Soldering newbie

I am not new to soldering. I have some soldering experience. I have built a radio kit with no soldering problems whatsoever. I have made little boards for things like transistor amplifiers for my crystal radio. I have little surface mount experience, but in a moment of extreme courage, my boss let m e rework about 50 PCBs at once when he was on vacation. That involved solde ring a little SMT cap using tiny little wire to a nearby IC pin. Most of th e boards worked, but the job looked horribly ugly.

The reason I consider myself still a newbie, is that successes are not alwa ys repeatable, and failures are not always avoidable.

I have read numerous guides on the Internet but some things really don't cl ick. I thought I could start this thread to ask questions that will probabl y be obvious to some but still not very clear to me.

The questions at hand for now are these:

1) Soldering guides always recommend you to tin the tip of your iron with f resh solder before starting on a joint. Every time I do this the solder bur ns and discolors. Is that normal or am I doing something wrong? Do I have t o be really fast before solder burns?

2) Soldering guides tell you to always heat the joint not the solder. Whene ver I do this, it seems it takes forever for solder to melt. It also seems that the pointy part of the tip (as they always show in drawings) isn't rea lly hot enough I have to find a sweet spot on the tip that is hot enough an d then touch it to the wire. Do I just have a bad iron?

3) Can I use copper wool instead of a wet sponge? I have been using it rece ntly with success. The problem is that I'm not sure if it's better than a s ponge or not. I'm not even sure of the function of the copper or the sponge . I know it's for wiping the tip clean but it's hard for me to gauge how mu ch better cleaning the tip actually provides.

4) When to use flux and when is it not important? I soldered the transistor radio kit completely without flux. But also the type of solder they provid ed with the kit seemed really good, I thought may be the solder has it all.

I know this has been answered a million times before but if someone is feel ing bored may be they can share their experience. I know I probably can spe nd hours scouring internet forums and getting all sorts of conflicting info rmation. I thought I may get some direct answers here! THANKS.

Reply to
M. Hamed
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Discolors how? If it turns brown it's not the solder -- it's the flux. If it turns gray, then the solder is oxidizing. The flux getting a bit brown isn't that bad, but either one of these things happening is an indication of your iron being too hot. You probably can't get away from this easily without using a temperature-controlled iron.

If you have tip cleaner or a damp sponge that'll work well, too. The tip needs to be tinned, but more importantly it needs to be clean.

(Don't use a temperature controlled iron unless you already own it, or have long-term access. They're instantly addictive. It'll be like the first time someone took the butter knife out of your hand and gave you a real screwdriver -- you won't want to go back).

It could be. But it could just be that the tip isn't clean, or isn't tinned enough. Dirt, oxidized solder, and burnt flux don't transmit heat well.

What you're really trying to do is to make sure that the whole joint is hot enough to melt solder -- you can do a perfectly good solder joint by dribbling solder on it, then reheating everything. But unless you're really good, you can't tell the difference between a good joint done this way and a poor joint done this way. Melting the solder onto the metal to be soldered is a 100% reliable way of making sure it's at soldering temperature.

If the tip is clean, you've done a good job. I haven't used copper wool much (mostly when someone shoved a soldering iron under my nose). All of the people that I know who solder Really Well use a sponge.

They (and I) use a _damp_ sponge -- if it's dripping, it's way too wet: it'll freeze the solder on the tip and stick the gunk on solid.

Electronic solder comes with flux built in -- the solder is actually a hollow tube filled with flux (or, sometimes, a tube with more than one hole, all filled with flux).

If you've been using anything other than flux intended for electronics then you've been using the Wrong Stuff. Flux for electronics (usually called "rosin flux") is very mild, and the stuff you're expected to solder is easy to solder to. Flux for mechanical assemblies ("acid flux") is much more harsh -- which is what you want when you need to solder to steel or other difficult materials, but it causes corrosion if it's not cleaned all the way off of your job, and it's almost impossible to clean electronics 100%.

