loading
Picture of How to Solder
This guide focuses on soldering for the beginner and explains how you can solder a variety of components using a few different techniques - from the classy to the downright caveman. Although soldering can seem daunting at first, once you give it a try you will see that in most applications it's quite simple to do.

Please note: this instructable is written for beginners, and contains lots of very basic information. If you have lots of experience soldering, please use the comments to share your knowledge. Clarifications and corrections are especially welcome.

This Instructable was the lead-off for "How to Solder" month, where we rewarded soldering tutorials with Instructables patches. See the original call for project here at submitting a How to Solder Instructable or just check out all the other soldering Instructables here at the How to Solder group.
 
Remove these adsRemove these ads by Signing Up

Step 1: Tools and materials

Picture of Tools and materials
PICT0009.JPG
PICT0014.JPG
PICT0015.JPG

Soldering is the process of using a filler material (solder) to join pieces of metal together. Soldering occurs at relatively low temperatures (around 400 degrees Fahrenheit) as compared to brazing and welding, which actually melt and fuse the materials themselves at higher temperatures. In soldering the filler material becomes liquid, coats the pieces it is brought into contact with, and is then allowed to cool. As the solder cools it hardens, and the two materials are joined. Soldering is a quick way to join many types of materials, from copper pipe to stained glass. It creates an electrically conductive strong bond between components that can be re-heated (desoldered) if you should ever want to disconnect two items joined together. It's great for joining electrical components and wires and is used in just about everything electronic. In this Instructable I explain how to solder the basics you see in most Instructables: electrical components and wires.

For further information and some more technical specs on soldering check out the wikipedia article.

As with many skills, having the right tools for the job effects the quality of the work being done. When it comes to soldering you can end up using a lot of fancy tools, or just a few simple items you can pick up at the hardware store for a couple of bucks. I am going to use a couple of different soldering tools in this Instructable; there are many ways to solder, and you should use what works for you.

At the very minimum you will need the solder and a heat source to melt it - preferably something small which can get to 600-800 degrees Fahrenheit. If you've got that, your ready to make a connection. That being said, there are a wide range of soldering tools and accessories that can be really helpful if you're going to be soldering frequently. Ladyada has compiled a nice list of equipment and sources to buy the tools on her site. I got together a solid supply of soldering tools by raiding the Squid Labs soldering station. Here is the complete list of what I used...

1. Soldering iron
Most people opt for using a soldering iron to solder. It's a great heat source that heats up and cools down quickly and can maintain a pretty constant temperature. Soldering irons can be purchased from a variety of places. I have picked up some at Radioshack - evil yes, but convenient, some from the hardware store, some from garage sales and a bunch more from retailers online. Low wattage (15-40 watt) soldering irons work best for soldering components on circuit boards while more powerful (60-140 watt) soldering irons work well joining thicker materials like braided speaker wire. If you use too powerful of a soldering iron on a circuit board you might damage the components you are trying to join. I like to keep a low-wattage iron around for detail work, and a high-wattage iron that I can use when I am not too concerned about exposing the material I am working with to high temperatures. It's a real pain to solder thick wires without a powerful soldering iron.

The soldering iron in most of the pictures is made by Weller, and has a variable temperature control. This is the best of both worlds since you can set the heat exactly where you want it, but it's significantly more expensive than fixed-temperature irons. If you're just going to do some occasional soldering it isn't a must have by any means. Anyone interested in modding a soldering iron should check out DIY Hot Air Soldering Iron by charper.

2. Solder
There are lots of kinds of solder available. They come in different thicknesses from around .02" to some really thick stuff you would only use on copper pipe with a butane torch. You use thin solder for detailed work like putting resistors onto circuit boards and thicker solder for joining larger materials like speaker wire. I use solder around .025" for most jobs. Most solder is made from a combination of tin and lead - it's about a 60% tin, 40% lead mix depending on what solder your using. Recent international health codes from Japan and the EU (California and New York have adopted similar policies as well) mandate that lead solder be phased out of certain commercial products and substituted with a lead-free alternative. The manufacturing deadline was this past July so we should be seeing the changes now. Even if you don't live in California or New York its still worth staying away from lead solder since lead has been known to cause all kinds of a nasty health effects from birth defects to severe developmental and neurological damage. Plus it's pretty easy to find the lead-free stuff.

Some solder will contain a small amount of silver. This pushes the melting temperature up a bit, but the silver helps the solder to flow and makes a stronger joint. If you are worried about burning whatever your working with, try to stay away from solder with silver in it, but it works very well if you're just joining wires or something that won't be easily damaged. The last thing to know about solder is that you want to use a solder that has a rosin core. The rosin acts as a flux when soldering and helps the connection - it's also the kind that's most readily available at the hardware store and from electronics suppliers.

