Introduction: Soldering Is NOT Rocket Science!

Picture of Soldering Is NOT Rocket Science!

I've seen so many articles on electronic soldering that are either overly verbose and hard to read, too complex for a beginner, insist on expensive tools, or are just plain wrong, that I decided to clear the air a bit by going back to the basics. When I first started soldering, many years ago, "How To Solder" was printed on the back of the soldering iron package with room to spare. After that, it was just practice. This is not hard stuff, and it's not complicated, either. It's just a matter of a handful of basic principles:

  1. Choose the right soldering tool.
  2. Use the right solder with rosin flux.
  3. Cleanliness is essential, both for the iron and the work.
  4. Contact both parts of the work with the iron.
  5. Use the work to melt the solder, not the iron.

I learned many of these techniques on a production line in the 80s, so I've done a lot of hand soldering.

The Soldering Comic Book attached is a good quick reference.

Step 1: Choose the Right Soldering Utensil

Picture of Choose the Right Soldering Utensil

To solder electronics, you need a soldering iron, not a soldering gun. Soldering guns are designed for large, bulky projects like copper pipe or gutters. They are too imprecise and too powerful for delicate soldering. In addition, they work by putting current directly through the tip, and that current could potentially damage sensitive semiconductors.

Your first soldering iron should be in the 25-40 Watt range. It does not need to be one of those fancy ones with temperature control. I've been using non-temperature-controlled irons for decades, and they do just fine for all but the most demanding jobs. The $10 one from Radio Hovel or WalMart will do just fine when you're starting out. You'll know when your work demands something better.

If you'll be soldering a lot of CMOS ICs (integrated circuits), they are static sensitive, and a grounded iron with a 3-prong plug will help, or just solder in IC sockets and put in the ICs when all soldering is done. This is safer, anyway, until your skills are better.

Step 2: Use Solder and Flux Designed for Electronics

Picture of Use Solder and Flux Designed for Electronics

You want onlyRosin Core Solder for soldering electronics. The rosin acts as flux (A substance that helps prevent oxidation and promotes bonding). Flux is essential, but the wrong kind of flux will destroy your project. Acid core solder should be paired with that soldering gun, and used only for plumbing and home repairs. The kind of solder you can buy at Radio Shack is the right kind.

Choose a diameter of solder based on the size of your soldering job. Diameters are given in Inches. For general electronic soldering, .025" or .030" is OK. For fine work like Surface Mount components, use .015 or even .010. I've been using .015 for nearly everything, but for a big connection like an AC plug, you might have to use a foot of the stuff.

Note: Lead-free solder is environmentally correct, but a lot harder to work with and requires higher temperatures. I don't recommend it. The best kind is 63% Tin/37% Lead, although 60/40 works fine also.

Step 3: Safety Concerns

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I am assuming that you're grown-up enough to realize that soldering irons get Hot! Around 500-750 degrees F hot. (260-400 C for our friends across the Pond.) If you don't understand this, blow out a few more Birthday candles first.

Anyway, protect yourself from possible hot splatters with the appropriate gear. Safety glasses are a good idea. I'm not responsible if you hurt yourself, or burn your house down. And by the way, picking up a hot soldering iron by the wrong end is definitely not recommended. (Ask me how I know.)

You also don't want to breathe any more of the smoke and fumes than you have to. A small fan to keep the smoke out of your face will be sufficient for hobby work-You're not doing it 40 hours a week! Don't point the fan directly at your iron stand, though. It might blow hard enough to cool your iron off, and you'll be frustrated.

Step 4: Cleanliness Is Essential, Part 1

Picture of Cleanliness Is Essential, Part 1

Soldering is a process somewhat like gluing, in that the solder has to form a tight bond between the parts. Just as clean parts glue better, they also solder better. Any mud, blood, beer, grease, oil, or especially oxidation will make the joint difficult or impossible to solder well.

How do you know it's clean enough? Clean it till it's shiny. Only bare metal will solder. Tin or Gold-plated circuit boards don't need to be cleaned unless you've been a slob and gotten crud on them, but bare Copper boards can always stand a quick buffing with fine steel wool. Anything else that looks old and gray needs some cleaning before you start to solder.

"Solder Aid" sets often include a small wire brush that's very helpful. Fiberglass "Scratch Brushes," used by jewelers, are even better.