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Reply to
Tim Wescott

radio kit with no soldering problems whatsoever. I have made little boards for things like transistor amplifiers for my crystal radio. I have little surface mount experience, but in a moment of extreme courage, my boss let me rework about 50 PCBs at once when he was on vacation. That involved soldering a little SMT cap using tiny little wire to a nearby IC pin. Most of the boards worked, but the job looked horribly ugly.

repeatable, and failures are not always avoidable.

I thought I could start this thread to ask questions that will probably be obvious to some but still not very clear to me.

solder before starting on a joint. Every time I do this the solder burns and discolors. Is that normal or am I doing something wrong? Do I have to be really fast before solder burns?

Your iron is too hot. You need one of the temperature-controlled ones. Metcal are the best.

I do this, it seems it takes forever for solder to melt. It also seems that the pointy part of the tip (as they always show in drawings) isn't really hot enough I have to find a sweet spot on the tip that is hot enough and then touch it to the wire. Do I just have a bad iron?

I poke the tip into the intersection of the board and the part, and apply solder to the 3-way intersection. That wets everything and transfers a bunch of heat fast.

with success. The problem is that I'm not sure if it's better than a sponge or not. I'm not even sure of the function of the copper or the sponge. I know it's for wiping the tip clean but it's hard for me to gauge how much better cleaning the tip actually provides.

It's to remove excess solder and burnt, crusty old flux. Sponge works.

radio kit completely without flux. But also the type of solder they provided with the kit seemed really good, I thought may be the solder has it all.

Usually the flux in rosin-core electronic solder is all you need. I rarely add additional liquid flux.

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John Larkin         Highland Technology, Inc 

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Reply to
John Larkin

radio kit with no soldering problems whatsoever. I have made little boards for things like transistor amplifiers for my crystal radio. I have little surface mount experience, but in a moment of extreme courage, my boss let me rework about 50 PCBs at once when he was on vacation. That involved soldering a little SMT cap using tiny little wire to a nearby IC pin. Most of the boards worked, but the job looked horribly ugly.

repeatable, and failures are not always avoidable.

click. I thought I could start this thread to ask questions that will probably be obvious to some but still not very clear to me.

fresh solder before starting on a joint. Every time I do this the solder burns and discolors. Is that normal or am I doing something wrong? Do I have to be really fast before solder burns?

Oy! You'll give the poor guy a heart attack.

Once the OP has started breathing again, he might want to look for something like It's not a knock-off brand and is reasonably inexpensive (as these things go). Some (of many more) alternates are over at where they have house-branded stations. Haven't tried these but I've purchased other stuff from them in the past w/o complaints.

Reply to
Rich Webb

"M. Hamed"

1) Soldering guides always recommend you to tin the tip of your iron with fresh solder before starting on a joint. Every time I do this the solder burns and discolors.

** The iron is too hot, get an adjustable or temp controlled one.

It is possible to use a light dimmer with a cheap iron to reduce the temp.

2) Soldering guides tell you to always heat the joint not the solder. Whenever I do this, it seems it takes forever for solder to melt.

** When you touch the tip against a joint, immediately apply a little solder to tip so the hot solder carries the heat around.

It also seems that the pointy part of the tip (as they always show in drawings) isn't really hot enough I have to find a sweet spot on the tip that is hot enough and then touch it to the wire. Do I just have a bad iron?

3) Can I use copper wool instead of a wet sponge?

** Brass wool is best.

4) When to use flux and when is it not important? I soldered the transistor radio kit completely without flux. But also the type of solder they provided with the kit seemed really good, I thought may be the solder has it all.

** Use only flux cored, 60:40 tin lead solder for electronics.

Avoid the lead free kind.

... Phil

Reply to
Phil Allison

If the iron wasn't tinned right at the beginning, then the tip gains some coating that causes the solder to just roll off.

I have a vague memory of this happening once, but I can't remember what I did. I do know that when you have properly tinned the tip from the beginning, some residue can build up, and you need to work at clearing that up so the solder doesn't ball and roll off when heated, but spreads out over the tip.