3. Soldering iron tips
Soldering irons come with a tip, so you don't have to go out and get a special one, but it's important to know the differences between them and make sure you're using the right tip for the kind of soldering you're doing. Some small-wattage irons come with conical pointed tips for detail work, while most high-wattage irons come with a flatter screwdriver-style tip that works well on wires. You want your tip to be a little smaller than whatever you are soldering so you have good control of what you heat up and what you leave alone.

4. Soldering iron holder and cleaning sponge
It's nice to have a safe place to put the soldering iron down in between soldering. A soldering stand safely holds the iron and gives you a place to clean the tip. Some soldering irons come with their own holders. If yours doesn't have one, you can buy one or make one. jaime9999 has a Homemade nearly-free Soldering Iron Stand that is pretty much identical to what you can buy. The stand isn't a necessity for learning how to solder, but it does help.

5. Tools to work with wires
I have a go-to stock of tools that I round up when working with wires or electrical components. They consist of wire cutters, a wire stripper, needle nose pliers, and an automatic wire stripper (courtesy of the Squid Labs soldering station.) The automatic wire stripper is really convenient if you're going to be stripping lots and lots of wire, but by no means necessary. I have stripped lots and lots of speaker wire using my teeth (not the best idea, I know I know.)

6. Clips to hold your work
Often called "third hands" or "helping hands," these little guys help a whole lot when soldering. You have to hold the soldering iron with one hand and the solder wire in the other, so it really helps to have something else to hold the components you're actually trying to join. You can use alligator clips, clamps, or even some tape to hold things in place if you need to. The third hand is generally a good investment if your going to be soldering regularly, and there are plenty of Instructables with with ideas to modify them if you do happen to pick one up. Check out: Make a 3 degree of freedom 'hand' to help with soldering / gluing work and make your 'helping hands' 100x more useful for soldering / gluing small parts by leevonk to start.

If you would like to make a set of helping hands of your own there are already a number of good Instructables on that too. Quick helper for surface-mount soldering by http://www.instructables.com/member/bikeNomad/bikeNomad, QuickMods - Soldering Arms by Aeshir and Build a Pair of Helping Hands by john otto should get things started.

7. Exhaust fan
I do most of my soldering at a soldering station that is equipped with an exhaust fan. It's really not such a good idea to breathe in solder fumes, and soldering does produce fumes. Any kind of ventilation/fan you can rig up will help. Vent the fumes outside or use an indoor fan with a filter if you can't vent them outdoors. Here is a Window-mounted solder fume extractor (not just for RVs!) posted by bikeNomad. Also check out Dr. Solomon's low tech, but functional Solder Fume Extractor if you're looking to build something that you can place right on your table. If you're just doing a quick soldering job, the fumes wont kill you by any means. I have certainly done my fair share of soldering without a vent, but anyone doing repetitive soldering should definitely pick one up or make one.

8. Safety goggles
I hadn't ever used goggles before while soldering, but while doing research for this post I saw it mentioned elsewhere and agree that its a good idea. Little molten bits of solder tend to fly out of the soldering joint when you're feeding in the solder, and if it landed in your eye it wouldn't feel too good.

9. The materials that you want to join together
I was just messing around, and mostly soldering for the purpose of this Instructable so my materials didn't necessarily make anything. You can solder wire, electrical components like resistors and capacitors, circuits, breadboards, electrodes, small pieces of metal and whatever else you can think of. Don't know if it can be soldered? Give it a try - you won't blow anything up.

Once I have got my tools and materials rounded up, I like to pretend that I am a pilot and begin my pre-flight/solder checklist.

Step 2: Getting ready

Picture of Getting ready
PICT0021.JPG
PICT0059.JPG
PICT0062.JPG
PICT0038.JPG
Once I get my tools rounded up I like to plug in my soldering iron and let it heat up while prepping my materials.

First things first, the tip of the soldering gets hot - up to 800 degrees Fahrenheit, so don't touch it. I know this seems obvious, but many people seem to burn themselves at some point while soldering.

If you're using a new soldering iron you will want to put a small amount of solder on the tip of the hot iron before you start working. This is called tinning the iron and you only have to do it with a new iron. Once you start using it will usually have some solder on it already and be ready to go.

