Twin panel tubes adhesive advice please - UK Vintage Radio Repair and Restoration Discussion Forum

ctc15 · 27th Jul 2014, 4:43 pm

TWIN PANEL TUBES ADHESIVE ADVICE PLEASE

Twin panel tubes are ones which have the protective screen bonded to the screen of the tube. Over the years the adhesive fails and becomes opaque often called a cataract and when very bad the screen will fall off as it did with my EKCO CT104, Mikeys tube is still at the cataract stage.
To make these tubes safe to use the screen needs to be re-fixed to the tube. On the U.S. Videokarma web site they say it is P.V.A. but the only P.V.A. I have used is for wood and it is not clear and will not stick to glass.
I have tried silicon which will stick but is not clear. On Videokarma they just put silicon on the edge to hold the screen in place but I have seen pictures where the screen has broken and it seems to plane glass so I think the adhesive is the protection like the P.V.C. bag Fenbridge screen used on some thorn T.Vs about 1964.
Could anyone with knowledge of tube manufacture or re-guning please help.
KEITH

27th Jul 2014, 5:23 pm

We (work) have LCDs bonded to touch screens (saves two reflecting surfaces) by a jelly like substance. Works a treat, try googling screen laminating or the like. Another thought is try gelatine, make a good thick batch, warm tube and panel, stick together. A waterproof edge coating will stop (hinder) the drying out.

Found this a well http://www.uksealants.co.uk/ceresit-...ne!--p286.html

Heatercathodeshort · 27th Jul 2014, 6:12 pm

UK twin panel monochrome tubes have the implosion screen fixed to the CRT faceplate with what looks like some form of silicon. This does not go opaque as the American colour tubes are prone to do.
Any form of organic glue will no doubt break down over an extended period.
I have a number of mono receivers with twin panel tubes and all of them are 100%. The 'adhesive' is soft and has remained so after 50+ years. To put it crudely it has a 'snot' like consistency. Regards, John.

Stylo N M · 29th Jul 2014, 3:19 pm

Hi,

I saw on YouTube where a guy cleaned all the old glue off, after painstakingly working all the way round it from the outside to the middle with a hair dryer to soften the glue, as it hadn't droped off the CRT. Then he refitted the protective screen very precisely with double sided sticky pads placed arround the very edges. Looked extremely fiddly and difficult.

Paul.

AC/HL · 29th Jul 2014, 11:48 pm

I wouldn't want to be anywhere near when that one imploded!

27th Jul 2014, 4:43 pm	#1
ctc15 Pentode Join Date: Oct 2005 Location: Barnet, London, UK. Posts: 167	Twin panel tubes adhesive advice please TWIN PANEL TUBES ADHESIVE ADVICE PLEASE Twin panel tubes are ones which have the protective screen bonded to the screen of the tube. Over the years the adhesive fails and becomes opaque often called a cataract and when very bad the screen will fall off as it did with my EKCO CT104, Mikeys tube is still at the cataract stage. To make these tubes safe to use the screen needs to be re-fixed to the tube. On the U.S. Videokarma web site they say it is P.V.A. but the only P.V.A. I have used is for wood and it is not clear and will not stick to glass. I have tried silicon which will stick but is not clear. On Videokarma they just put silicon on the edge to hold the screen in place but I have seen pictures where the screen has broken and it seems to plane glass so I think the adhesive is the protection like the P.V.C. bag Fenbridge screen used on some thorn T.Vs about 1964. Could anyone with knowledge of tube manufacture or re-guning please help. KEITH

27th Jul 2014, 5:23 pm	#2
Guest Guest Posts: n/a	Re: Twin panel tubes adhesive advice please We (work) have LCDs bonded to touch screens (saves two reflecting surfaces) by a jelly like substance. Works a treat, try googling screen laminating or the like. Another thought is try gelatine, make a good thick batch, warm tube and panel, stick together. A waterproof edge coating will stop (hinder) the drying out. Found this a well http://www.uksealants.co.uk/ceresit-...ne!--p286.html Last edited by Guest; 27th Jul 2014 at 5:24 pm. Reason: brain started to work

27th Jul 2014, 6:12 pm	#3
Heatercathodeshort Dekatron Join Date: Jun 2005 Location: Warnham, West Sussex. 10 miles south of DORKING. Posts: 9,147	Re: Twin panel tubes adhesive advice please UK twin panel monochrome tubes have the implosion screen fixed to the CRT faceplate with what looks like some form of silicon. This does not go opaque as the American colour tubes are prone to do. Any form of organic glue will no doubt break down over an extended period. I have a number of mono receivers with twin panel tubes and all of them are 100%. The 'adhesive' is soft and has remained so after 50+ years. To put it crudely it has a 'snot' like consistency. Regards, John.

29th Jul 2014, 3:19 pm	#4
Stylo N M Heptode Join Date: Jul 2012 Location: Derby DE1, Derbyshire, UK. Posts: 626	Re: Twin panel tubes adhesive advice please Hi, I saw on YouTube where a guy cleaned all the old glue off, after painstakingly working all the way round it from the outside to the middle with a hair dryer to soften the glue, as it hadn't droped off the CRT. Then he refitted the protective screen very precisely with double sided sticky pads placed arround the very edges. Looked extremely fiddly and difficult. Paul.

29th Jul 2014, 11:48 pm	#5
AC/HL Dekatron Join Date: Nov 2003 Location: Heckmondwike, West Yorkshire, UK. Posts: 9,642	Re: Twin panel tubes adhesive advice please I wouldn't want to be anywhere near when that one imploded!