Step 5: Cleanliness Is Essential, Part 2

Picture of Cleanliness Is Essential, Part 2

Your workpiece isn't the only thing that needs to be clean. So does your soldering iron. A dirty iron won't transfer it's heat to the work very well. That's why most iron stands include a sponge. Always make sure the sponge is wet (water only) before touching it with the iron.

You clean a soldering iron by wiping it on the sponge, then tinning it. This must be done very frequently because the solder on the tip oxidizes rapidly in the heat. "Tinning" is simply the process of coating something with solder. Your tip should look silver and shiny.

My routine is, every time I pick up the iron, I give it a quick wipe on the sponge, then tin. Now I've got a clean shiny tip for maximum efficiency. The extra little blob of solder on the tip conforms to the work, increasing heat transfer.

Important Note: Never clean your tip with steel wool or sandpaper, no matter the temptation. You'll remove the plating on the tip and it will wear out very fast. The solder will literally dissolve the tip!

Step 6: Don't Just Stand There, Solder Something!

Picture of Don't Just Stand There, Solder Something!

Preliminaries out of the way, let's start soldering. The most important thing to understand about the soldering process is this: The purpose of the iron is to get the workpiece hot enough to melt the solder! Melting the solder on the iron and "dribbling" it on the work won't do at all. It just won't stick.

The proper technique is to apply the soldering iron to one side of the work, making sure it's contacting both parts to be joined. Both parts must be at soldering temperature. Then, apply the solder to the other side of the workpiece, not to the iron tip. It takes less time to do than it does to read this. After only a little practice, you can solder a PCB (Printed Circuit Board) connection in 3 to 5 seconds.

Most semiconductors are heat sensitive. Learn to solder quickly. (Another reason to use IC sockets.)

If soldering wires to wires, or wires to switches or other components, get a mechanically sound connection first. Twist wires together or wrap the wire around a terminal. If using multi-strand wire, it helps a lot to twist the end of the wire and apply a bit of solder to the wire first. Then it's easy to put a small "U" bend in the wire with your pliers and crimp that onto your terminal. Splice tiny wires, (for instance, adding long wires to an LED), by putting a "U" bend in each wire, then hooking them together and squeezing the connection down. Now they'll stay put while you solder.

Step 7: Problems and Rework

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How does your solder joint look? If it's smooth and shiny, and you can't see any gap between either part and the solder, it's probably good. A good PCB joint should be shaped something like a Hershey's Kiss.

If the hole in the board isn't covered, or the joint looks dull and granular instead of smooth, reheat and add a little more solder.

If your PCB joint looks like a beach ball, you either didn't heat the pad and the wire, or you used too much solder. Try cautiously reheating and adding a tiny bit more solder. (You add more solder in this case for the flux.) If the solder is stuck to both the wire and pad, leave it alone and use less solder next time.

Solder Wick is available from the places you buy solder, and is great for soaking up excess solder if you've used too much.

If your project is a PCB, inspect it carefully, using a magnifier if necessary, for solder "Bridges." These are most likely between IC pins. It's helpful to have a diagram of what the board is supposed to look like. If you find any bridges, reheat and scrape off the excess solder with a small tool or the iron tip itself, or use solder wick and then resolder.

Step 8: Going Further

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This information covers simple hobby soldering.

Surface Mount Devices (SMDs) can be hand soldered, also, and once you know the basics of soldering, it's not too hard. You just need a finer tip iron and a steady hand (and maybe a magnifier). The best way to solder surface mount stuff is to tin the PCB pads first with a film of solder. Then with the part in tweezers in one hand and the iron in the other, re-melt the solder on one pad and place the part into the melted solder. Hold it there till the solder solidifies. Now, go back to the other pad(s) and add a little solder to each one until all are done. Go back to the pad you started with and reheat it a bit to make sure it's good.

Other methods include the use of solder paste, but that's a subject for another day. Now get out there and solder something! Practice does make perfect.


