How to Solder Videos: Why is soldering difficult sometimes?

Picture of How to Solder Videos: Why is soldering difficult sometimes?
This is another "How to Solder" instructable, but it also attempts to get at why soldering doesn't go easily sometimes. On the following pages, there are also numerous pictures showing good technique, good and bad joints, and some tools of the trade that you may not find in your local RadioShack. If you've ever wondered what wattage iron to get, the 3rd step has a video showing how some irons of different wattages fair on a couple soldering tasks.

Here is my list of the top reasons soldering doesn't work well (looking forward to your opinions on this):

1. Soldering tip has oxidized (turned black) and solder won't stick to it. This happens when the tip is left bare while on--a naked tip will quickly oxidize at hot temperatures. The best advice for preventing this is to glob solder on the tip every time you set the iron down. Weller (high-end iron manufacturer) actually recommends holding solder against a new tip the first time you turn it on so that the solder will melt and cover the tip the very instant the it gets hot enough. One of the best guides out there that emphasizes tip care: Weller's HowTo

2. Bad technique: applying solder to the iron, letting it sit there for a while, and then trying to carry it over to the joint. If you let the solder sit on the iron, the flux quickly boils off (the fumes are from flux, not the lead). And without flux, soldering becomes almost impossible. Flux removes oxidation from metals, and it's crucial because solder won't stick to oxidized metals, and metals oxidize very quickly at soldering temperatures.

3. Not enough heat: A 15 Watt iron is fine for small chips, but any larger connectors or wire bigger than 16 gauge will cause problems. 25W-30W is probably fine for most hobby applications. Is there any risk to getting a 100W iron? Wattage is separate from temperature, right? ... depends on the iron. Watch the video on the next page.

4. Dirty or oxidized parts: Bare copper oxidizes relatively quickly (this is why most components are tin / lead coated), so older parts or bare copper that has been exposed for only a week or two can require a light sanding (pink erasers are great) or stronger flux.

Shameless plug: This instructable is an except from a larger guide with many more pictures found here: There is also a desoldering guide, a review of the cold heat iron, and advice for choosing solder / flux types. And, of course, a store to buy stuff :)

Thanks for any corrections / feedback.
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Justin Lam5 years ago
i have an 80W soldering iron with a chisel tip (Weller brand) that i bought for $20, but i find that it's too hot and the tip is too thick. Could i stick the tip in a lathe and grind it down so it's like a cone shaped tip, or would that ruin the tip? and when i was soldering connections on a plastic battery pack, the plastic started melting..... should i just get a cheaper soldering iron with less watts? (author)  Justin Lam5 years ago
I've answered your question here:

I'd be happy to answer followup questions on our forum.
Too bad the link results in a 404 error message. I understand that being an instructor or a student at a tech university, a small business partner, and life in general forces one to manage their online time. Having said that IMO it isn't cool to direct responses to comments that include questions and reader of those  who also may benefit s from the answer away from  an instructable. (author)  static4 years ago
sorry, we changed our site structure a bit...  corrected link:
404 again. You ought to consider setting up some permalinks that redirect to the correct location when your site changes again. (author)  earlye3 years ago
We decided to take the forums offline. If you notice any other bad links to our guides I'd be grateful to know about them.
Great, thanks. Not knowing what you recommended a held off in pointing out some tips are plated and sanding or grinding them will ruin them. In the event your group ever revise your instructions that would be something to include. along with that "loose" tips can cause problems. My suggestions to =D where going to be to get an iron in the 40-45 watt range and get a new tip for the 80 watt iron, and make sure it was tight when installed to see if it will tin, if not use a light dimmer to make a simple control to reduce the heat, to see if will tin then. The simple control will turn that 80 what monster into a dual purpose iron, and will be usable for any iron purchased in the future. Nawadays the digital readout infrared thermometers. make calibrating the simple temp controls much easier.
thanks a bunch! I'll just go out and buy those el cheapo soldering irons, one of them i found for $8 and it's from my favourite electronics part store, so i'm sure it's fine. thanks again!
CameronSS7 years ago
Where can one get one of those desoldering pumps for relatively low cost? I checked eBay, and they have a huge selection of three.

