Solder frustration, hard to melt

[FireHazard]

I'm starting to avoid even basic projects that involve any kind of soldering as I seem to struggle with every joint.

I don't really know how to describe it but even on very small boards the solder does not want to melt very easily and when it does it doesn't wet/flow onto the pad/part.

I've tried flux pens, rosin flux brushed on etc. I am using tin/lead solder with 2% flux. I've tried a few different diameters.

The solder melts nicely if i touch the tip of the iron directly, away from the part and board...but when all three are together the solder takes several seconds to melt...and doesn't really want to flow on to the part/board but tends to want to ball up on the tip...

I've watched videos, started with the basics, tried a few different size and shape tips.. etc.

I'm using a Horusdy 882D solder station, which I've had for a few months and purchased based on some good reviews. I've completed a few projects with it but it's been a painful slog from start to finish. Using random flux I can buy here along with random tin/lead solder I can buy locally.

I don't know what else to try...   

[ataradov]

Among all this, you did not mention the type of solder, what temperature setting  and what tip you are using.

[Ian.M]

Cut a novice some slack! The O.P. mentioned they are using locally obtained "tin/led" solder with 2% flux core, but probably doesn't know that any Sn/Pb solder composition more than a few percent away from the Sn 61.9% / Pb 38.1% eutectic is unsuitable for general electronics work.  I strongly suspect they have Sn60/Pb40 solder, (or at least solder labelled as such).

@FireHazard,
Please post closeup pictures of your soldering iron tip, the board you are trying to solder, and any labels on your reel of solder (as we need to confirm its (claimed) composition).  Also, what temperature do you have the solder station iron set to?

[JustMeHere]

Bigger tip, more heat, flux can help.  Also try melting a bead of solder on your bigger tip and applying that to what you're trying to melt. 

I favor the Bevel or C-series Tips. 

Use the biggest tip you can get into your work area.
Heat?  Hotter can be faster, and cooler....how?  You only heat up the area you touch if you're hot enough and fast enough.

Oh yeah, give the iron a good 5 minutes to heat up if it's not an "instant on" type.

[FireHazard]

Cut a novice some slack! The O.P. mentioned they are using locally obtained "tin/led" solder with 2% flux core, but probably doesn't know that any Sn/Pb solder composition more than a few percent away from the Sn 61.9% / Pb 38.1% eutectic is unsuitable for general electronics work.  I strongly suspect they have Sn60/Pb40 solder, (or at least solder labelled as such).

@FireHazard,
Please post closeup pictures of your soldering iron tip, the board you are trying to solder, and any labels on your reel of solder (as we need to confirm its (claimed) composition).  Also, what temperature do you have the solder station iron set to?

Thanks Ian,
     Yes, unbranded generic stuff. Pics attached. Trying with two different tips... I covered them with a good deal of solder before letting them cool...

I've been generally setting the solder station to 350 C..... but it claims to be able to go above 400 ...

EDIT: As far as tips go, i've tried a few different types that came with the solder station... so again, fairly generic..

[David Aurora]

Ignore the numbers on your station and adjust until it works as expected. You could definitely buy better solder as well, but most likely your issue is just that your actual soldering temperature isn't what your display is telling you. Maybe it's not calibrated properly, maybe it's dropping a lot on contact, maybe your tip sucks, maybe the numbers are bullshit 

[Siwastaja]

>Horusdy 882D
Neverheard, google finds no results.
>(picture of the tip)
Tip is too small.

Soldering iron is pretty important, random Chinese junk sometimes work fine but sometimes unusable. That no-name solder also makes things worse, but I don't think it's the main culprit. I would vote for a bad iron.

[ataradov]

Another possible thing is that it actually goes to 350. At that temperature rosin flux will burn out really fast, and the solder will not flow as well. Adjust it to 320 and see if it still easily melts the solder without anything else, then try that.

It is very hard to tell what may be wrong without looking at what is going on.

Also, that conical tip is garbage, no idea why they even bother making them. The other tip looks workable.

And yes, I assume it is a typo. There are 0 search results for "Horusdy 882D".