Once the iron reaches temperature (some irons take minutes to do this and some irons take seconds), I like to clean the tip of my iron on a wet sponge. You can wet the sponge on your soldering base if you have one, or you can just use a damp sponge or steel wool. Gently touch the tip of the soldering iron to the sponge and clean off any old bits of solder that might be stuck to it. It will sizzle a bit; this is normal.

I asked Mitch, a soldering expert who works at the control tower by day and is numberandom by night, for some tips. Mitch showed me a good idea for how to hold solder wire: he cuts a piece of it off the roll, and then makes a coil at one end with a short lead at the other. This helps him hold it steady and apply just the right amount of solder. This is a way better idea than trying to hold the whole spool of solder or grab onto just one thin strand.

Next it's time to pay some attention to the material you're soldering. If you're soldering wire, you'll need to strip back about 1/2" of insulation to expose the bare wire. If your joints are going to be wire-to-wire or wire-to-lead, you can twist them together tightly before soldering. Electrical components placed on a circuit board don't need much prep work; just seat them where you want them and find a way to hold them in place with clips or by bending the leads outward slightly so they stay put when you turn the circuit board over.

Finally, place what you want to solder into the clips on the helping hand, or on a surface you don't mind getting a little burn mark on - scrap wood works well. Basically you just don't want the components moving around on you when you go to solder them. There are lots of ways to orient the wires/components so you don't have to hold them in place while you solder them. Find what works best for you.

Hopefully your soldering iron has reached temperature by now, because you're ready to solder!

Step 3: Soldering wire

Picture of Soldering wire
PICT0050.JPG
PICT0057.JPG
PICT0060.JPG
PICT0054.JPG
I started soldering just two pieces of wire together because it's the most forgiving way to learn. You can't really get the wires too hot - the insulation might start to melt a bit, but you're not going to hurt the wire.

With the wires you want to join twisted together and held in place, pick up your soldering iron in one hand and your solder in the other.

Touch the tip of the soldering iron to the wires and keep it there.

The wires will begin to heat up. At some point over the next 2-10 seconds (depending on how hot your iron is) the wires will be hot enough to melt the solder. You can touch the solder to the wires (not to the tip of the iron!) periodically to see if it's hot enough. It's tempting to just touch the solder to the tip of the iron and melt it right away, but don't! You will end up making what's called a cold solder joint. This occurs when you melt the solder around the joint, but you aren't melting the solder into your joint or onto your components to make a good connection. It's much better to wait the few seconds and melt the solder onto the hot wire itself.

If you touch the solder to the wire and it begins to smoke and melt, the wires are hot enough. Add the tip of your solder to the joint as necessary. You want to introduce enough solder to cover the wires, but not so much that you create a big glob of solder at the bottom of the joint.

Once you've got what you think is enough solder on the joint, pull the solder away and then remove the soldering iron. If you're using a gun style soldering iron like I was, release the trigger to turn it off. If you're using the kind that doesn't have a trigger the iron will stay hot, so just place it back into the holder.

Here is a video of wire being soldered. The whole process happens pretty fast, and isn't nearly as complicated as you may have expected.



Here is a close-up video of the same process.



Step 4: Soldering components onto a circuit board

Picture of Soldering components onto a circuit board
soldering still 2.jpg
Up until pretty recently I spent most of my life soldering speaker wire and crossover components for speakers. This meant mostly wires twisted around wires or big resistor leads twisted around inductors and capacitors. At that level soldering doesn't really get any more complicated than what I did in the previous step. Lots of the projects on Instructables, however, use smaller electrical components and circuit boards, so I figured I would give that a try too.

Soldering on a circuit board takes a little more care and attention, but it's still very doable. I pushed a few of the leads from some spare LEDs and resistors that I had from my LEDs for beginners post through some open holes in a circuit board that was lying around. I soldered the leads onto the bottom of the circuit board where the electrodes push through. This is called through hole component soldering.

To solder the LEDs and the small resistors to the circuit board I switched to the adjustable temperature soldering iron. The tip was smaller so it would be easier to get the solder right where I wanted it, and using the soldering gun on a circuit board is probably way more heat than necessary and it could end up damaging the components. I set the temperature of the iron to 675 degrees Fahrenheit and waited for the tip to heat up. I then loaded the circuit board into the alligator clips and got myself ready to solder - iron in one hand, coil of solder in the other.

When soldering leads into circuit boards you want to heat the metal contact on the board and the lead itself. Applying too much heat can damage the circuit board or even your components. The surfaces being joined in this application were much smaller than the twisted wire, so things heated up a lot faster.

