Weller TCP soldering iron

[John HaineParticipant @johnhaine32865]

When I worked at the Post Office Research Department in 1972 Weller irons were "updated" with a small format Belling-Lee plug between the transformer and the iron lead (presumably to add an earth connection for soldering static sensitive devices). Someone pointed out to the safety people that if you had a crowded bench with a mass of mains and other leads one of which had a small Belling Lee mains plug on the end, and it WAS a mains lead, plugging it into the 24 V secondary of a mains transformer might be a bit unsafe. So they tried it, and it was spectacular, 2400V coming out of the mains plug (for a short while). The PO bought a LOT of those irons, I believe Weller changed the design shortly after…

[John Doe 2Participant @johndoe2]

Ah, very handy that I just noticed this thread:

I too used Weller TCP irons professionally for many years, and found them to be very good.

So, naturally I bought a Weller TCP for myself – a W 61 model. But it has a weird fault. Sometimes it works perfectly, but other times, the heating element jams on. The first I am aware of this is a bakelite smell from the iron holder stand and on inspection I can just make out that the barrel is glowing a very dull red !!

I have had the iron in pieces several times and can see that the internal magnetically operated element switch is not welded shut. The switch operates when I remove the tip from the barrel or heat the tip in situ with a blowtorch.

So why does the iron sometimes not shut off? I bought the iron and Weller tips from RS, and of course it is now out of guarantee, but it must be possible to get this thing working. I note Robert's comments about the tips made of two sections, which are the type I have, (no 7 ones). I have tried a couple of tips.

I wondered if the heat from the element is not getting to the tip enough to trip its magnet? is there a heat transfer cream I could use?

Or any other suggestions welcomed.

[Dr. MC BlackParticipant @dr-mcblack73214]

Weller are a long established reputable company as are Radiospares.

I'm certain that the technical boffins in one or the other company will be happy to discuss this problem and give advice.

I have reported problems with items bought from Radiospares long after the guarantee expired and found them VERY helpful.

What have you got to loose?

MC

[Robert Atkinson 2Participant @robertatkinson2]

John,
Your issue is almost certainly a faulty switch in the iron. When worn they sometimes weld closed. a slight knock wil release it and it will work for a while then stick again. New switches are available.

Robert G8RPI.

[John Doe 2Participant @johndoe2]

As I stated above , the switch is not welded shut – that is the first thing I checked – visually. It opens when I withdraw the tip from the barrel, and when I heat the tip with a blow torch.

There is some other reason, that I cannot fathom, except possibly to do with (lack of ) heat transfer from the barrel to the tip.

Edited By John Doe 2 on 01/10/2022 21:16:35

[V8EngParticipant @v8eng]

I had a weller tcp1 at work for many years and from what I remember if trouble occurred it was important to clean the inside of the tube that the tip sits in.

Great irons I still miss it but do very little soldering of that type now and just rely on an old antex.

Edited By V8Eng on 01/10/2022 23:28:31

[peak4Participant @peak4]

Posted by Robert Atkinson 2 on 01/10/2022 19:59:02:

John,
Your issue is almost certainly a faulty switch in the iron. When worn they sometimes weld closed. a slight knock wil release it and it will work for a while then stick again. New switches are available.

Robert G8RPI.

Is the switch part of the heater element, and thus voltage dependent?

Mine has the opposite problem and never heats up unless you shake it for a while, and then only stays hot for a short time. It works when you first power it up, and then cools off immediately.
It's been like that since new; it's ex-BT, as am I, and we were told the feature was designed in as a tip saver.
It still drives me round the bend as it needs re-shaking every two or three soldered joints.
Not a major problem for maintenance folk, who were only changing a component or two, but I was construction and soldering hundreds + connections per day.

The iron itself is a 50V one, hence the query on the switch/heater. I'd consider a replacement iron, but I have loads of spare tips for this one.

Bill

[Michael GilliganParticipant @michaelgilligan61133]

Bill

There is a concise description of its action on the page that I linked much earlier in this thread:

**LINK** http://spritesmods.com/?art=wtcpled

MichaelG.

.

Edit: __ more detail, of course, in the patent:

https://worldwide.espacenet.com/patent/search?q=pn%3DUS3662152A

Edited By Michael Gilligan on 02/10/2022 09:08:29

[peak4Participant @peak4]

Posted by Michael Gilligan on 02/10/2022 09:03:57:

Bill

There is a concise description of its action on the page that I linked much earlier in this thread:

*……………….

Edited By Michael Gilligan on 02/10/2022 09:08:29

Thanks, I missed that.
Since mine is on a simple ¼" jack and separate 50v transformer, I might have an experiment with an in-line AVO and an extension lead with exposed contacts.

Bill

[John Doe 2Participant @johndoe2]

Mine is a W61 – mains voltage. The switch is at the opposite end of the heating tube to the tip, and is operated magnetically. The switch housing is transparent and I can see the switch contacts open and close if I remove the tip or heat the tip with a blowtorch.

The problem has to be lack of heat transfer to the tip from the heating element so the tip is not getting hot enough to magnetically trigger the switch. The barrel and tip both seem clean enough. Is there a heat transfer paste I could use? Never seen it with any of the 48V Wellers I used at work though.

[peak4Participant @peak4]

Well after I'm not sure how many years, I think I've sussed it with my iron.

I've been retired about 8 years now, and had prolonged correspondence with our procurement people whilst I was still at work about this.
It seems either Weller, or my employer, supplied us with an iron with the wrong tip(s)

The one fitted was non-magnetic, and intended for a non-Magnastat soldering station.

Ho hum

Bill

[Michael GilliganParticipant @michaelgilligan61133]

All’s Weller that ends Weller, Bill

MichaelG.

[Robert Atkinson 2Participant @robertatkinson2]

Hi John,

Sorry I missed that you had a W61. This model does not use the two part LT series tips. It needs the CT5 series of tip.
https://uk.farnell.com/weller/ct5c7/tip-straight-3-2mm/dp/834117?st=ct5%20tips
It won't even work properly with the one piece PT tips used by the 24V irons.

I note Farnell incorrectly say on their website it will use PT or LT tips
https://uk.farnell.com/weller/w61-uk/soldering-iron-60w-230v-uk/dp/415807?st=w61
The datasheet says different
https://www.farnell.com/datasheets/1714610.pdf

Robert G8RPI

[peak4Participant @peak4]

Other info available from Weller's own website, about the W61 as well as the type I use, which is where I found the issue with mine.
https://www.weller-tools.com/professional/EUR/en/Professional/Product+lines/WE+Line/W+61

Bill

[Sen HuybrechtsParticipant @senhuybrechts75881]

Hello I was wondering what tips this soldering iron uses. I have the weller type 21 021 magnastat lotkolben TCP (I think this is the same soldering iron as displayed).

Sen

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