I also have a vague memory of burning solder on one iron, yet it seems more related to an untinned tip. Because it's not like I've bought endless packs of solder over the years, and the same solder works fine on my soldering gun, which is much hotter than the irons I've had in forty years. I think maybe I ended up with some bad solder, or solder rated at a lower temperature. But it's been decades.

The guides all say that, but most people do melt some solder on the tip as it is held against the joint. The melted solder helps the heat to flow. Once there is a bit of solder on the joint, the heat flows more easily.

No. Except really cheap irons (the tips will last a very short time), soldering iron tips have been plated for decades. If you use something metallic to clean it, you may clear off the plating. The plating is a great thing, it protects the tip. Without it, the tip will decay after a relatively short time, while all the plated tips I've had last forever.

You don't want a lot of solder on a tip, at least when you are soldering, yet keeping some solder on the tip protects it. So you pull your iron out of the stand, briefly wipe it on the sponge (paper towels work too, I don't even bother dampening them) before you solder, and then before you put the iron back in the stand (at least if it will be sitting there for a while), add a bit more solder.

So it's primarily to get the excess solder off, something you don't need steel or copper wool for.

There are times when there's sort of a carbon buildup, I guess solder left on the tip too long without being wiped off, and that takes some work to clear off, but no actual filing or need for steel wool. But the build up happens because the excess solder isn't regularly wiped off.

That said, again if you don't tin the tip properly at the start, there will be later problems.

The solder has flux built in. Melting a bit of solder on the tip of the iron helps to spread the flux onto the joint you are trying to solder. Same thing happens with old solder, the flux has long gone, you try really hard to heat up the joint but no success. Melt a bit of solder against the iron on the joint, and the new solder provides flux for the heat to flow, so the old solder melts like it should.

Michael

Reply to
Michael Black

a radio kit with no soldering problems whatsoever. I have made little boar ds for things like transistor amplifiers for my crystal radio. I have littl e surface mount experience, but in a moment of extreme courage, my boss let me rework about 50 PCBs at once when he was on vacation. That involved sol dering a little SMT cap using tiny little wire to a nearby IC pin. Most of the boards worked, but the job looked horribly ugly.

ways repeatable, and failures are not always avoidable.

click. I thought I could start this thread to ask questions that will proba bly be obvious to some but still not very clear to me.

fresh solder before starting on a joint. Every time I do this the solder b urns and discolors. Is that normal or am I doing something wrong? Do I have to be really fast before solder burns?

never I do this, it seems it takes forever for solder to melt. It also seem s that the pointy part of the tip (as they always show in drawings) isn't r eally hot enough I have to find a sweet spot on the tip that is hot enough and then touch it to the wire. Do I just have a bad iron?

cently with success. The problem is that I'm not sure if it's better than a sponge or not. I'm not even sure of the function of the copper or the spon ge. I know it's for wiping the tip clean but it's hard for me to gauge how much better cleaning the tip actually provides.

or radio kit completely without flux. But also the type of solder they prov ided with the kit seemed really good, I thought may be the solder has it al l.

eling bored may be they can share their experience. I know I probably can s pend hours scouring internet forums and getting all sorts of conflicting in formation. I thought I may get some direct answers here! THANKS.

Another trick is to coat both surfaces with solder before joining them together and clean the surface of the leads. So, if you want to solder two resistor leads together, use an exacto knife to scrape the resistor leads clean and then apply a thin coat of solder to each lead. Then put the resistor leads together and solder the joint. You may not need any solder on the iron, just heat the leads and they will melt together..

-BIll

Reply to
Bill Bowden

"Bill Bowden"

Another trick is to coat both surfaces with solder before joining them together and clean the surface of the leads. So, if you want to solder two resistor leads together, use an exacto knife to scrape the resistor leads clean ...

** You should never have to do that.

Only very old and badly corroded leads require scraping.