I touched the tip of the iron to the crack between the lead and the metal pad on the circuit board. After waiting a couple of seconds, I dipped the tip of the solder into the joint and placed a very small amount of solder at the connection - no more than the head of a pin or so.

Once the solder pooled a bit and soaked into the joint I removed the solder wire and then the iron. I remove the solder a second or two before I remove the iron so that the tip of the solder doesn't get stuck to the joint. The solder begins to harden as soon as you remove the iron.

Using the proper amount of solder is more important while soldering small components on a circuit board than when soldering wires. If you apply too much solder and it pools up outside of the metal pad, it can cause a short. Too little solder and your component won't make a good connection with the circuit board and might not work the way you want it to. When you've got the right amount of solder it looks like a small ant hill that forms right at the base of the lead and the circuit board.

Here is a video of the process.


Step 5: Cutting the leads

Picture of Cutting the leads
PICT0042.JPG
Once you've got your components soldered into the circuit board, you can go back and cut off the excess leads. This is pretty easy to do, and there isn't much technique here. Just a few quick tips before you snip:

It's best to use a sharp wire cutter that has just one side of its cutting edge beveled. This way you can get a smooth flat cut when you cut off the lead.

It's also a good idea to cut the leads pretty close to the circuit board to minimize the risk of creating a short.

Although I didn't do it in the video below, holding onto the excess lead when you cut it off is a good way to keep the little ends from getting all over the place.

Once you've got your leads cut you're pretty much done with soldering and ready to move on.

Here is some riveting video of the leads getting cut off:


Step 6: Surface mounting components onto a circuit board

Picture of Surface mounting components onto a circuit board
PICT0080.JPG
PICT0083.JPG
PICT0090.JPG
Soldering components onto a circuit board when the leads can be pushed through holes in the board is the easier of the two methods of soldering small components onto boards. Many circuit components need to be surface mounted on circuit boards, which forces you to be a little more precise then when you can work on the bottom side of the board.

To solder something onto the surface of a circuit requires a process called tinning. Tinning is when you apply a small amount of solder onto the materials you are joining before you connect them. In this case, it involves putting some solder on a contact on the surface of the circuit board then attaching the component to the solder pool. Mitch showed me how this process is done.

First he touched the tip of the iron onto the small pad on the top of the circuit board. He then introduced a small amount of solder onto the pad and took the iron away.

Then, a few seconds later he picked up the component he wanted to solder with a set of tweezers, heated up the small glob of solder that he had just placed down, and gently lowered the contact on the component into the pool of hot solder.

He took the iron away, held the component in place a few seconds longer, and released the component from the tweezers.

He then went to the other side of the component and finished making the connection by soldering the remaining two contacts together.

Surface soldering is done like this because you need to lower the component into place by hand, so it's hard to hold the iron, the tweezer and the solder all at the same time. Additionally, tinning is just a good thing to do while soldering small components. I didn't tin the wires before I soldered them because they were so big I was sure I was going to be apply enough solder to make a good connection. However, when soldering small components or doing surface mount soldering like this, tinning can be really helpful because you basically already have your solder applied to your pieces before you go to connect them. There is no need to glob on more solder and run the risk of getting it in a place where you don't want it to be.

The picture series below shows the process unfolding step-by-step.

Step 7: Soldering with a lighter

Picture of Soldering with a lighter
Everything that I have explained how to do up until now has hopefully been pretty close to how things should be done "the right way" when soldering. Soldering, however, is just a process of joining things together to make a connection. If you don't have all the tools to solder, but still want to learn how to solder something, never fear, with just solder and some wire you can practice bare bones soldering.

Bare bones soldering comes in handy when you're stuck on a desert island and you need to make a repair to your headphones so you can watch the sun go down while being serenaded by your most recent whale songs cd. It's also a cool trick to pull off next time your decide to be MacGuyver for Halloween.

I took some pieces of wire and stripped them with my teeth - the best method for doing this I have found is use my molars. I just grab the insulation with my teeth, try to sever the insulation a bit, and then pull on the wire. It's easiest to do with braided wires, and it certainly takes a little practice to apply the right tension so you don't just rip the wire apart entirely. But once you get the hang of it it's actually a pretty functional method. (WARNING: I do not encourage stripping wire your teeth at all, and it will probably lead to expensive dentistry work if you do it enough.)

Once I had the wires stripped and twisted together I got a lighter and a bit of solder and went to work heating up the wires I wanted to join. It took the lighter about as long to heat up the wires as it did when I used the iron. I then fed a little solder into the joint, continued heating the wire to smooth things out, and then turned off the flame.

