it's still stubborn, you can gently wedge with a medium screw driver working your way around the circumference.

[bandersen]

I use Permatex 81730 Flowable Silicone Windshield and Glass Sealer which does not contain acetic acid and is designed to bond well to glass. It holds the base on tightly but has just a little give to it.

It's my understanding that using a very hard adhesive like epoxy could cause the glass to crack if it has a different coefficient of expansion. Those necks can get pretty hot during operation.

[Kevin Kuehn]

Way down at the bottom of this antique wireless article they give an old RCA formula for "tube basing cement".

http://www.antiquewireless.org/uploa...acuum_tube.pdf

[bandersen]

Coarse marble flour 170 lb.
Orange flake shellac 19-1/2 lb.
Durite phenolic resin LR275-2 7-1/2 lb.
Medium - color (grade G) rosin 3-1/4 lb.
Denatured alcohol 9 liters
Malachite Green aniline dye 10 g.

(Just for reference: the above recipe yielded enough cement to put bases on
23,000 Type 50 tubes. The dye gave a rough indication of curing temperature by
losing its color near the desired 150ºC....

I sure wish I had 23,000 type 50 tubes to try it out on

[StellarTV]

I've had great success for years with clear fingernail polish. Holds up to the heat well.

[marty59]

It had been referred to me by a through a radio/ham guy to use some Elmers white glue. Although you need to allow time to let it set up, I've been suprized by the results. No kidding!