Weller Iron overheating?

[ajs37]

Hi - I normally use a Metcal iron, but as I am doing some work on an older radio with large solder joints, I thought I would get out my Weller WTCP51 - haven't used it much, since I got it last year (it's nearly new), so I wasn't too sure what to expect, so forgive me if this is normal behaviour for this iron:

I switch on - use it - it works fine - replace it on the stand - go to use it again and the tip is glowing red (in dim light) and obviously extremely hot! It obviously works brilliantly on undoing any old soldering joints, but it does seem to me to be overly hot - I can't make a decent joint with it! (using 60/40 solder)

The iron itself is a TCP-S, 50w 24volt jobbie - so am I misusing it, or is there something wrong with the iron? Do I need to strip it down? (the iron, not the psu). I didn't get any instructions with it, so I just don't know - but I hope that you chaps can point me in the right direction!
thanks
Andy

[Framer Dave]

If I recall rightly, the tip temperature of TCP pencils is controlled by the tip itself. If your remove the tip, there is a number stamped into the inner end, the higher, the hotter. I think they go up to "9". I've got a TCP24 with one of these in for really serious soldering, but I think I used to use a "4" for small work. I use a Weller WSD81 temperature controlled soldering station now, with an 80W WSP80 pencil.

HTH,

[techiesteve]

I've never seen a Weller iron tip glowing red. I normally use a 700 deg F tip in my TCP24, but sometimes I use a chunky 9. That can burn solder, I'm surprised yours doesn't. Assuming yours is similar to the TCP24 or WD60 I've used, the irons thermostat could be failing.

[dallaslaff]

Hi, The TCP irons use a "Magnastat" thermostat, works on the the principle that the magnetic properties change with temp. The bits, as has already been stated, have a number stamped on the end, the higher the number the hotter the iron temperature. The symptoms you describe happen when the stat fails to open at the right temperature. Tapping the iron restores, at least temporarily, normal operation. The thermostat contacts can be cleaned by taking the plastic cap off the end, this may cure it, replacing it is a better long term solution. However, they're not cheap.
Les

[Ed_Dinning]

Hi Gents, you ca also get this fault if the tip is not clamped in th tube correctly (barrel loose).

Ed

Info... The numbers are 100's of degree Farenheight. A stuck magnestat will cause this problem, we used to use a magnet held againt the outside (defeating the thermostat) to get them hot enough to light our fags.

[kalee20]

I have seen a Magnastat iron glowing red. I took it apart, cleaned it with IPA and an air line, reassembled it, and it's behaved since.

As the Magnastat irons do depend on physical movement of an actuator, there is the possibility of it jamming. But normally, these irons are pretty good.

[Leon Crampin]

These Weller irons are a pest - the thermostats always either jam or trigger the 'scope at the wrong time.

I disconnect the thermostat switch and replace it with a Si diode which halves the power of the element. The loss of temperature control is not really noticeable.

With this modification, bits and elements last longer and there is no interference.

Leon.

[Herald1360]

Dunno that I would be that negative about them, but I do think that the magnastat system did work better on the older mains voltage version. I don't think increasing the switched current by a factor of 10 did the contacts any favours!

[davegsm82]

I've put a bigger cap across the contacts in the past, does help to neutralise the nasty splash when the contacts open (slowly, as they do).

One of the chaps on the board came up with a Triac switched modification a little while ago, nice and simple but effective.

Dave.

[Alistair D]

Weller themselves did a triac version of this iron. It didnt last very long.

Al

[ajs37]

thanks chaps - I will strip it down tomorrow and see it I can 'cure it'!
thanks again
Andy

[fetteler]

I had this very same problem with a relatively new iron (very few hours, but I had had it longer than a year) glowing red. I simply contacted Weller who were extremely helpful and replaced the iron with one that has worked perfectly ever since.
I also have had experience of these Irons being very reliable and providing years and years of faultless service.
Cheers,
Steve.

[Kat Manton]

Originally Posted by davegsm82

One of the chaps on the board came up with a Triac switched modification a little while ago, nice and simple but effective.

Relevant previous threads:

• Weller TCP junk-box mod.
• Weller TCP - prolonging switch life
• Also, Weller soldering station. (Failing to heat, same culprit as for overheating.)

Kat

[QQVO6/40]

In my workshop I have a pedal operated relay to control the mains power to my Weller soldering station. Foot down and just a few seconds later I have heat. Foot off and it soon cools down to be very safe with no risk of fire in my workshop. Really saves on power bill and iron and tip life. I have had my one iron for 15 years, used regularly, still going strong. Pedal switch for the left foot controls the PTT line on my radio gear. Doubly sweet!
Cheers Robert.

[Mike Phelan]

When I worked at Thorn, in the video department, we used Wellers all day, every day, with no problems.

I have one in the outside workshop that I've had for years; couldn't afford a transformer then so a Korting 54660 TV tranny fills the bill.

In the inside workshop I use a Metcal.

[retroguy]

I have a Weller temperature controlled station that was yanked off the workbench by some idiot getting their wheeled chair caught in the iron lead! I contacted Weller UK (it may actually have a different name, can't quite remember), who put me in contact with their service department. A very nice lady told me to send it to her and she'd have a look. If she can fix it, it should cost £20 - if not, she'll post it back to me and not charge a thing. Likewise, if the repair will cost more, she'll tell me and I have the option of saying no and she'll return it for free.

As their prices seem very reasonable, it may be worth contacting them if you have no joy sorting it out yourself.

[G0HZU_JMR]

At work I had a similar issue with a JBC soldering station. These irons are very expensive and have snazzy tips that can be swapped between in about 3 seconds. So really versatile... but...
After about a year mine started glowing orange/red at the whole tip. The first time it did it I thought I must have imagined it because it only glowed like this for a few seconds and was bright orange in a well lit lab!

Then it did it again whilst I was soldering. It went from metal colour to orangy red in a few seconds and then went back to normal again. Freaky stuff!

I asked a colleague who had the same iron and he said "they all do that" and told me to swap out the tip.
I tried this and got the same result a few days later and I then threw the iron away in favour of a cheapo Weller 81 station.

[G0HZU_JMR]

One good tip (pun intended) for owners of the old school TCP51 series irons from Weller is to take the tip out fairly regularly and keep the nozzle hole in the element clear of oxidisation.

i.e. one common cause of failure is the tip seizes in the element and kind of welds itself in there. Often it's impossible to remove it even using mucho twisting with grips and a new element is the only cure.

[Billy T]

Per Mike's comments, this may be some kind of record, but I have been using the same Weller TC201 iron and TC202D supply/stand workstation since the mid 1970s with pretty much the same set of 5 tips of varying tip sizes and temperature ratings. I think only two or three of the more common sized wore out and I've never used any of the more modern solders, which I understand are a little more aggressive. I still have good stocks of the genuine lead/tin 60/40? article.

To be fair, I have replaced the element once, and I had to change the plug that interfaces the iron to the base station after I dropped the base and it broke.

It is certainly more than 35 years though, and for a fairly long period it was in use 6 days a week for up to 8 hours per day. I must say though,that it is no thing of beauty these days, the blue colour is now a sickly green.

Cheers

Billy