It worked just as well as it would have had I used an iron. Of course it's harder, if not impossible ,to use this method on circuit boards, but it sure does the job on wire. I have heard that using matches also works well when soldering wires.

Here is some video of bare-bones soldering with a lighter.


Step 8: Desoldering, fixing mistakes and extrapolation

Picture of Desoldering, fixing mistakes and extrapolation
Desoldering:
Desoldering is the process of removing solder at a joint to disconnect two components, wires or materials. You might have to do this if you want to replace a component that's gone bad, or if you want to change something about your design once it's already soldered into place. To desolder wires you can usually just heat up the connection and wiggle them around until they come free. Better yet, if you have the slack, just cut the wire at the connections, strip, and resolder as necessary.

With leads that are mounted through holes on a circuit board it takes a little more finesse. To desolder something delicate its best to use a desoldering pump, or bulb which will actually suck up the molten solder and remove it from the joint. Soldering wicks or braided copper wire also work well to suck up unwanted solder. For more complete guides on desoldering check out Make Magazine's Learn How To Solder Skill Building Work Shop Video and this site here.

Fixing mistakes:
Soldering is pretty forgiving, and its usually pretty easy to fix a mistake. If you put down a little too much solder or position something incorrectly you can usually reheat your joint, melt the solder, and then reposition your component as necessary. Solder can be heated and cooled as many times as you need to get your joint the way you want it. So don't be discouraged if it takes you a couple of tries to get it down - you will still end up with a good connection if you stick with it.

Extrapolation:
Soldering is a pretty straight forward process but there is no limit to what you could create with it. Try to join things together. It works well for making jewelery, doing basic arts and crafts with small metal objects, or re-wiring your toaster into a heating element for an infra-red sauna. If soldering has been keeping you away from experimenting with circuits or making a project, hopefully it doesn't have to anymore. Once you do it a few times you might even start to enjoy it.

If you would like to get started on a few basic soldering projects check out instructables user Makekits and the Make Magazine Store to build things like a MiniPOV or a Daisy MP3 Player.

1-40 of 359Next »
oneoff7 months ago

Thanks for the guide! I also wouldn't recommend stripping wire using teeth. Some plastic wire insulation can contain lead. Here's a CDC account of someone getting lead poisoning from chewing the plastic: http://www.cdc.gov/mmwr/preview/mmwrhtml/00020984.htm

He chewed the plastic wire coating for 20 years and has a slight lead poisoning in the article. That's a huge difference from biting off the tips and spitting them out.

Lets not go overboard comparing apples to planets.

sjones9810 months ago

Hi I've just finished a little soldering project but unfortunately its not working, I've just read your comment about not reheating solder, which I think I did a few times, how crucial is this and could this be the reason my circuit won't work? do you think I should start again? Thank you

IMG_2328[1].JPG

@sjones98 Hey there. Fixing that wouldn't be a problem. I've reheated solder many, many, many times on the same project while I was learning and I never had an issue. It cleans easily, remelts cleanly and often looks 10x better when I'm finished. The best advice I could give with regards to fixing your soldering is to do one small area at a time. Reheat the solder and wick most of it away, make sure you are using the right kind of solder. Find some that is specific to electronics. It will have mostly a silver base as opposed to lead and is very thin. A thin point tip on your soldering iron will help as well. It keeps the solder neat and reduces the solders habit of spreading to other holes.

When you are ready to resolder your board, only use a very tiny amount of solder. It takes barely any to make a nice solid connection. It's human nature to want to gob it in, because more is better right? In most cases, no. Just a dab will suffice. The right amount will surround the pin and be barely larger than the hole.

I hope this helps! Cheers.

I see that this is a bit late but the problem seems to be the soldering done on the board. There are a few areas where leads seem to overlap, which, of course, causes short circuits. I'm not the greatest at soldering myself, and I've done worse quite a few times; sometimes involving unpleasant explosions.

mchazlitt14 days ago

FLUX...the secret of flow

eldon.rv1 month ago

One very undersold product at the Shack was the Velleman kits. I've done a couple of them, and they seem more like useful items than the Arduinos and Bone stuff. For example, Velleman had a USB breakout kit you could build that gave a variety of real world contact closures and sensors out... and in. I have a couple of them going in a remote control project or two where you can uVNC to a PC somewhere, and turn things on and off, take readings, and so forth for equipment nearly a hundred miles away. I didn't have to learn an entire micro-language or buy/build complex processors, masks, and all that like it appears i would have to with Arduino. I dunno about the rob you clean bit... I'm old enough to think of names like Heathkit, Archer, Optimus, Uniden and the like in Radio Shack stores. Yes, sometimes expensive... but nearly always rebuildable and nearly all that stuff I've bought over the years is *still* running.

