How To Solder: Beading

This is my contribution to the "How to Solder Group", in an effort to get a fancy Instructables patch.

I have fidgety hands and subsequently find it quite hard sometimes to solder small joints, and so I invented a soldering technique I like to call "Beading". It involves making a small ball of lead solder and then placing it on the joint. But there's more to it....I guess...

Step 1 Materials, Tools and other misc crap

My first major soldering project was a robot kit I got for Christmas this year, and I thouroughly enjoyed it, even though it only took me 2 days to complete. It was an "Escape Robot" Link as labelled by the packaging, and involved using infrared diodes that sent out signals which then bounced back off obstacles to the IR reciever back on the robot, in which case it would turn around and start moving again. It was quite interesting, seeing something I soldered and put some hard work into work so well. Of course there was some troubleshooting involving some weak, consequently broken solder points.

'Nuff chit-chat, here it is.

MATERIALS ---
Your usual soldering materials, whatever you're soldering/test pieces.

TOOLS ---
Usual soldering tools, small piece of metal or wood, about 3-4 inches wide and long.

Comments

[Xellers]

I have a soldering iron with a BLACK tip. I don't feel that I've soldered enough to wear out the tip. Am I soldering wrong?

[poushaminkin]

No, you are just either leaving your iron on too high of a setting or you are leaving it on while not using it. You get a brillo type pad you can scour the black stuff off while the tip is hot, but be careful, you can create microscopic gouges in the tip that will lead to a shortened tip life. The alternative is to use a soldering iron tip cleaner... heat the iron and dip the tip into the cleaner. Some say that leaving the tip with a good coat of solder can minimize this effect. Personally, I have been trying to do this, but I naturally wipe the tip almost every time.

[Xellers]

Yeah, I figured that out... You might notice that the comment was a year old. Of course, I don't have a fancy iron with "settings", and I don't have a variac, so I just use the sponge and I use pliers to peel off the black layer.

[Jonny Katana]

Try getting your soldering iron up to temperature and wiping the tip off quickly and firmly with a wet paper towel wad. A surprising amount of oxidation will release with this method.

[mightywombat]

The problem with this technique is that it bypasses the actual metallurgical properties that make soldering work. When you solder a joint, you're making a metallurgical connection. The solder actually flows into microscopic cracks in the metal of the two things that are being soldered together, forming a physical and electrical connection. When you just "paint" solder onto your components, you are essentially just using the solder as glue, and are making a weak and unreliable joint. Soldering correctly requires that you heat the two metallic objects you are joining rather than the solder itself. When the metals you are joining are heated, they allow the solder to flow into the microcrystalline cracks in the metal and create what is essentially a solid piece of metal. You should not melt the solder with your soldering iron, you should heat the components with your iron and melt the solder with the components.

[DYLEGO]

hes right! you will get a cold joint if you use "beading" as you call it. AKA it will fall apart under little strain! and no, you didnt invent it. i used to do it that way, and guess what happened every time? i had to redo the joints 4 or 5 times before they would stay together right.

[m3lt]

Even with very little soldering experience I see a major flaw in what you say. He is using it to solder small parts including electrical components. If you heat, say a resistor, lead to 500 degrees + you will most likely damage the component. The method of heating each component works best when soldering 2 pieces that can withstand the heat...not electronic components. Since the example of the robotic kit was used...the tutorial was based mainly around that.

[DYLEGO]

you are completely 100% wrong. you are SUPPOSED to heat the resistor like you said FIRST, then apply solder. You will get a cold joint if you use solder already on the iron.

[mightywombat]

I hate to have to be blunt here, but you're mistaken. The "method" of heating both pieces is how soldering works. Period. In order to solder sensitive components one would either use a variable-temperature iron, or be very cautious not to heat the component for more than a second or two. Most components can withstand the heat of soldering easily enough if you use an appropriately powered soldering iron - about 25 watts - and don't hold the iron on the component lead any longer than necessary.

The technique that was being described here is actually the mistake that many people who are just beginning to solder make. I made it myself when I first started soldering, but upon reading up on the appropriate techniques and methods, and the metallurgic science behind soldering, I learned I was doing it wrong. As with many things, the so-called "easier" method is often inferior to the "right" method.

