Weller Soldering Iron Tip Problems - not taking solder

[userx2]

Here is a picture of one of my tips.

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This is the replacement temperature magnaswitch I installed.

There is no heat when no tip is fitted. So it appears to be working, at least partially.

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I just measured the station power consumption and it switches between 53 an 4.2Watt.
That means it is switching on and off correctly.

I measured the temperature with an IR thermometer to be around 312degC and 343 with a thermocouple.

Is this correct or is there still a temperature issue?
This tip is no.8

 

[Easy peasy]

You can use a scalpel to very gently take the oxide of an iron tip and then re-tin

always turn your iron down to min or off when not using

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We get 5 + years out of our original Weller and ERSA tips

 

[c_mitra]

Is this correct or is there still a temperature issue?

312-343C is certainly high; anything greater than 300C is not recommended for soldering electronic components.

In one of their videos, they show the working temp to be 500 (should be in F) which is close to 260C. Common solder melts around 200C and pure tin around 230C.

Excessive temp at the soldering tip will cause rapid oxidation of the tin/lead (it will look dull; the oxide will not melt and float on the liquid metal like a thin skin) that will not help in soldering.

Flux used in soldering is a reducing agent but it actually dissolves away the oxide film (both on the solder iron tip and the item to be soldered) but it has only a limited capacity.

 

[userx2]

312-343C is certainly high; anything greater than 300C is not recommended for soldering electronic components.

In one of their videos, they show the working temp to be 500 (should be in F) which is close to 260C. Common solder melts around 200C and pure tin around 230C.

Excessive temp at the soldering tip will cause rapid oxidation of the tin/lead (it will look dull; the oxide will not melt and float on the liquid metal like a thin skin) that will not help in soldering.

Flux used in soldering is a reducing agent but it actually dissolves away the oxide film (both on the solder iron tip and the item to be soldered) but it has only a limited capacity.

Are you sure or am is that theory and I am the only one who has actually measured it?

If correct, then I do have a problem but what can it be?
Everything is working correctly.
Unless they (Weller) actually make (or made) switches with a higher temperature for a different purpose?

Can the switch be faulty in that it is new and operates but not at the right temperature? Hmm.
:thinker:

ACTUALLY:
I just researched this a bit and found that the number on the tip is the temperature in Fahrenheit/100.
That would make my #8 tip 800dF or 426dC !

Looking further, I found this:
https://cdn.sos.sk/productdata/c6/a8/fee5c9ff/tcp-s-t0053210599-1.pdf

The tips there are all over 300degC and what I measured seems to be very close to spot on according to that.

So what now next?

 

[c_mitra]

If correct, then I do have a problem but what can it be?

Honest answer is "I do not know" but there will be some comments.

Temperature measurements by IR remote thermometers or thermocouples should not give error more than +/-1C.

Their accuracy can be easily tested with boiling water or a small piece of ice from the fridge.

Weller is a very highly reputed brand but that does not mean that it cannot go bad.

Their datasheet says "Working temperature selection is achieved by simply changing the "temperature sensing" soldering tip. These are available in temperature ratings of 260°C, 310°C, 370°C, 425°C and 480°C."

 

[Easy peasy]

A "7" tip is general purpose ( 700 F ) larger tips are useful in "6" ( 600 F ) "8" tips ( 800 F ) are not used a lot these days - used to be used on the larger tips when you had something on a larger copper pour to solder - often 2 of them to get the job done ...

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if the magnet part cannot slide freely in the bore - you will have issues - clean it all out as best you can ...

 

[ZASto]

312-343C is certainly high; anything greater than 300C is not recommended for soldering electronic components.

In one of their videos, they show the working temp to be 500 (should be in F) which is close to 260C. Common solder melts around 200C and pure tin around 230C.

Excessive temp at the soldering tip will cause rapid oxidation of the tin/lead (it will look dull; the oxide will not melt and float on the liquid metal like a thin skin) that will not help in soldering.

Flux used in soldering is a reducing agent but it actually dissolves away the oxide film (both on the solder iron tip and the item to be soldered) but it has only a limited capacity.

I must disagree with you.
I use Weller magnastat since 1981. Most used tips are with number 7 stamped at the "butt". This is marking for switching temperature. Numbers spans from 5 to 8 and temperatures are as follows:
5: 500F = 260C
6: 600F = 315C
7: 700F = 371C
8: 800F = 426C

I have a couple of 6-es and these are still in a drawer.
90% of time I use 7-s (regular work) and 8-ts when I encounter high copper masses.

And, yes, I have Tip Activator, just in case, when I forget to switch off my iron for days

Newer tips are much worse quality than before. Deteriorating much faster than older production ones.

 

[betwixt]

I don't remember the number being related directly to the temperature, at least on the early TCP models but higher numbers did equate to higher temperatures. The recommended number for general soldering is '7'.

The manufacturer advised users to tin the tip with solder as soon as it was fitted and turned on. Once a solder layer had formed it would last for a long time but leaving it bare iron would quickly stop it being used ever again.

Brian.

 

[c_mitra]

I must disagree with you.

It is a personal choice but most semiconductor manufacturers recommend a soldering temp of <300C for a period not exceeding 10s. This information is provided in most datasheets.

Of course the effective temp at the point of contact will drop down (say by 5-10C; depends on the local copper heat capacity and the component being soldered) and if you need more than 10s to solder a joint then there is certainly a problem.

Higher the temp the greater and faster is the oxidation (of solder and also of iron) and it becomes more difficult to clean.

 

[userx2]

So unless my replacement magnaswitch is only sometimes faulty, while I am not checking, my temperature is ok.