Like my Optimus 100X6 Tuner Amp. yup. 6 big transformers in it and it drives 15" drivers to about 128dB @ 35 - 12k frequencies.

RadioShack may rob you clean most of the time but I've had a pretty good experience with them about a year ago. We were writing business letters in my English class, and we could send them to a business of our choosing. Running out of ideas I chose to send to RadioShack. About a month latter my English teacher told me that a package from RadioShack was sent to the school to me. So I got the package, and inside it was a letter saying how they appreciated a young person being interested in electronics and DIY. Also inside was an Arduino Mega 2560, Skull Candy earbuds and a radioshack T shirt that isn't available in stores. The letter was handwritten, and signed by about 1/4th of the mail dept. Ever since then I've had respect for the store.

DonL52 months ago

As a soldering instructor, the one thing I see often is people not knowing about the importance of FLUX. If your solder is balling up, not flowing where you want it, not gripping the wire, pad, or component, its because you did not use flux. The rule is that "solder follows flux". When flux is applied, and heated with the soldering iron before applying the solder, it does several things. It creates a thermal coupling to transfer heat quickly to the area you will be soldering, it removes and impurities and oxides that are on the metal surface, and it prepares the metal to bond with the solder. If you apply solder without flux, it can be easily removed by chipping it off or by vibration. If you apply flux first, your solder joint permanently bonds with the metal. It cannot be chipped off and even heating it again and wicking the solder off will leave the surface coated with solder because the solder is permanently bonded with the with the metal. For electronics, the recommended flux to use is RMA, which is a mildly active acid flux. It becomes active only when heated and the acid etches the metal allowing the solder to bond to the etching. Be sure to quickly clean the flux residue off and clean the solder joint.

bitsandbots2 months ago

Nice work! Very detailed.

great instructable. thanks!

ageorgia3 years ago
Hi, this "through hole component" soldering is exactly what I've been trying to do. The DC jack on my laptop is broken, and I've been attempting to fix it. But for the life of me, I can't get the solder to behave the way yours does in the video, where you get the "ant-hill" shape.

When I do it, the solder either balls up on the end of the solder wire, or bunches up into a little blob around the lead, which is only a good enough joint to last for a week or so before I start losing the connection again. (I had the exact same problem while I was soldering the pickups in my guitar as well, although that was soldering a wire to a plate so it was quite different.)

So can somebody please tell me....WHAT am I doing wrong??
schans ageorgia7 months ago

I would check that you have a soldering iron that will heat up high enough first. It sounds like the components you are attempting to solder never get to the proper heat to allow the solder to flow. Heat is crucial. To much and the solder is not controlled and to little it will not stick to the components. Make sure you are applying heat to the component you are trying to solder and not the solder itself.

Ive had this problem myself and have found it to be that the contacts you are trying to connect are dirty and you probably need to flux them.

Hope this helps
pfred2 ageorgia3 years ago
Just a guess but you may be trying to solder lead devices with lead free solder and equipment. I don't have any experience with the lead free stuff myself but I hear it is hard to work with. Maybe someone else can shed some light on this?

I cannot see what you are doing but it sounds to me like your iron tip is not tinned properly, or it was, and it is dirty now. Something like that. Take a paper towel fold it into a little square and soak it with clean water, then wipe your hot iron tip on it with a rolling motion a few times see if you can make it shiny bright.

You should be able to get a droplet of solder to stick right to your iron tip. If you can't do that you can't solder. Well, not you can't solder, just you can't solder with that iron tip.

When you solder to a metal plate it is helpful if you sand the smooth metal with emery or sand paper to put some scratches in it that the solder can grip to. Solder won't stick to all metals either. Like you can't solder aluminum. Well you can solder aluminum, just not with regular solder.

Confused yet? Good! I think that is how they want us to be.

Insist on genuine lead solder!

http://i.imgur.com/l1z0g.jpg
davidbarcomb8 months ago

Great guide for beginners. Thank you for doing this

Bradlez926 years ago
what should we do if we want the melted solder completely removed from the circuit board altogether? you mention some sort of pump, but that sounds REALLY exspensive and convoluted, when there is probebly a much easier way.
A less scary term for a desoldering pump is a "solder sucker." They aren't any sort of complicated pump for fluids, and can be as simple as a little rubber bulb with a plastic nozzle coming off of it. The ones I prefer are tubes with a nozzle on one end, a plunger in the other and a spring inside to push the plunger out quickly, sucking the liquid solder in through the nozzle.