Yonatan24 (author)2016-03-29

Hi, I've added your project to the "Beginners Guide to Soldering" Collection

This is the link If you are interested:

gizmologist (author)Yonatan242016-03-30

Thank you! I'm honored.

kudzu63 (author)2015-07-24

I have a question for someone that actually knows. I've got a battery charger that had one of the batteries burst while being charged and as a result the acid ran down into the charger and got all over the PCB. I took it apart and cleaned it with a baking soda mixture to neutralize all the acid so it wouldn't damage it any further. My problem: The acid ate some of the coating off of the PCB, the green coating, exposing some of the ribbons of lead. What can I use to replace this coating so the ribbons won't be exposed or is this a lost cause?? Please help!! I've searched everywhere and can't find anything to tell me what to do. Thanks in advance.

gizmologist (author)kudzu632016-03-30

If it's just the green coating and not the copper (metal) on the board, don't worry about it. The green stuff is just a solder mask and not necessary to the board's function.

daddywoofdawg (author)2016-01-27

I keep hearing about tining the tip but no one say's how.I tried what I think you do but when I touch the solder to the tip,the solder just rolls/melts off,what I'm I doing wrong?

the idea is to have a shiny film of solder on the tip. If the solder doesn't stick at all, your tip is very dirty. You may have to clean it thoroughly before you can tin it. Unfortunately, cleaning the tip with abrasives will severely shorten the life of the tip. You might try wiping the hot tip on steel wool to see if that helps. if not, you might need a new tip.

If you take good care of your new tip from the beginning, you shouldn't have this problem. Using the tip for anything other than soldering, such as melting plastic, will ruin it for soldering. If you need to melt/cut plastic with a soldering iron, get a second cheap iron for that.

J.W.N.R. (author)2015-05-30

I really enjoyed reading your instructable! Nice humour. Oh, yes, and informative too.

Ever since I got this new 30W soldering iron, I have experienced problems regarding extremely fast oxidation rates. The last picture is of the tip about 5 seconds after cleaning and tinning. That results in the granular joints in the first picture (the imprecision is my own fault...). I am pretty sure the solder I use is rosin core because of the sweet scent of the smoke and the brownish residue on the joints.
I'm guessing the iron may be to hot? Any ideas?

angrypig7 (author)J.W.N.R.2015-08-15

I'm having the same problem with my 40 watt soldering iron. Should have gotten a 25 watt one.

And what I did after getting so tired of wiping my tip on the sponge every 5 seconds, I just bought a few more cheap tips and try not to wipe it every 5 seconds to make the tip shine like a jewelry. And when I'm having hard time transfering heat, I just change my tip :D
The tips makes better heat transfer at shinier conditions but it dosent really matter unless you are trying to do very fine work.

gizmologist (author)angrypig72015-08-15

That's why you wipe and tin just before soldering. And almost any soldering of modern PC boards is fine work.

gizmologist (author)J.W.N.R.2015-05-30
Thanks for reading! Solder does oxidize very quickly on the iron tip. Only thing I can say is:
  1. Make sure the solder is rosin core. If the solder is of questionable provenance, it might be better to acquire some new solder.
  2. That's why I wipe, then tin the iron just before I solder a joint. That way, you have a coating of fresh solder every time.
  3. If you're using lead-free solder, it's going to be much harder to make a good joint. That may be your problem. Get some new 60/40 or 63/37 tin/lead solder and see how that works for you.
The iron is probably hotter than it needs to be, but the only cure for that is a temperature-controlled iron.
J.W.N.R. (author)gizmologist2015-05-30

Thanks! That was extremely quick.

I will find some new solder of unquestionable provenance, then. It is really a pain to make one bad joint after another...

instructible01 (author)2015-07-24

I have to agree that this was a great job. This was a great way to put the best practices down. One thing that has plagued me recently is my tip has become literally solder repellent. I can't get any solder to stick to it when trying to prep it. I have cleaned it with the bronze mesh sponge to no avail. I have read a number of cleaning tips, man uh of which can have detrimental effects on the tip so wondering if you recommend any techniques above others? thanks

ChrisL4 (author)2015-07-23

Thank you for this. This is a great review of the basics plus a couple of tips that I did not know. This will server as a great guide for teaching my son basic soldering!

ChronicSuspicion (author)2015-07-07

Thank you for posting. I've watched and read several of these how-to guides and so far, I really wish I had read this first.

"The purpose of the iron is to get the workpiece hot enough to melt the solder! Melting the solder on the iron and "dribbling" it on the work won't do at all. It just won't stick."

That quote was the perfect way to describe the soldering technique. I am a welder by trade and was able to relate that to oxy-acetylene brazing with a silicon bronze rod..My welding instructor described brazing almost verbatim to that quote and that was my come to jesus moment in learning how to braze.