But the tips still stop taking solder.

Can solder go off with age? I am using the same as always and it used to work fine.

 

[c_mitra]

But the tips still stop taking solder.

Back to square one!

Your soldering iron is able to melt solder fast, right?

Solder balls up and rolls down from the tip, right?

The tip has very few spots that look shiny and silver white, right?

You need to touch the tip to the solder flux (the rosin paste; common solder flux that looks pale yellow or white), solder and steel wool (or the green scotch pad; you clean pots and pans with that; use a new one): in that order.4

Repeat 3-4 times. Touch the tip to the flux; then touch with the solder and clean with the cleaning pad (rotate the soldering iron while cleaning).

Are you using lead free solder? If yes, does it have both copper and silver? Lead free solder has higher melting point and oxidises faster.

 

[userx2]

Ok,
After everything, I ordered that Weller tip activator stuff.

I tried it on 2 tips. It worked in a few spots only. I scraped the other spots with a brass edge and retried several times.
Nope.

I also observed that the tinned spots will start going yellow and then dark agsin in just a minute or 2.
Perhaps the iron is overheating, although it is clicking on and off .

I do not know but I have exhausted my possibilities and will have to buy a new soldering iron now next.

I will not buy another magswitch again for this one.

I have heaps of tips for the Weller and wonder what I can get next.

Any suggestions?

Regards
X

 

[ZASto]

You do not have to buy new switch if it is working.
Temperature of the tip is determined by small "knob" at the back of the tip with a number stamped on it.
Most common tips that I use are No.7, i.e 700F or 370C.
Time to solder a leg of a component takes no longer than 1 to 2 seconds at that temperature.
I use TCP-S since 1981 and have not heath damaged any component.

If someone prefers lower temperatures for soldering, so be it

 

[c_mitra]

I also observed that the tinned spots will start going yellow and then dark agsin in just a minute or 2.

The yellow color is due to oxide of lead; the black form is some lower oxide (lead oxide mixed with lead). The black form does not work with the flux. Once it has turned black, scraping with brass wool or vigorous rubbing with a scotchbrite scrubber is the only option.

There is nothing in the solder that can or does go old. The flux core does get oxidised in air (and turn darker in color) but does live happily within the solder shell for a very long time.

Many solder (old) look very dull but that does not affect solderability. Is the tip too rusted? (can make out with a regular magnifying glass)

 

[userx2]

I am not sure what you guys are trying to tell me.
The tips I have are 7 and 8s.

Once the solder goes dark again, the tip stops taking any solder. Sponge does not help and it needs fizzing in the tip activator again.

I never had any issues for a decade with this iron but now I am pulling my hair out.

 

[c_mitra]

The tips I have are 7 and 8s.

These are obviously heavy duty tips and are supposed to get very hot.

Weller tips are not cheap (they can cost an arm and a leg) but a tip labelled 6 would have been best.

Iron does get rusted and need to be stored carefully.

 

[ZASto]

%<
Weller tips are not cheap (they can cost an arm and a leg) but a tip labelled 6 would have been best.
%<

In my country price for Magnastat tips is ~7.5€, so it is not "arm & leg" if you do not abuse them they will last for years.

For my routine, #6 are a little on cold side

 

[c_mitra]

In my country price for Magnastat tips is ~7.5€, so it is not "arm & leg" if you do not abuse them they will last for years.

It is relative; the base price in my country is also very similar but with taxes and shipping it becomes close to 18 euro.

But a copper rod, (about 5gm) with a small iron-nickel disk at the fat end and the tip, the business end, electroplated with iron, costing 7.5 euro is incomprehensible.

Soldering irons are very useful in making small holes in plastic boxes; neat and fast. Never had any problem.

By the way, recommended temp for soldering electronic components is close to 300C (at the solder junction). You may allow 10-20C for the thermal resistance (just a guess value). You shall need higher temp if you are soldering heavy items.

 

[ZASto]

It is relative; the base price in my country is also very similar but with taxes and shipping it becomes close to 18 euro.

But a copper rod, (about 5gm) with a small iron-nickel disk at the fat end and the tip, the business end, electroplated with iron, costing 7.5 euro is incomprehensible.

Soldering irons are very useful in making small holes in plastic boxes; neat and fast. Never had any problem.

By the way, recommended temp for soldering electronic components is close to 300C (at the solder junction). You may allow 10-20C for the thermal resistance (just a guess value). You shall need higher temp if you are soldering heavy items.

Just repaired a couple of mining power supplies (1650W), and was lazyto change tip from #8 to my preferred #7, desoldered - tested - soldered back cca. 15 SOT-23 transistors per each supply with 400+C
All transistors are still working perfectly.
So, it's not tool, it's skill and routine.

And, yes, still using 60/40 solder and rosin diluted in MEK (evaporates faster than isopropanol/ethanol).

 

[c_mitra]

still using 60/40 solder and rosin diluted in MEK

RoHS guidelines recommend /suggest that you avoid toxic components in consumer products; Yes, I know that 60/40 solder has melting point less than 200C (around 180C, I think) and lead free solder is around 220C, but should not be a problem (does not need great skill).

Same way, MEK is more toxic (compared to isopropanol and ethanol) and is not recommended for electronic work. Please have a look at the EPA report: https://cfpub.epa.gov/ncea/iris/iris_documents/documents/toxreviews/0071tr.pdf

Toxic effects of Lead are well known (Romans used lead pipes to carry drinking water). Most major manufacturers are now offering Pb-free products and you are simply trying to defeat the global effort.