[bdunham7]

The solder melts nicely if i touch the tip of the iron directly, away from the part and board...but when all three are together the solder takes several seconds to melt...and doesn't really want to flow on to the part/board but tends to want to ball up on the tip...

It's likely not getting hot enough.  Your 60/40 solder will melt at about 190C (if it is what it claims to be) but you need to get it a bit hotter to wet the PCB.  So your iron could be way too cold and the solder would still melt and stick to it, but you'd be unable to transfer enough heat to the board.  Try turning your iron all the way up and see if that helps.  Use the first tip that you show (the bevel) as the other one is too fine for anything other than small work.  Neither one looks great, frankly. 

[Ian.M]

I agree with the others that the thin pointy tip is going to be useless for larger joints as it simply cant conduct enough heat to the tip fast enough. There aren't many good uses for something like that apart from dead-bugging QFN or reworking 0402 or 0201 'flysh!t' passives.   The bevel tip in the first photo looks reasonable. 

The Duratech brand solder wire is more likely to be the 'good stuff' than the Xiau Huang Ren one, as it claims to be an Australian brand (albeit made in China), and has the alloy composition on its label.  I'm always suspicious of solder that isn't labelled properly, as Lead is a lot cheaper than Tin, and there are legitimate (non-electronics) uses for higher Lead content solder, so an unscrupulous seller/exporter may sell you e.g. Pb60/Sn40, (as "60/40") and claim they had no idea that you wanted electronics grade solder rather than something to repair a vintage car radiator with!

Siwastaja's comment about the iron is notable.  The most likely cause of problems here for Hakko clones and similar style irons is the fit of the tip over the ceramic element.  Too big an air gap results in poor heat transfer, but you need a tiny gap as the tip must still slide on and off the element easily as if it seizes on the element due to expanding metal oxides inside the tip cavity, you will most likely break the element trying to get it off.  Genuine tips and elements are made to closer tolerances.  You can try shimming between the tip and element but that can be a PITA when changing tips, and if you close up the gap too much risks the tip seizing.

[JustMeHere]

If you're using external rosin, don't worry about the whole "got to melt it all together at the same time" theory.    Load up you tip with as much solder as it will hold.  Rub some of that paste you have on your joint.  Then stick the iron on there.   It can help to pre-tin your joints too.

Go get an old PCB and practice on it.  Try taking small components off first.  Then go for larger.  Don't be afraid of messing it up.

[tooki]

…
The solder melts nicely if i touch the tip of the iron directly, away from the part and board...but when all three are together the solder takes several seconds to melt...and doesn't really want to flow on to the part/board but tends to want to ball up on the tip...

That is quite indicative of the workpiece not getting hot enough. Use a bigger tip, and make sure it’s got a fresh “pillow” of solder on it as a thermal bridge to the workpiece. Oxidized solder on the tip, and/or an oxidized tip, conduct heat FAR worse.

Watch this video series: https://www.youtube.com/playlist?list=PL926EC0F1F93C1837

It’s hands-down, by a wide margin, the best soldering tutorial I have ever found. It’s worth the time, your soldering will improve through it.

I would also try some top-quality name-brand solder, like Kester, AIM, Indium, Multicore/Loctite, Felder, ChipQuik, MG Chemicals, etc. (Kester remains my all-time favorite.) Chinese solder is all over the place, and there are many reports of people finding that it simply won’t flow. (Rumors are that some of them are cheaply recycled solder.)

[macboy]

Definitely buy some Kester "44" in 63/37 or 60/40 alloy (if you can find it, 62/36/2 is even better, with 2% silver). For through hole work, 0.020" to 0.031" (0.5 to 0.8 mm) works well. A company called NTE sells repackaged Kester solder in a small "pocket pak" so you can buy just a small amount for around $5 or less. Search part number 83-7145-0415 for example. Kester alloys are top notch, and more importantly, 44 flux is just simply amazing. As long as you don't mind cleaning up the Rosin residue, I can see no reason for a hobbyist to use anything else.

If you use that solder/flux combination, then you have definitively eliminated the single most important variable. So if it still doesn't work well, you are pretty much down to either the equipment or technique.

[Bud]

Start from saving you frustrations and only buy known brand solder. Kester is a good choice. It is more expensive but a roll will serve you over huge time period.
Secondly, your iron tip is too small for general work.