I'm still lost in space (pun intended) on a few things however. Watching and reading other people's different opinions and techniques on soldering have muddied the water and have me second guessing myself the whole way. The only thing I can do about that is keep practicing and trying different techniques and tools until I figure out what works for me. I know that goes against the grain of your pragmatic approach to soldering but, I have always been of the opinion you can be good at anything but you can't be Great until you know all the ways you can do it wrong. I would describe that as the definition of experience but other people would probably just call that doing things the hard way. Kind of makes me miss the days of having an instructor around that could glance at a joint I welded and tell me where I messed up, what I was doing when I messed up, and what to do differently on my next attempt. I need to tell myself "I think I think too much" more often.

On my first soldering attempt I had left the iron on for about 20 minutes or so without tinning it, unaware that would cause the tip to oxidize because the how-to I had watched and read failed to mention that I needed to tin my tip right off the bat. I picked up the iron, not realizing I already had a problem, thought I tinned the tip properly, and tried to solder two speaker wires together for practice but the iron wouldn't get the wire hot enough to melt the solder. At that point I started worrying that I should have gotten the heavy duty Weller Iron instead of the 25w standard. Or maybe it was the .050 solder wire I bought. The smallest size my local hardware store had was.050

I keep trying to solder the wires together, wiping my tip off on the wet sponge as I go when I realized that was making my tip worse, The local hardware store only had one kind of sponge, a big thick sponge for washing cars. I was actually melting the sponge with to my tip.

No, it doesn't go against the grain at all!

"Good judgement comes from experience. Where does the experience come from? Bad judgement!" Doing things the hard way to start is the best way to learn. Then you practice, a lot. You should always learn to drive a stick shift before an automatic, and learn to use hand tools properly before graduating to power tools. Otherwise, you'll just screw things up faster than you ever could before!

I probably should have mentioned that only a cellulose sponge is suitable for wiping soldering irons. Cellulose burns when it gets hot, but foam rubber sponges melt (Not good!). Or, use the bronze/brass wool, which doesn't need to be dampened.

You can never tin an iron too often. I tin just before unplugging for the day, that way the tip is coated as it heats up the next time. I've seen some folks wrap a few turns of solder around the iron tip while it's cold, before plugging it in. Whatever works.

gizmologist (author)2015-05-24

Always a good idea to pay attention when using power tools...

The Manic Puppeteer (author)2015-04-07

Rocket science involves soldering! So through extremely fallacious logic, soldering=rocket science. Haha.

Yup. That's sort of like saying that because some Rocket Scientists are women, all women are Rocket Scientists...

Hence why it's extremely fallacious. ;)

joeyc3 (author)2015-02-06

legit question, is COPPER wool okay? my soldering iron came with it so I assumed it was okay.. now I'm not sure.

gizmologist (author)joeyc32015-02-07

Absolutely OK. Copper and brass are softer than the iron plating on the iron tip, so many tip cleaners are made of brass or copper wool. Use whichever works for you; wet sponge, copper wool, or other tip cleaners on the market.

Wired_Mist (author)2015-02-03

Nice Tut !

I like how you not only Identified the mistake, but also showed what caused it, and how to fix it. I wish all authors took this approach :P

Wish I had this for Reference when I was learning :'(

bossfish (author)2015-02-02

Very good "ible". One comment is not to use steel wool to polish copper circuit boards. Tiny flecks and microscopic steel dust from steel wool breaks off and may stick to the glass/epoxy boards by static cling. Generally this can not be removed by cleaning except with dangerious chemical compounds, Steel dust can contaminate the solder joint or worse the mounted circuit components which may not be sealed. It also can accumulate between traces and eventually short them out. Even small amounts will enter moving parts such as switches, potentiometers, motors etc., it will degrade the performance and at the least increase circuit noise if not causing direct shorts. I recommend white rubber erasers or very fine scratch pads using non-conductive abrasives. Happy soldering.

gizmologist (author)bossfish2015-02-02

Rinse with warm water and dry with soft cloth and hair dryer.

Poppy Ann (author)2015-01-31

A good instructable only one minor thing you forgot to add that lots of newcomers to soldering miss is once you have cleaned something do not touch it with you fingers/skin all skin has a slight layer of grease and if you touch the part to be soldered you leave a layer of it on the item which can cause a dry joint which can look great but does not conduct electricity.

The reason for the cleaning is to get it chemically clean which removes all contaminants not to make it just look nice and shiny.

but still a great instructable many thanks.

gizmologist (author)Poppy Ann2015-01-31

Disagree for the most part. Finger oil is a volatile contaminant, and will not usually deter a successful solder joint. It's the oxidation that needs to be abraded off that's the important stuff. Chemically clean yes, that's what the flux does.