When you do not heat both the component lead and the PCB pad to a sufficient temperature to melt the solder, a metallurgic bond will not be created between the two and you will have created what is referred to as a "cold" joint. While it may look like the board and component are joined with solder, and your multimeter may tell you that they are electrically connected, a cold joint can, and most likely will, cause problems with your circuit further down the road. "Painting" solder onto a joint with a hot iron as described is like using tape to fix a broken plate. While it may seem like the two pieces are attached to each other, they are actually just being held against each other by the adhesive, in this case the solder that has cooled around the joint. In order to form a proper solder joint that is both mechanically and electrically sound, the two pieces to be soldered must be heated enough that the liquid solder will flow into the microcrystalline fissures and cracks in the surfaces of the metals, thereby making both pieces of metal one continuous piece.

A cold solder joint may initially seem sound, but will cause problems eventually. The reason that this technique work on larger components that can withstand the heat is because this is how soldering works. If your component is so delicate that it is being damaged when you solder it you need to either replace it with a more robust component, acquire a variable temperature soldering iron, or reassess your soldering technique. Soldering most components such as resistors, capacitors, diodes, LEDs, transistors, and integrated circuits should not damage them. If, when soldered, the plastic of the components case is melting, then the component is being heated for far too long; much longer than should be necessary to form a good solder joint. If that is the case, the possible problem is with the soldering iron. Perhaps the tip needs to be cleaned or replaced, or isn't being tinned properly before making each solder joint.

There are numerous sites online with tutorials on soldering that will repeat exactly what I've said here. Here are a few links:

Instructables: How To Solder
Wikipedia: Soldering
Make Magazine: Soldering Tutorial

[lutherinski]

Hey Mightywhombat, I spent 20 years working in an industrial chrome shop where I learned how to weld just about everything that can be welded, even plastic. However, the most difficult was welding lead anodes which requires one to maintain a very narrow heat range with one's torch. I concure with everything that you have said here although I might add that if you are soldering wires onto electrical connections, you can heat the wire first and apply solder to the wire then heat the do-dad that you are connecting the wire with until the two solder together. lutherinski

[mightywombat]

Lutherinski, You are absolutely correct. This process (for those without 20 years of experience) is called "tinning". It's handy for soldering two wired together, but doesn't really work super well for through-hole components. Most surface mount soldering techniques seem to run along these lines, where you tin the pads (some boards come with the pads already tinned) and then put the SMD component on the pads and heat the leads on the component until the solder flows around them. Thanks for your comment! It's good to have someone backing you up!

[m3lt]

No kidding here... Thank you for the links. As I said I am new to soldering, the method did not sound right. I am going to stay up reading these...been looking for some good guide. Again...Thanks

[mightywombat]

I'm glad I could help. I think I believed that you thought *I* was wrong, from your comment. Now I see you were saying that the process he was describing was wrong. Sorry for the confusion!

[triggernum5]

I won't say this doesn't do the job alot of the time, but its like throwing a basket-ball granny style.. You will often get bad connections, but eventually it'll go.. What I use the wood block/bead for is streaking out very fine solder strands.. Melt a nice blob on the wood, then smear/streak it like paint.. Dropping the molten blob onto a clean friction free surface makes a cleaner solder strand, but then you need to slice up the paper thin solder puddle.. To the instructor: Perhaps attaching the iron to an arm of some sort will help stabilize that enough that you can concentrate on applying solder properly if dexterity is a problem.. I once rigged that up with a rectractor-arm desk lamp, and it worked surprisingly well on easily accessible joints.. (Perfect for surface mount IC's).. I highly suggest you struggle to learn the proper technique.. You'll need it for more advanced jobs..

[tdhg]

Oh...I don't do these computer soldering so I am not sure what is going on and no offense (I can't take pics at ALL) but the pics are a bit blurry. Are these tiny balls of solder? Would these be cool in jewelry making? I can't really tell. Just a question...

[Aeshir]

Yes, they are tiny balls of solder. You wouldn't want to use this kind of solder for jewelry, it's lead (poisonous). Maybe that silver lead or something. You'd have to ask a soldering expert or something.

[jnkarrik]

Resin (or flux) is really what you need to make soldering easy. At elevated temperatures (present during soldering), copper oxidizes quickly. This oxidation prevents the solder from sticking. Flux acts to retard the oxidation, allowing the solder to flow properly. Some solders have flux in the core, so it comes out as it melts. You can also buy small bottles of it with a brush applicator and just paint a little on the parts you are about to solder. It REALLY makes soldering MUCH easier. hth

[Shawster BG]

This method is easy and effective, but can only be used on the more exposed connections.