.... Phil

Reply to
Phil Allison

"M. Hamed"

I know this has been answered a million times before but if someone is feeling bored may be they can share their experience. I know I probably can spend hours scouring internet forums and getting all sorts of conflicting information. I thought I may get some direct answers here!

** There are two common reasons why beginners have problems soldering:

  1. They are using a shit awful soldering iron.

  2. They are using lead free or flux free solder.

Hamed, like most, has not revealed what HE is using.

.... Phil

Reply to
Phil Allison

No kidding. Metcals are insanely overpriced, even if they now have a station in the mid $200 range. Jes get a Hakko FX888. You can get 'em fer < $85 and they have a great range of tips, even down into SMT sizes.

nb

Reply to
notbob

radio kit with no soldering problems whatsoever. I have made little boards for things like transistor amplifiers for my crystal radio. I have little surface mount experience, but in a moment of extreme courage, my boss let me rework about 50 PCBs at once when he was on vacation. That involved soldering a little SMT cap using tiny little wire to a nearby IC pin. Most of the boards worked, but the job looked horribly ugly.

repeatable, and failures are not always avoidable.

click. I thought I could start this thread to ask questions that will probably be obvious to some but still not very clear to me.

fresh solder before starting on a joint. Every time I do this the solder burns and discolors. Is that normal or am I doing something wrong? Do I have to be really fast before solder burns?

Whenever I do this, it seems it takes forever for solder to melt. It also seems that the pointy part of the tip (as they always show in drawings) isn't really hot enough I have to find a sweet spot on the tip that is hot enough and then touch it to the wire. Do I just have a bad iron?

recently with success. The problem is that I'm not sure if it's better than a sponge or not. I'm not even sure of the function of the copper or the sponge. I know it's for wiping the tip clean but it's hard for me to gauge how much better cleaning the tip actually provides.

radio kit completely without flux. But also the type of solder they provided with the kit seemed really good, I thought may be the solder has it all.

feeling bored may be they can share their experience. I know I probably can spend hours scouring internet forums and getting all sorts of conflicting information. I thought I may get some direct answers here! THANKS.

If the leads are oxidized like that, switching to RA-flux solder will improve your life. I have a bunch of old parts that I still use, and RA is the bomb.

Cheers

Phil Hobbs

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Reply to
Phil Hobbs

radio kit with no soldering problems whatsoever. I have made little boards for things like transistor amplifiers for my crystal radio. I have little surface mount experience, but in a moment of extreme courage, my boss let me rework about 50 PCBs at once when he was on vacation. That involved soldering a little SMT cap using tiny little wire to a nearby IC pin. Most of the boards worked, but the job looked horribly ugly.

always repeatable, and failures are not always avoidable.

click. I thought I could start this thread to ask questions that will probably be obvious to some but still not very clear to me.

fresh solder before starting on a joint. Every time I do this the solder burns and discolors. Is that normal or am I doing something wrong? Do I have to be really fast before solder burns?

Whenever I do this, it seems it takes forever for solder to melt. It also seems that the pointy part of the tip (as they always show in drawings) isn't really hot enough I have to find a sweet spot on the tip that is hot enough and then touch it to the wire. Do I just have a bad iron?

recently with success. The problem is that I'm not sure if it's better than a sponge or not. I'm not even sure of the function of the copper or the sponge. I know it's for wiping the tip clean but it's hard for me to gauge how much better cleaning the tip actually provides.

radio kit completely without flux. But also the type of solder they provided with the kit seemed really good, I thought may be the solder has it all.

feeling bored may be they can share their experience. I know I probably can spend hours scouring internet forums and getting all sorts of conflicting information. I thought I may get some direct answers here! THANKS.

Is there a downside to RA? Is it corrosive or conductive or anything? We use RMA, not sure why. RMA does not seem to be conductive, at the 1e14 ohm level, even at high humidity.

