Recap of Soldering 101

[R.G.]

I don't want to interfere with a well-developed and amusing discussion of spelling, phonetics and linguistics. Please continue with that. However, there is a really important point that is nearly universally missed in discussions of soldering. That is, all soldering, like all politics, is local. And it takes time.

If you touch one end of a wire with a soldering iron while you are holding the other end of the wire, it will take some time before you let go of the wire because it's burning your fingers. Try it, but use a wire a couple of inches long. The heat has to warm more mass as it travels along the wire, and the wire has a certain resistance to heat travel, so it takes some time.

When you make a soldered joint, you have to have the iron clean, tinned, and fluxed. You have to have the base materials in the joint clean and fluxed. You have to have the iron hot enough to melt the solder. And you have to allow enough time for the joint to heat so that 100% of the surfaces you want to accept solder are hot enough to actually be wetted.

But it works the other way too. If you want to keep the temperature rise from soldering right at the joint, you can heat the joint so fast that it solder-wets before the heat has time to travel along the wires to something else. This is how you can avoid heat damage to germanium or other delicate parts. Prepare the base materials in the joint, get them clean and fluxed, then use a HOT iron, heat till the solder flows out, then GET THE IRON OUT OF THERE.

It takes some practice, but you can do it. I can solder two 1" long resistor leads while holding the other ends in my bare fingers without burning my fingers - well, OK, not burning them too badly. But I've had lots of practice.

Soldering takes time - less or more, and you get to control the timing as well as the other items.

[Rob Strand]

And you have to allow enough time for the joint to heat so that 100% of the surfaces you want to accept solder are hot enough to actually be wetted.

And there's an enormous difference in the heat transfer of a dry iron tip on a dry component than a tinned iron tip and a tinned iron tip.   Getting solder in there is the best way to prevent overheating stuff since the heat gets across asap.

Also,
https://youtu.be/vIT4ra6Mo0s?list=PL926EC0F1F93C1837&t=730

[PRR]

..... soldering sensitive and expensive germanium transistors or diodes, I might use a clip to protect it, but otherwise probably wouldn't bother.
The other expensive stuff would be chips, and for that I'd use sockets, which would be a valid solution for the germaniums too.

It's not the expense.

Silicon is not ruined by a visit to soldering temperature. Germanium is.

[CodeMonk]

why can't people pronounce Solder and Soldering properly? Its NOT sodder or soddering!

How do you pronounce these words: talk, walk, folk, would, could, should, half, colonel, etc.? Coming from the nation that created the least sensible spelling system for a language in all of history, maybe lay off the judgement. /rant

another +1 for ditching the wet sponge and using "steel wool" type stuff instead.

Tin all wires before attempting to solder them.

Through-hole components can have very oxidized leads. If I notice a dull lead, I grab it with a knurled needlenose pliers and (gently) scrape it down until it's shiny. Takes only a few seconds and prevents cold joints.

I find that using one of those pink pencil erasers works better.
I've also used them on all sorts of components and parts to remove oxidation.

Any wires that you need for whatever you are working on that need to be tinned, tin all of them at the same time.
I made this to help in that:


I just used a couple of roofing nails to hold the spring.

[11-90-an]

why can't people pronounce Solder and Soldering properly? Its NOT sodder or soddering!

How do you pronounce these words: talk, walk, folk, would, could, should, half, colonel, etc.? Coming from the nation that created the least sensible spelling system for a language in all of history, maybe lay off the judgement. /rant

another +1 for ditching the wet sponge and using "steel wool" type stuff instead.

Tin all wires before attempting to solder them.

Through-hole components can have very oxidized leads. If I notice a dull lead, I grab it with a knurled needlenose pliers and (gently) scrape it down until it's shiny. Takes only a few seconds and prevents cold joints.

I find that using one of those pink pencil erasers works better.
I've also used them on all sorts of components and parts to remove oxidation.

Any wires that you need for whatever you are working on that need to be tinned, tin all of them at the same time.
I made this to help in that:


I just used a couple of roofing nails to hold the spring.

Hmm never tried pencil erasers...
That spring should be put into better use with an analog spring reverb (yeah i know it isn't built for it, but why not try...?)

[marcelomd]

I like to use a bit of iron wool, or light sandpaper to remove the oxidation from leads.

I also use blue tack to hold things down. Works wonders.

In the past I tried too hard to make the joints mechanically secure by looping wires or leads around solder lugs. It was impossible to undo the joints later even if I wanted to.

[Phend]

So my 1/4 watt el-cheap-o plug-it-in soldering iron should be replaced with one with a temperature adjustment dial ? What is a good iron to buy ? The el-cheap-o worked for soldering leads to 14 gage copper wire !!