In my experience solder wick works better. Put the wick on top of the "boo boo" and apply your soldering iron. You may have to move down to fresh wick and apply heat again to get all the solder. I have heard that braid from coax cable can also work for this although I have never tried it.

http://www.radioshack.com/product/index.jsp?produc...

Available at RadioShack although probably cheaper elsewhere.

Have a hunt for 'solder wick' or a desolder pump - that will do the trick and is extremelly cheap! Even Maplin sells it!

PCB Police Electronics Forum
do they last forever?
So, how does one use 'wick'? is it the obvious just wipe up the solder with it? or maybe there is a long convoluted ritual involving worship and dance steps, even voodoo!?
If the "wick" is anything like a desoldering braid, then you usually just lay it across the join you want to remove solder from and heat the wick up, the solder will just flow into the braid like you were tinning a wire. In general, I've had much better luck with braids than solder suckers/pumps.
thanks kitsune and franklin i found out how to afterward, online, but i still appreciate the answer and yes, i've learned there is different wick for leaded and unleaded solder and they aren't interchangeable thanks again
radio shack braid only works on leaded solder it worked fine for me but some kid who was using lead free(for school, i brought my own solder) and it didnt work
fd93 Bradlez926 years ago
desoldering pump/iron combos are less than 15$ at the evil ones (radio shack)

O.k., I didn't read all of this because of time constraints, but I'm really anxious to to so. If there is one thing I'm lousy at is soldering. I'm lousy at a lot of things, but this is a pain in my neck. I have one of those cold soldering guns that you can touch and won't get burned. Will your system work with them? I can't get the darned thing to work. See, I'm lousy at this stuff. I have regular soldering guns, too, and am geeked to get them do what I want. Thanks in advance!

The biggest mistake people make soldering is they fail to clean what they are trying to solder before they solder it. Everything involved with the soldering process has to be bright, and shiny before you solder. Dirt, oxides, and oils all need to be removed from whatever you are soldering prior to trying to solder it. Emery cloth, Scotchbrite, steel wool, or a wire brush may be used to clean, and brighten conductors prior to soldering them. A solvent may be appropriate to use too. Soldering iron tips should be wiped off immediately before using them to solder a joint as well.

Make sure your soldering work is soundly mechanically connected before you solder it too. That way the joint will remain immobilized until the solder solidifies. Other than that feed solder into the joint, not the iron, and it should all work.

woodswalker6 years ago
I bought a 30W soldering iron from Radio Shack. I'm having a lot of trouble because it takes as long as 90-120 seconds for the solder to heat up. And if I don't touch the solder directly to the iron, it never gets hot enough at all. Plus, the solder doesn't flow well and it turns into balls & blobs. I'm puzzled. What's wrong?
I know this is an old post, but someone may benefit.
There's a few possible problems, the obvious one is you're iron isn't hot enough. I prefer a 40W iron over a 30W any day. It seems 30W are the most common, but they just don't cut it for me.
Try a cheapo model form ebay etc for $5 or so and see how it works for you.
Another fix is to heat the iron up a bit with a torch. I rarely need to do this to boost heat, but I will use a torch as the heat source for the iron if I'm too far from an outlet..

The other problem could be thinking the flux inside the solder is enough. It is not.... At least it has never been for me. You need to flux the surfaces and be sure the surface can be soldered in the first place.
The surface could be coated or plated with something that either the solder or the flux doesn't like. It might also be corrosion, a lubricant, protectant, or who knows what. In those cases I clean it with a chemical such as electric contact cleaner aka brake cleaner, or even carb cleaner, but most people use alcohol. If that doesn't work then it's probably some kind of coating you'll need to remove with force, like sandpaper or a Dremel tool to break thru to the good metal. Once you've ground the bad part off, clean it, coat it with flux and try again.
If it's still being difficult you can try using sandpaper on it while it's coated in flux. I like 320-400 wet/dry paper, maybe 180-220 if it's really bad. Cut a small piece for sacrifice because you don't want to use it again now that it has flux on it. After you have either roughed it up nicely, or ground thru the problem coating whatever it was, clean it, flux it, and try again.
I prefer to coat the problem item in solder first, that way I know it'll work when it's time to attach something. Assuming the iron is hot, clean, and will hold solder (plain old rosin core 60/40 works best for me), put a little on the tip, then apply it to the surface and hold until it flows and coats your surface. If it's a large item and you can't get it hot enough you will need to preheat the item with a torch or whatever, I've used anything from little butane torches to my oven, as long as everything can handle the heat that is. (fyi; preheating also works for welding when the machine can't generate enough heat). Once it's hot enough the solder will flow nicely into the area worked on, and your problem is solved.