Also, beautifully done Instructable. Should this be somehow added to the How to Solder Instructable? (author)  CameronSS7 years ago
Added it to the "How to Solder" group. Thanks for the compliment and suggestion.

That desoldering tool is great (and over $600), but for occasional stuff the RadioShack iron with a bulb works great. If you really want one, the cheapest place that I've seen equipment like this is Madell Tech--here's their page of desoldering irons. I actually prefer wick / braid since it's easier wipe up every last bit of solder with that. Shameless plug: you can get it here.

Tip: If you do get one of the vacuum desoldering tools, sometimes it's helpful to add more solder to the joint first because they're most effective when they can create a strong vacuum, and it's hard to create a strong vacuum over a mostly clear hole.
I'm still in awe of that pump, and still trying to figure out a cheap version. What if a vacuum pump were attached in place of the bulb, and a hopper set up to catch the solder? Is that basically what the fancy version does?
My guess is any vacuum source could be used, even a home vac., with a chamber behind the tip to catch the cooled solder and a screen between the chamber and vacuum line.  Post an intractable of what you try. My spring loaded solder sipper works for what I need for board repairs. My board component salvaging methods aren't elegant, so I don't need a pump for that. (author)  CameronSS7 years ago
The fancy irons do indeed have a hopper of sorts to catch the solder, but I'm not sure how it's integrated with the vacuum line, etc. One problem with those things is that you constantly have to use little cylindrical files to clean out the tips. It'd be neat try hacking up that radio shack thing, attaching a vacuum and screen and trying it out. I suspect the airflow will prevent it from getting how enough. But if you let it heat up for a while without air flow, and then only cut it on when the solder is molten it might work. A lot of people have made cheap hot air pencils out of that by attaching a fish tank pump tube to the bulb and blowing air through the tip. This did not work for me at all regardless of every permutation on tip shape and "stuffing" that I put in it. The air temp was never hot enough.
I know exactly what you need. It's the radio shack desoldering pump model #64-2098. I own and there great, plus they only cost $9.98. I highly recommend this if you want a good low cost desoldering pump.
As a person who has had hit and miss luck with soldering, I am happy I stumbled upon this video. Your video helped me to realize all the mistakes I have made in the past, I still have a way to go I'm sure but this is an excellent start. Thanks!
jethrow8155 years ago
Question, I have a new Weller 40W chisel tip, using Oatey 40tin 60lead rosin core.

Cant tin the tip if my life depended on it.
 the solder just rolls off the tip in little perfect balls onto the mat

any ideas?

thank you~

corsi5 years ago
bravo well done. the videoo helped alot. it is easy to get lost when there is only text. good job i learned how to solder properly now.
Donnn5 years ago
YOU are the MAN !!! I can and do solder quite a bit but you have really done a great job of explaining the reasons for all the innate things we do to get a good joint ... and the why not toos as well this is by far the best Ive seen...
lost20105 years ago
wish i would have watched b4 attempting to mod a perfect 60$ 360 controller :( my iron is like lumpy and brown and has actually formed a hook shape some how.
guy905 years ago
Great video! thank you
caredo5 years ago
Thanks for this. I'm brushing up on the basics again and this really helped. It also helped that the narrator for this video was easy to listen to and wasn't droning in a monotone. Very well-done.
i kinda think thats too much solder
Could you elaborate on why a smaller is better? Just to save solder? From my understanding, as long as a majority of the pad is connected with solder, and the angle the solder makes with the surfaces is less than 90 degrees, all is well... Would love to hear additional information.
if you make the blob too big you have the risk of connecting ajacent ones, a short circut is not good and will cause problems and it doesnt look good so it would probably be good practice to make blobs just big enough to make the connection so you dont cenect things
i found a de-soldering pump at the pound shop
were can i get the solder vacuum
MikeDaMan5 years ago
wow this answered most of my questions! Thank you soo much!
Like2Learn6 years ago
I didn't know much about soldering at all, until I watched this video. It was great. Now i just have to figure out what all to get to get started.
YES! finally! why couldn't all the other tutorials I've seen be so simple yet so helpful thanks great 'ible
buckaroo1696 years ago
Wonderful set of How-To-Soldier videos. I've been doing these procedures for about 30 years. It took me a decade or so of trial and error and research to get this much information. Although it does take lots of practice. KUDOS to you guys!!!
cd416 years ago
Haven't soldered once wanted to find out about it before i jump in(i do have a iron though!)
hydrnium.h26 years ago
Thanks for all this help, I just started Soldering and I've been having a hell of time trying to figure it out.
kbitz6 years ago
Cheers man, fixed my noobish soldering :D
andrew1016 years ago
even though i solder alot this is very helpfull. alot of it i knew butit gave me better teqnique
johnpombrio6 years ago
Auto-Temp 379 soldering station. I found that 90% of my troubles soldering is that the iron is NOT HOT ENOUGH. When I finally sprang for this dirt cheap station, ALL of my issues went away!
timmy1234s6 years ago
so should i get a soldering station that goes from 5-40 watts or 5-80 watts. I am going to use it for general use and for circuit boards. Also, the station can be controlled, it is the WLC100 from Weller (author)  timmy1234s6 years ago
40W will def. work for most things. 80W would only be needed for very large wires or circuit boards with lots of layers, and even then 40W would probably work, just a little slower.
Thanks. By the way, do you think the tips that are included in the Weller WLC100 soldering station would be sufficient to do general soldering and circuitry? (author)  timmy1234s6 years ago
It comes with a .125 tip, which is good for most things, but you might also want a 1/16 tip for close together circuits. btw, we have a soldering forum:

Thanks. This instructable is good and thanks for the info.
Kaiven6 years ago
So if I need to add flux, when do I add it? (author)  Kaiven6 years ago
usually the flux contained in the solder is sufficient, but it can be helpful in surface mount soldering to help solder wick into place that has already had its flux boil off. See our SMT soldering video
I asked because my solder doesn't have flux in it. Old stuffs.
kog1036 years ago
First off, brilliant Instructable, it is extremely helpful. Secondly, instead of using the alcohol dispenser and pump to clean the joints, could you use alcohol wipes instead? (author)  kog1036 years ago
If you have any other questions, feel free to drop them at our forum:

your question at our forum (author)  kog1036 years ago
Cleaning usually requires some vigorous brushing followed by wiping up with some alcohol wipes, otherwise you're really just spreading around the flux residues. Alcohol wipes or any other lint-free wipes are fine. And actually, unless you're making something requires high reliability, you probably don't need to clean off the residues.

Okay, cool, thanks.
ProjectZro6 years ago
wow thanks i always "knew" how to solder through trial and error eventually i got to the point were i had no problems BUT i never knew the mechanics nor chemistry of it . thank you for the help and you may have single handedly expanded my career. (author)  ProjectZro6 years ago (author)  ProjectZro6 years ago
Could I post your question on our soldering forum for others to read?
Shagglepuff6 years ago
THANK YOU! Iv,e always been 'solderly challenged", but now, I might be able to do this.
Kiteman7 years ago
My first thought when I read the title was Why do I want to solder videos?

Now I've read it, though, I'm impressed. Well done, that man.
Derin Kiteman6 years ago
JJrulz6 years ago
hey thanks for the instructable, very helpful. wow you are so pro at
pburgess6 years ago
If there were a Nobel Prize for Instructables, this should win it. Thank you for clearing up all the mysteries of soldering I've puzzled over for years! (author)  pburgess6 years ago
thanks! If you're feeling generous, putting a link somewhere that points here or to our site would be awesome :)
mushfiqc6 years ago
i just got a soldering iron from Home Depot and i didnt clean it ( i got it 2 days ago) can u tell me how i can clean off the black gunk thats building up? (author)  mushfiqc6 years ago
the black stuff is most likely flux residue. Usually a wet sponge is all you need to clean it off. Try adding more solder to the tip and then wiping it off repeatedly--the flux in the solder will help to remove the oxides. If this doesn't work, you can buy special "tip tinners", and if that still doesn't work, some fine grit sand paper may be the only hope. But be careful, most soldering iron tips have a this protective iron coating that covers a copper core. If you pierce this outer plating by grinding or sanding the tip the inner copper will quickly erode when exposed to solder.
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(removed by author or community request)
Some other people asked for a DVD, so if you're interested: How to Solder DVD. It includes the video above in higher resolution as well as our surface mount soldering and metal working videos. All our videos can still be streamed at for free.