Thanks all for contributing to this Recap of Soldering 101, it has given great tips and entertained.

[Rob Strand]

Technically those scourer things to clear the tip should be made of brass so it doesn't wear away the iron coating on the tip.   How much difference it makes in practice I don't know off the top of my head.

[11-90-an]

Basically the summary of this whole thread:

- Clean your soldering iron tip with either a wet sponge or towel, or steel or brass wool thingy.... What works for you will work
- Tin your wires and component leads for easy soldering... What works for others works for you
- Clean your PCBs with slight abrasives and whatever to remove oxidation to make soldering easy... What works is what you have
- Have a good soldering iron... What you have will have to suffice until you can get another one (unless you can't)
- ITS PRONOUNCED AS "SOULLLLLLDER"

 

[Mark Hammer]

I like to use a bit of iron wool, or light sandpaper to remove the oxidation from leads.

The vast majority of us are not operating pedal-making businesses.  This means that we might buy a parts kit that we eventually get around to building, or might purchase an order of parts from a supplier, stick them in the appropriate parts drawers and then eventually get around to using them.  The point is that the time between when we acquire components and the time when we use them, leaves plenty of time for the leads to tarnish.  And tarnish impedes solder flow.  That is true of leads on passive components, pins on semiconductors, and traces on PCBs.  Myself, I keep an X-acto blade handy to scrape the tarnish off, when required.  Steel wool and sandpaper can work too, but a pointy blade lets you get into a wider variety of spaces more easily.

When I etch my boards, immediately after buffing down the etched copper side, I will apply a thin coating of liquid flux, and then tin the entire board with solder and my iron.  The flux allows the teensiest bit of solder to spread over a considerable area.  Once tinned, I go over the board with a tissue and some methyl hydrate to remove all the flux.  Although solder itself CAN eventually tarnish - it's not exactly gold-plating - bare copper tarnishes MUCH faster, so tinning tends to preserve the board in good shape for me, and components form nice joints easily, even many months later.  A small bottle of liquid flux can last you years.  Sometimes, dabbing a little bit of liquid flux on switch solder lugs with a cotton-tipped applicator can really speed up solder flow and avoid heat damage.  Pre-tinning component and wire leads also helps.

I used to use the sponge that came with the soldering iron.  Tips would last me maybe 6-8 months before eroding and needing replacement.  I switched to the "brass wool thingy" (copper, actually, and readily available at 3 for a dollar in the dollar stores) and have had the same tip for what is probably 6-8 years now, without any erosion of the tip whatsoever.

[Phend]

- ITS PRONOUNCED AS "SOULLLLLLDER"

I once knew an ODDER that knew how to SODDER with an iron that was even HODDER.
sol·der ... /ˈsädər/
That is the way it is said in the UP of Michigan, yes Yoopers are weird. 
But when in Rome say it the way the Romans do !

[duck_arse]

the romans say sole-dURR.

[CodeMonk]

I like to use a bit of iron wool, or light sandpaper to remove the oxidation from leads.

The vast majority of us are not operating pedal-making businesses.  This means that we might buy a parts kit that we eventually get around to building, or might purchase an order of parts from a supplier, stick them in the appropriate parts drawers and then eventually get around to using them.  The point is that the time between when we acquire components and the time when we use them, leaves plenty of time for the leads to tarnish.  And tarnish impedes solder flow.  That is true of leads on passive components, pins on semiconductors, and traces on PCBs.  Myself, I keep an X-acto blade handy to scrape the tarnish off, when required.  Steel wool and sandpaper can work too, but a pointy blade lets you get into a wider variety of spaces more easily.

When I etch my boards, immediately after buffing down the etched copper side, I will apply a thin coating of liquid flux, and then tin the entire board with solder and my iron.  The flux allows the teensiest bit of solder to spread over a considerable area.  Once tinned, I go over the board with a tissue and some methyl hydrate to remove all the flux.  Although solder itself CAN eventually tarnish - it's not exactly gold-plating - bare copper tarnishes MUCH faster, so tinning tends to preserve the board in good shape for me, and components form nice joints easily, even many months later.  A small bottle of liquid flux can last you years.  Sometimes, dabbing a little bit of liquid flux on switch solder lugs with a cotton-tipped applicator can really speed up solder flow and avoid heat damage.  Pre-tinning component and wire leads also helps.

I used to use the sponge that came with the soldering iron.  Tips would last me maybe 6-8 months before eroding and needing replacement.  I switched to the "brass wool thingy" (copper, actually, and readily available at 3 for a dollar in the dollar stores) and have had the same tip for what is probably 6-8 years now, without any erosion of the tip whatsoever.