If you never could get the solder to stick then you might be working with the wrong metal, like aluminum, so use the appropriate method for that metal, or simply try using a screw or bolt as a contact. If you can figure out what the base metal is, then search the net for a bolt material that will not react with it. Example; drill a hole and use an appropriate bolt/nut and torque it down good, then apply solder to the bolt's head which should be a snap. Common steel bolts are usually coated with something which probably needs to be ground off. Grind off just enough area for what you need, and preferably solder it in a way you can still use the tool to remove it if needed. Now flux your spot and apply a little drop of solder like described above. Being a bolt it's probably heavier and may need a little boost with a torch.
I flux/solder each piece first so I know they're both good to go, then I put them together and add a drop of solder with the iron until it flows.

I hope this helps some people with their soldering problems...

Chevota

I would probably avoid using brake cleaner then applying heat, because depending on the formulation you can emit phosgene gas:

http://www.advrider.com/forums/showthread.php?t=48...

Thanks, something to think about. I don't think you can buy that kind of brake cleaner anymore, plus it evaporates almost instantly when cleaning stuff like that. I do remember spraying the older stuff on something red hot and the smell was horrible. Not sure if it was that particular gas, but omg it was bad!

Speaking of solder, I lost my old solder and flux in a move so I bought this new solder and flux, some "safer" crap or some bs but it was all I could find. I haven't been able to solder anything but clean copper wire and that barely sticks together and often fails. It's horrible stuff. Maybe that was the original posters problem? I guess I'll have to buy some from china on ebay or something.

Lead free solder melts at 218 deg C where leaded melts at 183 deg C. You may need to get a higher wattage iron to work with it. That thanks to the EU which started this lead free mess.

I've always preferred a higher heat than what most people use, for example I won't use a 30w, only 40w at min. I don't know the exact temp but to get the same effect from the adjustable solder station at work I need 800F/426C. Others at work used 700-750F and they struggled. This was back when we used real lead and flux btw. So I don't think 218C would work at all, but whatever the case I'm well above it. I've even tried boosting the temp by heating my iron with a propane torch, but it doesn't help. My latest project needed tabs soldered to rechargeable AA batteries to renew a cordless tool batt pack. I've done this in the past with lead 60/40 and acid flux no problem, but the new stuff refuses to stick to the batts. It's like trying to solder to glass... Very frustrating. My flux might be part of the problem so I will look for a different type. I may have to spot weld the tabs like the factory does, but it doesn't help me with other stuff.

sand the battery contacts, and make sure the battery is getting hot enough. it's a very difficult thing to do, getting something like that hot enough without getting it too hot. also, reheating it over and over, trying to get it right, will probably negatively affect the battery life and capacity. practice on one set to know exactly what you need to do, before moving on and doing it right on all the rest.

Yes, I have done this many times for decades on all kinds of projects with no problems. Then I lose my old 60/40 lead and "good" acid flux and have not been able to solder a single battery since. I plan on trying spot welding next, unless I get lucky and find my old solder & flux. This new solder makes everything much harder btw, but it made the battery thing impossible.

toxdoc thekanester12 months ago

A soldering iron is nowhere near hot enough to convert a chlorinated solvent to phosgene. Think arc welding or oxyacetylene temperatures.

Chevota toxdoc12 months ago

Someone brought that part up because I said I used brake cleaner to clean parts that have grease/oil on them, then if the part is too big for the iron to heat you can preheat it with a propane torch. Not so much about the part getting too hot, but putting a torch on a the surface still wet with cleaner. Not a common circumstance, nor do I believe most cleaners sold today are an issue, but something to consider. Plus if you do manage to create the gas, which I think I might have once or twice, it's too nasty to breathe anyway.

my molten solder sticks to the soldering iron

clean it off extremely well, by tinning it and wiping it on the sponge. multiple times, if necessary.

or, you may simply not be getting the material hot enough. when the thing you're soldering is hot enough it will suck the solder off the iron. if you've never seen it, you may not believe it or be able to imagine it, but i promise you, it's like a sponge touching the edge of a water droplet... the solder literally gets sucked onto the metal when it's hot enough.

also, your iron may not be capable of getting hot enough, if it's really old or if the tip is damage in some way. if the tip is damaged, you could just replace it and see if that works. if the iron is so old it doesn't heat up enough, you'll just have to replace it.

1-40 of 359Next »