Weller Soldering Iron

[GRAHAM99]

I have bought for a few quid in a cash converters a Weller soldering iron.
It says on it Weller TCP 24v 45w.
The lead on it has a blue and brown wire at the end but I take it it would be wrong to just put a plug on this and plug it into the mains?
Does it need a transformer?

[Folderol]

DON'T DO THAT

It's a 24V iron so needs at least a transformer.

[Sam Spoons]

You definitely don't want to put a mains plug on it, you'll destroy it for sure and quite possibly kill yourself in the process.

I sounds like it's designed for use with a solder station but I may be wrong about that.

[Pippacairn]

Hi,
This model is designed to connect to a soldering base station, as new they are supplied with a Bulgin type connector to suit.
Do not connect to the mains under any circumstances.

[DGL.]

Also the temperature setting is done by changing the tip, using a magnestat to control the temperature. If you do get a transformer (24V 50VA should do i think) and the iron dosn't work then a failed magnestat is a common issue.

[GRAHAM99]

I don’t think this should have been sold like this as it really looks as though it just needs a plug attaching!!
Good job I asked….

[Hugh Robjohns]

Well, replacement irons are available on their own, but its not usable without a suitable transformer base station (eg. P-51)... which are also available...

[ef37a]

Hi Graham, I looked after about 100 of these for the best part of five years and there are several traps for the unwary, firstly of course NO NOT apply the mains to it!
Has it got a tip? If so it must have the retaining sleeve and this is secured at the base by a knurled collar or, on earlier ones , a nut shaped collar. This should only be finger tight but rarely are! Use pliers if necessary but once you get it started try to finish removal by hand, if the tube gets crushed you will have problems.

If you get the tube off, the tip will be retained lightly by the magnetic switch and so push the tip down and you should feel light spring pressure, but not end of world if stuck. If a load of white powder comes out the heating element is surely toast. You can get all the parts for these irons but further work is quite tricky and the parts quite expensive so, up to you how far you want to go. (Cooper Tools used to be the agents in UK)

As said, the iron runs on 24V AC but they are not fussy, have run one on a car battery, just takes longer to reach operating temperature so any odd supply you have around that can deliver 12 to 25 V at 2 amps or more will serve. The tip will have a number on its base. 7 is ok for Lead solder but 8 will be needed for Lead free and then only for relatively fine work. A number 9 will be a whizz on Pb free but take care, they are close to the ignition point of paper!

Tip, don't clean with damp sponge as used to be supplied. Brass wool or kitchen paper.

Dave.

[GRAHAM99]

Hi Dave
Many thanks for this.
The iron is just as you have described with a 7 on the base of the tip.
I have always wanted a Weller soldering iron but don’t do enough soldering to really justify the cost!!
I only paid three quid for this in a cash converters shop but luckily I saw the 24v on the base,I was just about to put a plug on it,it looks as though it has been prepared for a mains plug!
It came in a Cooper Group cardboard box.
I have a transformer which looks like one from a train set which gives 16v at 14va but I doubt this would be ok?
Could I just buy a suitable adapter without going to the expense of a proper Weller one?
Thanks again
Graham

[GRAHAM99]

Can the power supply be dc?
Bit of a novice with this stuff!

[ef37a]

Can the power supply be dc?
Bit of a novice with this stuff!

Never had a problem with it. You could first cold check, the resistance should be about 12 Ohms maybe less stone cold. If it reads O/C bounce it on the tip gently, the switch may have stuck. N.B. They will read O/C without a tip.

You can use any supply less than about 25V to test it, you might bugger the supply, won't do the iron any harm. Got an old laptop charger around?

If the iron works you can order a 24V/2A toroid from RS comps say. Note, even if the transformer does not require an earth the case should be and the iron tied to the earthed case with a resistor of about 100k for static protection.

Dave.

[Mike Stranks]

I have a transformer which looks like one from a train set which gives 16v at 14va but I doubt this would be ok?

Correct.

I think we need to unpack this stuff about power-supplies a bit more...

Dave has suggested that a 24volt, 2 amp supply would suit. That's 48 va (watts)

He's also pointed out that he's used a car battery for such duties in the past. That's a notional 12volts DC, so you need 4 amps to reach the 48 va. Fortunately a car-battery is quite capable of delivering such currents.

The crucial thing with any power-supply - mains/transformer or battery - is the current they supply. Matching the voltage is fairly straightforward, but the supply must be able to supply the required current.

So... looking at your existing transformer... we're good on the voltage as Dave has said that 12 volts is adequate. However we're way down on current... the device you specify is only capable of delivering 14va - 0.875 amps - way down on the 3 amps that would be required with a 16-volt supply.

Just a final note... the rated va/amps/watts of a supply is the maximum it can deliver. So a 5 amp supply with something that needs 1 amp is fine. OTOH a 1 amp supply with something that needs 5 amps will end in tears...

[Wonks]

Can I just point out that it's going to be much easier to buy a cheap temperature-controlled soldering station than faff about with trying to rig up a power supply for a fixed temperature iron that may not even work to start with. Unless you are going into manufacture, then you don't need anything too sophisticated. Like guitars, it's nice to have a custom-shop Les Paul or Fender, but the basic Squier and Epiphone versions still get you most of the way there.

Put the £3 spent down to experience.

[MarkOne]

Can I just point out that it's going to be much easier to buy a cheap temperature-controlled soldering station than faff about with trying to rig up a power supply for a fixed temperature iron that may not even work to start with. Unless you are going into manufacture, then you don't need anything too sophisticated. Like guitars, it's nice to have a custom-shop Les Paul or Fender, but the basic Squier and Epiphone versions still get you most of the way there.

Put the £3 spent down to experience.