After I etch my boards, I hit them with 400 - 500 grit or 0000 steel wool.
Then I use MG Chemicals Liquid Tin.
Never had an problem with corrosion. But I also live in Nevada, which has very low humidity.

One thing I have always done with my tips to keep them healthy is to use a wet sponge really good and get all the solder off of it, then apply fresh solder to the tip. Then turn it off.

At one place I worked at in the 80s (JPL), we got a shitload of SMD ICs where all the leads had bad corrosion. And I'm talking several thousand ICs.
Couldn't really return them for new ones since they weren't off the shelf parts, and couldn't spare the time for another run, and for NASA, cost isn't as big a factor as time.
We set up a solder pot, some really acidic flux, and a tub of 1 1 1-trichloroethylene (tub = code word for 9x12 glass baking dish). We had special made clamping tweezers that not only held the parts, but also clamped down on the leads next to the component body to act as a heat sink.

[mozz]

Been building Heathkits since back in the 70's with my paper route money. (sunday paper was 35c) Military certified since 1980 (was never in the military). Still soldering most daily at work.

Quality adjustable iron, Weller, Hakko, Pace, it makes a difference. 63/37 usually. I have a few sizes of solder on hand depending what i am working with. Biggest maybe .031. Used to do 0603 0805 with a pointy iron tip but that was 15 years back. Hardly ever use flux or heatsinks.

Practice.

Get in get out.

Do not solder in bare feet. (no need to ask why)

[CodeMonk]

- ITS PRONOUNCED AS "SOULLLLLLDER"

I once knew an ODDER that knew how to SODDER with an iron that was even HODDER.
sol·der ... /ˈsädər/
That is the way it is said in the UP of Michigan, yes Yoopers are weird. 
But when in Rome say it the way the Romans do !

I've spent 30+ years working with electronics.
Much of it in Southern California working in manufacturing, primarily military and aerospace.
And I am currently working at Tesla.
In all these years, I NEVER heard it pronounced differently than that.
And I still pronounce it that way.

Been building Heathkits since back in the 70's with my paper route money. (sunday paper was 35c) Military certified since 1980 (was never in the military). Still soldering most daily at work.

Quality adjustable iron, Weller, Hakko, Pace, it makes a difference. 63/37 usually. I have a few sizes of solder on hand depending what i am working with. Biggest maybe .031. Used to do 0603 0805 with a pointy iron tip but that was 15 years back. Hardly ever use flux or heatsinks.

Practice.

Get in get out.

Do not solder in bare feet. (no need to ask why)

And wear long pants. Shorts are a big no-no. Try it in shorts to find out why. And NOT polyester. Jeans are preferable.

[PRR]

Even good dictionaries note that we do not use the "L" in North America.

Back in a NJ Radio Shack a guy from Georgia came in looking for 'solllder'. The clerk and I both took time to hear it right. I do not know if he learned it from a book, or if British "soLder" persisted in parts of the South. (Yes radio/TV unified US speech, but nobody talks about solder on the radio.) It really sounded odd to our "sodder" ears. 

[Phend]

According to the Oxford dictionary (Oxford is in Mississippi):
Jethro Bodine went to school there.

/ˈsɑːdər/ [uncountable] ​a mixture of metals that is heated and melted and then used to join metals, wires, etc. together.

Spoken like this:

https://www.google.com/search?client=avast&q=soldering

But as Bob Dylan says:
(1965) "The Times They Are a-Changin"

K IMHO WT* OMG LOL I remember texting on a type writer (what's a type writer?) Now I use a mouse pad (what's a mouse pad?) guess I am getting old, the times they are a changin.

[Phend]

Jethro:

[ElectricDruid]

So my 1/4 watt el-cheap-o plug-it-in soldering iron should be replaced with one with a temperature adjustment dial ? What is a good iron to buy ? The el-cheap-o worked for soldering leads to 14 gage copper wire !!

It doesn't have to be temperature controlled. I used one of these for about thirty years:

https://www.amazon.co.uk/Antex-S58J470-XS25-Silicone-Soldering/dp/B003ITY13W

It's a basic but excellent tool, and the fact they're still making it thirty years later (it used to be called "X25" not "XS25", but that's all that's altered) is some kind of testament to its quality.

In the end, mine became like one of those "grandfather's axe" paradoxes. Over the years, I'd replaced the tip several times, the element once, and the handle! Was it still the same soldering iron?

[Phend]

Thanks for the tip, lol, yours has a much smaller tip, I shall look on Amazon.
Actually the new one I have is made in USA by Lenk model L25, which, except for the yellow handle is also the same as my 30 yr old one. Same company same model. If something works don't fix it, wish they did the same for cars, but then the engineers ect..would not get paid.