Poppy Ann (author)gizmologist2015-02-01

if you have been in electrical engineering as long as i have (just over 45 years) you would have come across many bad joints that people had made due totally to the oil in their skin some people tend to generate much more than others which is not good when working with any bare metal from copper to steel any metal that can corrode can suffer.
one place i worked at we had a new guy start and after a few days we were getting a lot more faulty boards back and when we checked 99% of them were items he had done and after watching him work every time he cleaned something to solder he would wipe his fingers across to remove any fillings and that was the cause we started him wearing disposable gloves and it cured the problem, so you can disagrea but i know it is true.

gizmologist (author)Poppy Ann2015-02-02

I too have known a person with highly corrosive fingers. I can only speak from personal experience and I've never had a problem with (my) finger oil and bad solder joints.

HippyNerd (author)2015-02-01

So, what was wrong with my soldering instructable?

gizmologist (author)HippyNerd2015-02-02

Too many 10-dollar words like metallurgy and eutectic. Sounds like Rocket Science, which was exactly what I was trying to avoid. You didn't explain what tinning is. You never explained the most important thing - the bold print in step 6.

I wrote mine for the absolute beginner that just needs to get on the right track and not make any major mistakes, without needing a college course in chemistry. As I said in the intro, this info used to be printed on the back of the package, and didn't explain any metallurgy or chemistry.

I might recommend your Instructable as a "going further" piece, but it just doesn't cover the "basic basics" well enough.

tigerbomb8 (author)2015-02-01

Do not reflow solder unless you are adding more flux..

Fotmasta (author)2015-01-29

I was re-soldering a broken connection on a microphone. The factory solder was so strong it took forever to melt. In the meantime the insulation on the wires melted. I have a 40w iron. The factory must have used chrome and a blowtorch.

tigerbomb8 (author)Fotmasta2015-02-01

Sounds like the tip of your iron doesn't hold much heat.. Next time try a larger tip or a higher powered soldering iron.

Side note: Heat is not the same as tempreture..

gizmologist (author)Fotmasta2015-01-29

It's that miserable lead-free solder. See why I don't recommend it? But you will have to put up with it when doing repairs. Keep an extra blob of tin/lead solder on your tip and it'll make it a bit easier.

belsey (author)2015-02-01

I learned to solder for making stained glass... So now I finally understand why I've never been able to solder circuits! For stained glass you use flux (never rosin core) and you can't touch the lead with the soldering iron or you risk melting it, so you melt the solder with your iron. Harder to control but with practice you can make it neat... Though it definitely doesn't work in tiny electronic scale. One thing you should mention regarding cleaning the iron tip, which true beginners won't know: you clean it on your wet sponge when the iron is HOT. This is obvious once you've done it, but worth mentioning for those who have never tried or seen it done...

blueaxe (author)2015-01-29

One of the first 'ibles I've seen that I really didn't need to add anything. Enough said.

raguiar1 (author)blueaxe2015-01-30

You got the point. Thought the same.

pparker4 (author)blueaxe2015-01-29

you are right on with your critique

pparker4 (author)2015-01-29

thank you so much for your knowledge and creativity

NomadHobbyist (author)2015-01-29

I've been wanting to learn how to solder for a while now, and this made soldering seem more doable. Good pictures, clear instructions, great Instructable!

snoopindaweb (author)2015-01-29

That should cover it. Thank You. ~(:-})

rose_adamaj (author)2015-01-29

Thank you for this! My hubby grew up with a soldering iron in his hand. His father did small appliance repair, built his own radios…. When I asked him to teach me to solder, it, unfortunately, didn't work out. I have muddled along, not knowing how to resolve problems I encountered. I now understand why I've had some of the problems, even better, I now understand how to AVOID the problems. As stuff_and_things said, you don't 'talk down' to us needing this knowledge. I thank you for such a well done, easy to understand ible. And yes, you got my vote(s)!

dgateley (author)2015-01-29

I discovered that museum putty like Quake Hold, which is easily removable, is an awesome adjunct for holding things relative to each other for soldering (or gluing.) Indispensable for butt soldering wires.