--
John Larkin                  Highland Technology Inc 
www.highlandtechnology.com   jlarkin at highlandtechnology dot com    
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Reply to
John Larkin

radio kit with no soldering problems whatsoever. I have made little boards for things like transistor amplifiers for my crystal radio. I have little surface mount experience, but in a moment of extreme courage, my boss let me rework about 50 PCBs at once when he was on vacation. That involved soldering a little SMT cap using tiny little wire to a nearby IC pin. Most of the boards worked, but the job looked horribly ugly.

always repeatable, and failures are not always avoidable.

click. I thought I could start this thread to ask questions that will probably be obvious to some but still not very clear to me.

fresh solder before starting on a joint. Every time I do this the solder burns and discolors. Is that normal or am I doing something wrong? Do I have to be really fast before solder burns?

Whenever I do this, it seems it takes forever for solder to melt. It also seems that the pointy part of the tip (as they always show in drawings) isn't really hot enough I have to find a sweet spot on the tip that is hot enough and then touch it to the wire. Do I just have a bad iron?

recently with success. The problem is that I'm not sure if it's better than a sponge or not. I'm not even sure of the function of the copper or the sponge. I know it's for wiping the tip clean but it's hard for me to gauge how much better cleaning the tip actually provides.

radio kit completely without flux. But also the type of solder they provided with the kit seemed really good, I thought may be the solder has it all.

feeling bored may be they can share their experience. I know I probably can spend hours scouring internet forums and getting all sorts of conflicting information. I thought I may get some direct answers here! THANKS.

I think it's more acidic than RMA, so it may be more corrosive and/or leakier, I'm not entirely sure. It really makes dead bugging easier though.

Speaking of prototyping, those Bellin Systems breakout boards have a crappy solder mask--it doesn't go between pins on 0.025" or 0.5 mm pitch parts. I may switch to Schmartboards, even though they're much more expensive

Cheers

Phil Hobbs

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Dr Philip C D Hobbs 
Principal Consultant 
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Reply to
Phil Hobbs

a radio kit with no soldering problems whatsoever. I have made little boards for things like transistor amplifiers for my crystal radio. I have little surface mount experience, but in a moment of extreme courage, my boss let me rework about 50 PCBs at once when he was on vacation. That involved soldering a little SMT cap using tiny little wire to a nearby IC pin. Most of the boards worked, but the job looked horribly ugly.

always repeatable, and failures are not always avoidable.

click. I thought I could start this thread to ask questions that will probably be obvious to some but still not very clear to me.

fresh solder before starting on a joint. Every time I do this the solder burns and discolors. Is that normal or am I doing something wrong? Do I have to be really fast before solder burns?

Whenever I do this, it seems it takes forever for solder to melt. It also seems that the pointy part of the tip (as they always show in drawings) isn't really hot enough I have to find a sweet spot on the tip that is hot enough and then touch it to the wire. Do I just have a bad iron?

recently with success. The problem is that I'm not sure if it's better than a sponge or not. I'm not even sure of the function of the copper or the sponge. I know it's for wiping the tip clean but it's hard for me to gauge how much better cleaning the tip actually provides.

transistor radio kit completely without flux. But also the type of solder they provided with the kit seemed really good, I thought may be the solder has it all.

feeling bored may be they can share their experience. I know I probably can spend hours scouring internet forums and getting all sorts of conflicting information. I thought I may get some direct answers here! THANKS.

I love the Bellins... just bought a few more sheets. Each adapter winds up costing around 30 cents, about 1/10 of some others. I hadn't noticed any difficulty soldering, but I mostly use SOT23 and SO8 sorts of packages, not any big fine-pitch parts. Once you get to stuff like uPs and ADCs and things, it makes sense to lay out a real PC board.

We accumulate a list of cool circuits, adapters, crazy ideas, whatever, and when we need to prototype a nontrivial circuit, we toss those extras around it and lay out a board, usually 4-layer, and buy 10 of them. We lay things out so you can shear or saw things apart. Here's the latest one:

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We included the RJ45 to SMA breakout because we couldn't find one anywhere!

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John Larkin                  Highland Technology Inc 
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Reply to
John Larkin

Yes, it is brownish with some blue. You're right it's most likely the flux. I do have a temperature controlled station. I looked last night at the temp erature setting and it was about 750-800.

