Trimphone 722 Tritium Tube Removal

[FABphones]

I have a few Trimphone Tritium tubes to remove, I will be placing them into none-damaged Trimphones where they are missing, believed removed during the early 1980's Radium scare. These must have slipped through the net. I'll also be taking a few photos to see what I can see, if anything, re a 'glow'.

In places, each tube has various sized dabs of what looks like an orange coloured 'glue', and the tubes are firmly held in place.

Could anyone (2cvbloke?) give me any tips re tube removal without breaking the glass? Dissolving the glue has been suggested but don't want to risk damage or leave any marks.

No photos taken yet, I'll be sure to add some 'before' and 'after' pics.

Thanks.

[twocvbloke]

My dial's tube had suffered a previous attempt to remove resulting in a crack, but the actual glass tube is inside an outer sleeve of what I presume is heatshrink tubing, so that retained any leakage of the tritium gas...

As for my removal, I was just super careful in picking away at the glue points (old and brittle so breaks off eventually) followed by very carefully lifting the tube up away from the glue, it eventually popped free with a bit of a ping, but survived and still has a very faint glow left, though far less than it had when I first got the dial back in 2013...

[RB]

Try usin an exacto knife, and gently pick/chip the glue away

[HarrySmith]

I would try applying some heat to the glue points. Use a hair dryer or heat gun to see if it loosens up. Good luck & keep us posted.

EDIT: In reading the previous post it is stated the tube is wrapped in what appears to be shrink wrap. I would recommend to test that first with heat. It probably won't melt if it is shrink wrap but it may soften & deform.

[andy1702]

From memory... Isn't the tube held in a silvered plastic part, which is a  modified bit on what is basically a dial 21. Is it possible to dismantle the diasl and remove the tube with the silver plastic bit and refit to another phone?

I doubt the GPO/Telecom went to this trouble. They probably just changed the dial. Which makes me think a dial without a tube probably wouldn't be an original one anyway.

[twocvbloke]

From memory... Isn't the tube held in a silvered plastic part, which is a  modified bit on what is basically a dial 21. Is it possible to dismantle the diasl and remove the tube with the silver plastic bit and refit to another phone?

Pretty much, aside from the silvered part, it's a white plastic part in which the tube sits, you could take the white plastic section off that one dial and fit to another, heck, you could probably indeed fit it onto a 21 type. As for the non-tubed versions, I've never seen the inside of those so don't know whether they have or haven't got the same part, I'd assume "have" as it'd be far cheaper to omit the tube than to re-tool the moulds for a new piece...

[FABphones]

Pretty much, aside from the silvered part, it's a white plastic part in which the tube sits, you could take the white plastic section off that one dial and fit to another....

That's exactly what I decided to do. I tried using a craft knife (exacto knife) to carefully cut away the adhesive but it is under the tube so I couldn't get at it enough to free the tube, so I thought it's probably easier just to swap the part out.

Still a work in progress. The sun is out, and Spring has sprung so I have been called off phones at the moment.

Attached photo of Tritium tube insitu.

[andy1702]

Pretty much, aside from the silvered part, it's a white plastic part in which the tube sits, you could take the white plastic section off that one dial and fit to another, heck, you could probably indeed fit it onto a 21 type. As for the non-tubed versions, I've never seen the inside of those so don't know whether they have or haven't got the same part, I'd assume "have" as it'd be far cheaper to omit the tube than to re-tool the moulds for a new piece...

As far as I know, the dial in a trimphone is pretty much the same as a dial 21, except for that plastic bit that holds the tube. I forgot it's white on some of them, but I've definitely got at least one silvered one somewhere. They don't fit this part where there's no tube, it's just like a normal dial 21. My suspicion is that the plastic backing and the tritium tube come as a complete sub assembly, so when they take the tube out they take the plastic bit out as well and replace it with a normal bit from a dial 21.

[FABphones]

I have a couple without the Tritium tube. Until I tried to remove one without snapping the glass I always assumed they had just been removed. Now I believe the complete assembly (tube/grooved section) was swapped out. In view of the scare, I don't think anyone at the time would have been willing to risk handling breakages. My 'blanks' are just the grooved section, no tube, and no sign of adhesive. They probably ordered the part in minus the Tritium tube and did a straight swap. No retooling, cheaper to produce too.

If I open the right ones soonish I will add a photo. I have Trimphone Tribbles here at the moment - 14 of them not including those on display....


Andy, if you find your silvered one please add a photo on this thread, it would be interesting to see what they did.

[twocvbloke]

My suspicion is that the plastic backing and the tritium tube come as a complete sub assembly, so when they take the tube out they take the plastic bit out as well and replace it with a normal bit from a dial 21.

That wouldn't work as the dial is held in place by the outer shell through pressure, if the tube part was replaced with a regular part, the dial would be loose in the case as the plastic section is thicker in height, in the same manner that a Trimphone dial doesn't fit in a 746 as it's too tall for the shell to sit over it...

[FABphones]

From another aspect (I am ex STC), the designers took a huge amount of pride in their work, a Trimphone was pure Trimphone, not a melange of parts from other models.
And from an office/buyer point of view, much easier to continue the relationship with an existing supplier and buy in the part (usually for assembly on site) minus the Tritium tube.

[andy1702]

I'll try to root out my trimphones over the next few days and take some photos. the problem is I've got quite a few of them and remembering which ones don't have the tube or have the silvered plastic bit is a bit like playing Russian roulette!

Back to the tritium tube... Has anyone come up with a good method yet to make the dial glow again? I've heard vbarious things over the years about using LEDs or flourescent paint, but can't recall seeing the outcome of these. I've noticed some dog harnesses on the market include a logo printed with 'light gathering paint' which seems to somehow collect daylight then release it slowly when it gets dark. I can vough for these working amazingly well to illuminate a dog at night, so was wondering if an old tube painted with this stuff would be a very close match for the original? It definitely seems to be the right colour.

[twocvbloke]

I haven't done anything more with my LED lighting idea, lost track of it with dealing with mental health issues, but I have seen people try luminous paint on card placed behind the dial face, only issue with that is needing to keep the phone somewhere with bright light to keep the paint "charged", and how long said paint lasts for after it's gone dark...

[FABphones]

Andy, do you have any from the Snowdon range, these were the later models so I'm wondering if they might be a version issued without the Tritium tube. I'll try and get a moment in the next day or so to take a look in one of my Snowdons. If we could both add a photo it would be a good comparison.
Hope you find the silvered version you say you have, am keen to see what was done to that.

[andy1702]

Revisiting this thread has reminded me to go and search out some trimphones. I'll head for the loft with my screwdriver and go take the covers off a few to see which is which. I've restored a few trimphones for other people over the last year or so, so I'm just hoping the silvered one I'm remembering wasn't one of those. Fingers crossed!

I do have a couple of Snowdens. I've got a red one and a black/grey one somewhere. I'll go have a rummage.