[DavidAlfa]

Cheap solder forms a terrible mess with a texture resemblying sand.
Nowadays most solder emits obnoxious fumes and you have to pay them with human organs, so I usually buy old 60/40 rolls for cheap at 2nd hand plataforms, last year I got 1KG for just $10!
It's the old solder everyone will remember from 25 years ago, before the Rohs, with fumes that aren't irritating at all.

[IanB]

Since no-one else has mentioned it, I have that very same solder flux you pictured, and it should be fine. Just for confirmation.

As others have said, your problems are most likely with the temperature, the size of the tip, and the solder.

[DavidAlfa]

Seems a combination of low power, wrong tip (Use a decent sized tip) and/or low temperature (360°C is usually a good spot).
Don't expect to melt a large piece with a needle-like tip .

[tooki]

Seems a combination of low power, wrong tip (Use a decent sized tip) and/or low temperature (360°C is usually a good spot).
Don't expect to melt a large piece with a needle-like tip .

The temperature setting really depends on both tip size, thermal mass, and responsiveness of the soldering station. With my Ersa i-Con nano, or the big i-Con at work, or the JBC at my old work, using an appropriately sized tip, leaded soldering can often be done at 290-300C. Heck, at the place with JBC, we only used lead-free and we were not permitted to go above 350C, and even that was frowned upon.

With that said, I doubt the OP’s station is one that is good enough to use such low temps.

[Ian.M]

For many years Weller supplied a PTAA7 bit as standard with their TCP Magnastat range of irons.  The Curie point slug on the back of that tip set the temperature to 700°F (~370°C)  and many thousands of workshops used that tip as their default for through-hole soldering and rework with Sn60/Pb40.  You could leave an TCP iron running at 700°F on all day six days a week without burning up the bit, provided you wiped and retinned after every break you took, but the PTDD8 800°F bit we kept for big terminals needed to be shut off within five minutes of inactivity, or it would become a total PITA to re-tin

IMHO 370°C  is still a good starting point for cheaper solder stations that may have questionable thermal recovery - its a good compromise between getting enough heat into the work quickly enough, and not burning up the bit during extended inactivity (on stations without in-stand setback).

[FireHazard]

Thank you, something like this?

https://nz.element14.com/kester-solder/24-6337-8802/solder-wire-63-37-sn-pb-183-c/dp/1162176

I'm based in New Zealand...and getting *anything* that one simply takes for granted elsewhere in the world is a drag.

[FireHazard]

So after some experimentation using the fantastic input from this thread, i've found that I need to set the station all the way up to about 410 degrees to get 'melty' flowing solder that I can actually do something with.

Is my journey to soldering just going to be a lot less painful if I go and get an FX951 or something?

For larger context, I'm not totally new to soldering, I've completed a number of projects of the years, the last being a recap of a pair of studio monitors, but it's always been a hard uphill battle (particularly on that project where the PCB had some fairly heavy traces). 

[Ian.M]

You need to get some idea whether the problem is the solder station is out of calibration or if its a heat delivery problem cause by excessive clearance between the element and tip.  For the former, assuming you don't have a soldering tip thermocouple thermometer, probably the easiest is to use the melting point of pure Lead: 327.5 °C.  Cut a very narrow strip from some soft lead sheet (soft lead is probably pure enough to have a melting point  close to  327.5 °C, as most impurities in concentrations that would significantly affect the melting point make lead significantly harder), dip it in flux and use it like solder to 'tin' the bit three times to remove traces of real solder etc.  Leave some on the bit and turn the iron down slowly till it just solidifies, then turn it up till it just melts.    A wooden toothpick dipped in flux is useful for prodding the blob of lead to see if its molten.  That should give you a pretty good idea if the station's temperature readout is anywhere near correct.

The bit should be a close but free-sliding fit on the element for good thermal transfer.  If its too loose, it may be worth trying to source a genuine bit from whatever Western manufacturer the iron was cloned from, as unless the element is seriously undersize, it should be a much better fit.

[bdunham7]

Is my journey to soldering just going to be a lot less painful if I go and get an FX951 or something?