And speaking of clamps, we sell those, too :)

Mr. TiKi7 years ago
I am new to soldering and I think your videos are great. They where very well done. Couple of questions. Do you primarily use lead based solder? Also I see that you were soldering what seems to be resistors. If you make another video in the future can you show how to solder components together on a board? (author)  Mr. TiKi7 years ago
First, thanks. All the soldering done in the videos was with lead-based solder. Lead-free solder can be slightly more difficult to use, as it melts at a slightly higher temperature and doesn't cling to metal as readily. Also, the joints will come out looking duller and grainier, but this is purely cosmetic. Just fyi, the key to lead-free soldering is having clean parts and a good quality flux (inside the solder). I recommend Kester if you can find it. The soldering that takes place around 4:00 min. in the video on the first page is on DIP chips. I'm not sure I get what you mean by 'solder components together'... can you give me a specific example?
I am in awe of the high quality of your instructable, and your video. Congrats. I was going to make a instructable on how to solder, but I will just use yours. Give yourself a High 5.
Thanks for the reply. I mean like if I wanted to solder a resistor to an LED on a prototype board how would I go about doing that? (author)  Mr. TiKi7 years ago
If your proto board looks like the picture on the first page, put the leads you want soldered through adjacent holes, solder each individually, then try to heat both at once and add some solder in between. Some proto boards already have copper traces between holes. Hope that helps!
Yes thanks
whatup.dub7 years ago
Great info. I really liked the labeled pictures of the good joints and the info on what exactly was wrong with the bad joints in step 3. I've been trying to pick up any info on proper technique I can find. Good tips.
sardines4547 years ago
very instructional, great job
technick297 years ago
Bravo! Stupendous Instructable, perfect for any beginner up to a professional. I learned much from this guide. (author)  technick297 years ago
ramcosca7 years ago
Okay, what is that first thing on the video? Is that vacuum-like noise part of the vacuum desoldering tool? I had never heard that when someone was using a vacuum desoldering tool... (author)  ramcosca7 years ago
There are two noises in the video: one from the general exhaust system that sucks away solder smoke, and the other from the desoldering tool--the buzzing sound that starts midway. I'm not sure if the noise is typical for that brand of device or whether it was just clogged up a bit. It's an OKi brand shown in the last picture. Do you have a particular brand / model that you like?
Not yet, really. I have yet to start to buy my tools to start with my electronics projects. I don't know about brands that much. The only thing I know is that I have to stay away from the cheap RadioShack irons... but just that. Do you recommend OKi? Is it good? (author)  ramcosca7 years ago
Oki is on par with Weller, and you'll find their equipment in a lot of production environments. I don't recommend that kind of equipment for personal use mainly because of the price (just about everything they make is $600+), and the requirements just aren't the same. Those things are designed to work 8 hours a day, every day, have all sorts of anti-static protection, precisely controlled tip voltages, have tips that heat up in under 2 seconds and are quickly changeable... lots of things that are nice but maybe not necessary. You can't beat RadioShack's price, but here's my 2 cents on their irons: After about an hour, the handle starts to bake your hand, and after a week or two of use, the tips start to become loose and wobbly. Best advice right now is to get a Weller 25-30W iron. If you're planning for the long term, the next step is to get a temperature controlled iron. I'm not sure what type/ brand to recommend for that yet, our company is in the process of reviewing some cheaper hobbyists irons now, I'll let you know when we complete.
ramcosca7 years ago
Thanks! I needed a good explanation about flux and how to correctly solder! It's this semester that I will finally get into electronics and doing stuff like this. Awesome vid.
Neodudeman7 years ago
Wow, that was very pro. That definitely helped improve my understanding about soldering.
highonlove7 years ago
WOw man that was great that helped alot im trying to learn how to sodder and my gran parents dont know how to and that help alot THANKS!