^^^ This.

I had a Weller for decades but year before last the power supply gave out on it. I didn't even look at getting a replacement PSU (well over £100) For the limited amount I do these days I opted for one of these https://www.amazon.co.uk/dp/B07X3CZ3FJ/ ... UTF8&psc=1 which I think I got it on a Black Friday deal for well under £40, and it's fine. Works pretty well, actually.

Just think of it this way. You could probably have spent more on a Latte in a boutique barista or a large Pinot Grigio , or something equally temporary or disposable.

[ef37a]

Can I just point out that it's going to be much easier to buy a cheap temperature-controlled soldering station than faff about with trying to rig up a power supply for a fixed temperature iron that may not even work to start with. Unless you are going into manufacture, then you don't need anything too sophisticated. Like guitars, it's nice to have a custom-shop Les Paul or Fender, but the basic Squier and Epiphone versions still get you most of the way there.

Put the £3 spent down to experience.

PRACTICAL as ever Wonks! Maybe Graham just wants a bit o fun and messin?

You are quite right. Google will give you many options for T controlled stations. I had a "Duratool" one for some years (I had run out of Weller spares for free!) That eventually broke now use a "Yihua" 937D. Neither as good as the maganastat but very serviceable and WAY better than the ancient Antex!

Dave.

[ef37a]

Can I just point out that it's going to be much easier to buy a cheap temperature-controlled soldering station than faff about with trying to rig up a power supply for a fixed temperature iron that may not even work to start with. Unless you are going into manufacture, then you don't need anything too sophisticated. Like guitars, it's nice to have a custom-shop Les Paul or Fender, but the basic Squier and Epiphone versions still get you most of the way there.

Put the £3 spent down to experience.

^^^ This.

I had a Weller for decades but year before last the power supply gave out on it. I didn't even look at getting a replacement PSU (well over £100) For the limited amount I do these days I opted for one of these https://www.amazon.co.uk/dp/B07X3CZ3FJ/ ... UTF8&psc=1 which I think I got it on a Black Friday deal for well under £40, and it's fine. Works pretty well, actually.

Just think of it this way. You could probably have spent more on a Latte in a boutique barista or a large Pinot Grigio , or something equally temporary or disposable.

Yes, yes, ALL very logical (but not very green) but some of us LIKE 'king about with stuff and have odd transformers and PSUs kicking about.

Dave.

[GRAHAM99]

The iron has a resistance of 13ohms.
I have a power supply rated at at 18.5v and 3.5a dc
The input says 240v and 1.5a
I think it is off a laptop so should be ok?
I do like messing about with this stuff!!

[ef37a]

The iron has a resistance of 13ohms.
I have a power supply rated at at 18.5v and 3.5a dc
The input says 240v and 1.5a
I think it is off a laptop so should be ok?
I do like messing about with this stuff!!

Yeah give it a go, don't burn your fingers!

Dave.

[GRAHAM99]

Just tried it and the iron got hot!!
Will try soldering with it later.
Thanks for all your help on this.
Could be a good three quids worth!
Just need to rig up something permanant between the power adaptor and the iron.

[ef37a]

Just tried it and the iron got hot!!
Will try soldering with it later.
Thanks for all your help on this.
Could be a good three quids worth!
Just need to rig up something permanant between the power adaptor and the iron.

Good oh! Now you have it cooking, bit more distilled wisdom! The best way to clean the bit if it is blackened is to get the iron up to temp and try to melt some solder with it, keep wiping with kitchen paper or cotton (not wool or plastic!) cloth and it should get clean. If not, the very lightest rub with wire wool or you can buy a tip cleaner paste. Works a treat but is pretty aggressive and will wear through the iron plating eventually rendering the tip U.S.
If you start working the procedure as told to me by Weller technical chaps is. "Tin tip, wipe, tin again, solder and when done, for a bit, tin and leave. Before you shut down, wipe the tip and flood with solder, leave to cool. This all will prolong the life of the tips especially the very fine ones. Don't leave the iron cooking all day! It only takes 30 seconds or so to get to op temp so switch off when having a break.

I 'might' have some spares, will let you know.

Dave.

[GRAHAM99]

Got it melt some solder!!
I have rigged up an old guitar footswitch with a socket for the laptop power supply plug and a jack socket for the the iron.I have put a jack plug on the wires coming from the iron.
I think the temp controll works by the properties of magnets at different temperatures?

[ef37a]

Got it melt some solder!!
I have rigged up an old guitar footswitch with a socket for the laptop power supply plug and a jack socket for the the iron.I have put a jack plug on the wires coming from the iron.
I think the temp controll works by the properties of magnets at different temperatures?

Yes the Curie point. The magnet is in the tube in the iron and the base of the tip made of a ferrous alloy that loses its magnetic properties at a certain temperature. Clever or what?! Very little to go wrong. Yes, the switches do fail but only after maybe a million cycles. The heating element, because it is low R and robust hardly ever fails. In fact most of the irons I junked were buggered by Homo sappy!

Dave.

[GRAHAM99]

I tried using the Weller iron to remove a jack socket from a guitar but it would not melt the solder.The tip is a number 7.
I then tried my other “cheap” iron which did melt it.
The Weller will melt some lead free solder I have.
Should I get some other tips for the Weller?

[Wonks]

Lead-free solder has come in quite a few varieties in the past. Current lead-free solder is quite workable compared to some older stuff, which often needs much higher temperatures and the addition of flux or more lead-free solder to start the melting process. I’ve come across one lead-free joint that I had to adjust my temp-controlled iron to maximum for, before it melted.

In addition, your iron with that PSU has approximately a 26W output, so is running at 57% of its nominal 45W rating.

It’s probably a combination of things.