So do I need to clean every time before applying solder?

Yes, I am realiz> Usually the flux in rosin-core electronic solder is all you need. I

I see the experts at work use flux all the time. My guess is that it's need ed for 1-Lead free solder> ** When you touch the tip against a joint, immediately apply a little sol

der

This is more or less what I used to do and solder seemed to melt easier thi s way. However I read > If the iron wasn't tinned right at the beginning, then the tip gains some

But even with tinning the burnt flux still coats the tip. I will retry redu cing the temp as everyone is suggesting.

s

Oh, Thank you! That was my experience too. I always felt guilty about it th ough :)

t

a

So you're say> ** There are two common reasons why beginners have problems soldering:

Phil, I do not use lead free, except if I have to do some solder> Once the OP has started breathing again, he might want to look for

Rich, I have this:

formatting link

--------------------------- Sorry for the long post.

Reply to
M. Hamed

temperature setting and it was about 750-800.

cleaning sponges but I didn't know they had extra chemicals on them. I had a hard time finding one that doesn't have stuff added. The one that came with the soldering station is in a bad shape.

I've become fond of using brass turnings to wipe the tip but another possibility is to use pieces of an old cotton t-shirt. No water, just wipe quickly. Yes, it will scorch some but it cleans the tip fairly well and doesn't cool it down appreciably. (Note: cotton NOT polyester or a blend.)

for 1-Lead free soldering, 2-Surface mount components with very small pitch?

Flux reacts with and removes the surface oxides at the joint, allowing the solder to wet the metals and make a good connection. It's like trying to glue two sheets of waxed paper together with a water-based glue ('white glue' like Elmer's). No wetting, no sticking. With the flux, it's as if the wax were removed and you're gluing two sheets of plain paper.

When hand-soldering a fine pitch SMT part, pre-fluxing the pads on the board and the leads on the device encourages the solder to flow into the space between each lead and its corresponding pad, rather than bunching up into solder bridges.

way. However I read in many places where they tell you this is a big NO NO.

It is A Bad Thing to load the tip with solder and then just wipe it on the joint or to feed the solder only onto the iron's tip. That may look okay (from a distance) but there's little or no wetting and so the joint is very weak.

However, having just a little dab of solder on the tip can help in heat transfer. The goal is to heat the lead and the pad together and then feed the solder into the joint.

the temp as everyone is suggesting.

700 F is a typical tip temperature to use with 60-40.

For the gunk that's already on there, Radio Shack (among others, but you probably don't pass those others on the drive home) sells a little tin of "tip cleaner." Wipe the tip clean after using the cleaner and then "wash" it with a couple applications of your regular solder.

Some of the irons in the lab here aren't very well taken care of (the desoldering irons seem to get it the worst) but this stuff goes a long way to getting them back in shape.

Looks good. Do turn the temperature down a bit, though.

Reply to
Rich Webb

"M. Hamed"

This is more or less what I used to do and solder seemed to melt easier this way. However I read in many places where they tell you this is a big NO NO.

** I have just seen a site where the writer gives this and other WRONG advice too.

It is a common mistake to apply solder to the tip and then carry it to the joint - but that is NOT my advice.

The idea is to AID the tip in heating the joint FAST by *re-tinning* it as you go.

So, after applying the tip, add a dab of solder - then as the solder flows around add a more to the joint itself.

Good soldering is done very quickly, blink and you will miss it.

A slow motion, close up vid would be good.

... Phil

Reply to
Phil Allison

"Phil Allison"

** This one will do nicely....

formatting link

... Phil

Reply to
Phil Allison

"Phil Allison"

** You may have to copy and paste the link into YouTube.

.... Phil

Reply to
Phil Allison

So is a small solder pot where you can clean & re-tin the leads at the same time. I used one for years to clean the pins on used ICs, and old stock components. It's easier to deflux loose components than ones in an assembly.

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Reply to
Michael A. Terrell

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