[Stevolution]

(removed by author or community request)

[CameronSS]

Flagged as utterly non-constructive and uncalled for criticism.

[Aeshir]

Well, really, I don't care. I don't even bother with resin (not exactly sure what it is, maybe that slimy stuff you put on it before you solder). I just solder crap on, and it works perfectly fine.

[mje]

A variation of this is useful when soldering very tiny parts, or working with surface mount componants. One of my projects involves building small preamplifiers inside 1/4" phone plugs and soldering connections to heat-sensitive kynar piezo film sensors, and I do it by holding the previously fluxed parts together, grabbing a tiny ball of low temperature silver solder, and touching it to the juntion of the two wires. This would not work as well using lead based solder, as it's not as strong as the newer silver solders and has higher resistance as well. The lead-free solders sold by Radio Shack work well and are reasonably priced.

[sysadmn]

Aeshir - Here's a positive comment :-). A ceramic tile makes a great solder platform, and can save your kitchen table. If you or a neighbor don't have one left over from remodeling, most hardware stores will sell you one cheap. If you choose one with a shiny (hard) glaze, you can usually pop the solder dribbles off after they cool. If not, they are not hurting anything. I paid $1.88 for an 11" x 11" stone-look ceramic tile. To keep it from scratching the table, you can put felt dots on the bottom, or just set it on a piece of cloth.

[binnie]

i think you should go out and learn to solder properly if you want to wreck your board/ make it look really bad this is the way to go

[Aeshir]

Maybe you should learn to read. It's only for making electric contact. It is NOT for holding a heavy component on. I also REHEAT the solder when I put it on the board.

[rerat]

I REALLY hate to have my first comment be somewhat negative, but this is a horrible idea. The joint wouldn't heat up near enough, there are plenty of fresh tutorials on here for proper soldering technique, you should read up.

[Aeshir]

Once again, from an earlier post: I want to point out that I also remelt the solder when i place it on the joint, making the bead is only for getting the exact right size of solder.

[Aeshir]

I always use this for small joints and it works fine for me. I understand the comment though.

[Ibanezfoo]

I've actually been using this "technique" for quite awhile, but you must mention that the longer the solder sits on the iron the more it degrades. You have to do it quickly or the solder gets very brittle and as others have said, will produce a bad quality solder joint. You can try another method, I believe called solder reflow, that will produce superior results.

[Aeshir]

From a previous post: " I want to point out that I also remelt the solder when i place it on the joint, making the bead is only for getting the exact right size of solder." aight

[mothflavour2]

I agree, solder joints made this way are pretty unreliable. I did this a bit in my Sega Dreamcast VGA mod, and I ended up getting a poor connection on the left audio channel, so I only get sound out of the right speaker. Still, I covered the wire joints with glue on the board, and it seems to be holding them secure.

[mothflavour2]

Okay, when this technique works, it works great, but it's also easy to mess up, so you just have to get the hang of it, and remember that solder joints made like this are for electrical connectivity only. Don't subject the connections to any mechanical stress, as the joints will likely fail.

[Aeshir]

THANK YOU for that. I want to point out that I also remelt the solder when i place it on the joint, making the bead is only for getting the exact right size of solder.

[lemonie]

I found that Fernox (central heating) boiler additive made a really great flux. The main active component was phosphoric acid as I remember. Turns out Fernox also make soldering flux these days...

[Aeshir]

This technique has always worked for me, and I find it works especially good on proccessors. I only use it for very small joints where there is nothing to weigh it down or otherwise break it. PLEASE stop with the negative comments. I realize it's supposed to be constructive critisism but i'm getting a little pissed. -_-

[theRIAA]

isnt this a false joint or something? and learn how to use a camera

[Aeshir]

I can't help it, it's not even mine. See, i'm lacking a little thing called "money".

[ScooterSES]

Yeah, this is likely to give you a cold joint. This is where the solder beads around the joint, but dosn't actually make a good electrical connection. This can lead to all kinds of strange problems in circuits.

[Aeshir]

YAY FANCY INSTRUCTABLES PATCH! We're livin the high life now! :D

[Aeshir]

Sorry about having no pictures, but I haven't gottten around to it, and haven't had anything to solder lately.