Actually I've found the stuff indispensable for all kinds of things where temporary attachment is needed. It sticks to anything, is easy to remove and should be in everyone's DIY kit. One package lasts forever because it is perfectly reusable. A re-use blob of it has a prime place on my bench and never seems to get any smaller. :-)

My most recent use was to hold my upper and lower dentures where I wanted them relative to each other prior to DIY soft re-lining. I:

1) put a dab on the rear molars of my lower

2) push them together to their approximate final position

3) put the attached pair in my mouth and slide them around to get the final relative positioning

4) remove the pair intact, apply the re-liner to the upper

5) put it back in my mouth to form and set the upper re-liner

6) do the same to the lower without separating them.

After both have set up they can be removed, separated and easily cleaned of the Quake Hold by just dabbing a blob against the residue. The result is a perfect air-tight fit that stays air-tight. Hmm, that's probably worth an Instructables article of its own. Feel free anyone that's motivated and has the time.

KrisBlueNZ (author)2015-01-29

This is excellent advice! I've been in the industry 30 years and this is almost exactly what I would say too. I have a few comments, in the same order as the article.

1. Solder is not measured in inches in most countries! You should include metric equivalents for your recommendations.

2. Another soldering iron care hint: don't whack it on something to remove the solder from the tip; this ruins the element! (A well-remembered lesson from my childhood!) Just wipe it on a damp sponge.

3. I don't agree that you need to put a "U" bend in a wire that you're connecting to a pin or terminal. It depends on the circumstances. Keeping the wire against the terminal can be done using "helping hands". As long as the joint is properly formed, it will hold up well against any normal pulling on the wire.

4. If the joint looks dull and granular, it's probably best to remove all of the old solder, clean the iron tip, and redo the joint with only fresh solder.

5. Solder wick is great, a simple desoldering pump ("solder sucker") is great too, and usually quicker for through-hole work.

6. Your advice on SMT soldering is spot on! Tin all the pads first, tack the part down on one pad, make sure it's properly positioned, then solder the other pads and then the first one.

gizmologist (author)KrisBlueNZ2015-01-29

Thanks for your comments!

1. I don't live in most countries. I live in the USA. Sorry if that makes me inch-centric.

2. Good advice. That's what the sponge is for.

3. The U-bend just makes things stay put better. Of course it isn't necessary.

4. If the reason the joint looks dull and granular is because it has lead-free solder on it, yes. If it's a "cold" solder joint, reheating will usually do the trick.

5. Yes. Plated-through holes are a nightmare to desolder, and the pump helps.

6. Thanks. I don't even use the temperature-controlled iron for SMT work. Just my trusty 15-watt Antex.

Wingloader (author)2015-01-29

Take his word for it. DON'T grind your solder tip to a point thinking it will make it more precise. As described, the tip will dissolve and it is a real pain. You then HAVE to grind it to make it usable after a bit of soldering with it. I honestly didn't know this until reading this ible. I thought it dissolved because it was a cheap radio shack iron. THANKS! This is VERY valuable to know gizmologist I the only one who has to click "Make Comment" twice?.

gizmologist (author)Wingloader2015-01-29

The tips are usually iron-clad, but copper-cored. Molten solder is a good solvent for copper. Once the plating is breached, the tip disintegrates pretty fast.

PS... No, you're not the only one who has to click "Make Comment" twice. Maybe it's a feature, not a bug.

KennyH (author)2015-01-29

Instead of steel wool for cleaning, use a white non-abrasive eraser to clean the runs on the board. Don't use the pink pencil tip type because it is too abrasive.

Also, remember that it is the mechanical connection between wires, and between component leads and board, that make the circuit work. The solder simply holds these mechanical joints secure.

gizmologist (author)KennyH2015-01-29

Abrasive is what you want if it's bare copper.

What the hack does your second paragraph even mean? A strong mechanical connection is preferable, but there is no mechanical connection on a PC board. The solder sticks to both parts and conducts electricity. If this wasn't the case, glue would work just as well.

psmcmurr (author)2015-01-29

If you are doing a repair and the solder joints looks dull and granular the solder may be lead free. Look at the silk screen on the board and look for "Pb" with a slash through it and that will confirm that it is a lead free board. The Lead Free has been a requirement in consumer electronics for the EU since 2006 (RoHS). Which forced the rest of the world to go along. The lead free solder has a melt point of 218c, lead solder melt point is 183c. Removing the old Lead Free solder will take more heat and flux. Some of the older pencil type of solder irons (25W) may not melt the solder.

About This Instructable




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