Yes absolutely.  A very long time ago I struggled with electronics soldering (I was good at pipes and radiator, even using irons) until I got an Antex 50W temp-controlled iron (now sold as the TCS50W, but unfortunately for me only in 230V trim) and then suddenly and magically, I could solder. 

So, IMO, the minimum for doing decent soldering is a basic temp-controlled iron or station that has good quality tips.  Antex (irons) and the Hakko FX888D are examples--these are the least I would consider but there are other good options in the $100 (US) bracket.  Next step up would be the basic T12/T15 cartridge-style irons, like the FX951, KSGER, etc.  Then you can spend more and more, but those upgrades will be incremental compared to that first leap from absolute crap to a real tool.

Your little tub of gelled flux is fine, but I'd also get some brand-name eutectic solder.  I can easily manage either way, but for delicate or mechanically tricky operations eutectic is so much nicer to work with that I don't mind paying $$$ for a spool.

[rhb]

I got sucked into the temperature controlled iron BS until I bought a couple of temperature controlled irons.  That is all it is.

The solder joint won't form properly until the *connecting* parts are hotter than the melting point of the solder.  That requires that a certain number of calories flow from the iron into the parts to be soldered.  Otherwise you get a "cold joint".

A small, low temperature iron tip takes a long time to transfer enough heat.  A small *hot* tip drops in temperature quickly as the heat flows into the joint.  That minimizes part heating.

To make the connection quickly you want the iron to heat the parts quickly.  That requires that when the heat flows from the tip into the parts  they  all become sufficiently hot to melt solder in the least amount of time possible.

The specific heat of the solder doesn't vary such that a few degrees above the eutectic matters.  What matters is how many calories does the tip hold relative to what's needed to make the connection in one second or less.  That's my standard.  Touch the iron, touch the solder and remove iron and solder to let the joint cool.  However, it *does* require being in practice as is the case with most manual skills. So I'm not very good if I'm soldering a few connections a month.  But after an hour or two I'm running full speed again.

This is Intro Physics 101 level thermodynamics.  Temperature matters in a reflow oven where everything gets heated.  Hand soldering done properly doesn't heat the part significantly because as soon as the solder melts you remove the heat source.

I have gone back to a traditional industrial fixed wattage grounded iron with a wedge tip.  When it's difficult to make good contact with the iron a *tiny* amount of solder will improve the thermal transfer rate.  Other than that, you don't want solder on the tip.  That's why people use some type of tip cleaner.  I prefer a piece of wet cellulose sponge most of the time, but have a copper scouring pad tip cleaner also if I need it.

Suggestion for the OP.  Take some short pieces of 24-26 AWG wire and twist the stripped ends together to form practice joints.  Line them up so you can immediately go from one to the next.  Practice on those until you can make the connection in less than 1 second.  Try different tips, solder sizes and temperature settings  including maximum setting.

Have Fun!
Reg

[Doctorandus_P]

Start by buying a bit of solder from a trusted and known good brand.

You can also do a temperature calibration very easily, by sticking a blob of solder to your iron, and then twiddling with the temperature knob to figure out where it just melts. Eutectic alloys go from solid to liquid quite fast, while the more it deviates from the "perfect alloy" you will get a pasty like solder between liquid and solid.

Also, heat transfer between a soldering iron and the stuff (on a PCB?) to be soldered can be sketchy. My preferred method is to put a tiny bit of solder in between the soldering iron and the thing to be soldered to improve the heat transfer, and then add more solder directly to the thing to be soldered (without the solid solder touching the iron). The reason is to reduce the speed with which the flux cooks off. Once the flux is cooked off, the solder will not wet anymore.

It's also possible that your iron is simply faulty. For example when the mechanical connection between the heating element and the tip of the iron is bad, then the tip does reach the normal soldering temperature, but once you actually start soldering it's temperature drops quite rapidly as it's cooled by the cold mass touching it and you can't solder properly with such an iron.

There are quite a lot of variables which have to work together for a soldering process to work properly, and experience is one of those. Maybe you can lend a soldering iron or other solder brands just to compare and get some more experience.

Yet another possibility is that the things you try to solder are to much oxidized. This may prevent the solder (+flux) from wetting it properly too.