Posted by tosmatos 2 days ago
Ask HN: Resources to get good at soldering?
Right now I've busted a board, and managed to desolder and resolder a stick but the controller doesn't turn on anymore. I'm doing this all by myself, and I think I'm following good advice (ventilation, good iron tip, using flux etc...).
But there are many variables, and a lot of experts have different opinions on stuff. Does anyone know good resources that I could use for getting good and making less mistakes ? Thanks.
A small USB-C soldering iron supported by IronOS[1], e.g. Pinecil vor TS100
A solid stand with brass wool
A KU soldering tip (looks a bit like a knife) for good heat transfer, too small tips are not good
Thin (<=0.5mm) solder wire
No clean flux (not a pen)
Isopropyl alcohol
Solder fume extractor (DIY is OK, if you're building it right) is good for your health
Solder mat (blue silicone)
Multimeter (not too cheap, around 20 bucks)
Self closing tweezers
Normal tweezers
A wirecutter (blue 5 bucks from ali express)
Manual Desoldering pump (engineer ss03 or a clone for cheaper)
Most important is cleaning (alcohol, then flux) and heat transfer (tin your tip, your pads or your wire before putting things together to ensure good heat transfer). Cleanup nicely and tin your tip after soldering to prevent corrosion.
Optional but helpful for more professional tasks:
Hot air station
Auto Desoldering pump (ZD-8965)
Adjustable power supply (fnirsi usbc, 30 bucks)
Oscilloscope (mini beginner with display Cost around 30 bucks)
Capton tape
Solid Copper wire
Maybe a bit over the top for a lot of situations. I assume folks would acquire these things over a long period of time depending on their projects or what they are repairing. I have a 2-ch function generator coming because after 20 years of bodging stuff together and fixing minor things, I am tired of using the super cheapo one I got back in the day. It takes a while to amass all that crap, but it's fun.
A couple other thoughts: used hemostats are super helpful for a lot of things. for a lot of years I avoided getting any kind of "3rd hand" because I would use combinations of hemostats.
Or jigs- I have a very old piece of wood that has hole drilled for m and f XLR and 1/4 audio connectors with notes about which pin is which. Making tools like that is quite satisfying.
I really enjoy having a stack of stainless steel condiment cups to put screw in- I stack them up during a disassembly and then unstack them as I reassemble.
Also I will say that while I thought building one of those cheap-o oscilloscope kits was a pretty fun practice and I can recommend that, I don't fine them easy enough to use for beginners... the 2-ch Rigol scope I got was not super expensive and felt like the cheapest thing I'd be recommending to folks.
Finally, I have had a lot of mixed successes with desoldering pumps. It took me a long time to figure out that I can only get desoldering braid to work if I put liquid flux on it, but that made it a lot cleaner for me than the solder suckers.
Not supported by any open third party firmware usually, but that's fine with me.
One thing to watch out for is tip grounding, some cheap irons leak a few volts at micro to milliamp level power, relative to ground, which could matter if you solder very sensitive things that are grounded, which you probably don't.
DIY fume extractors are hard to do, you need powerful fans unless you have an arm to put the extractor right above the iron. Also remember that when it's just sitting in the stand, it will still smoke for a few seconds, so the extractor must cover that too.
Those thin wispy activated carbon pads probably aren't doing much, you need actual particulate filtering like a HEPA or similar, but almost anything is better than having the smoke directly in your face with no fans.
Disclosure: Old person. ;-)
Also, 63/37 tin/lead "eutectic" solder is the easiest to use. Wash your hands after using it, or wear gloves. 60/40 solder is almost as easy, and cheaper. Lead-free is more difficult, especially for learning. Learn with lead solder, then switch to lead-free.
Wearing gloves and washing your hands five million times is more annoying than just using lead free.
And even with perfect precautions, the flux expands and makes it spit tiny little balls, which then contaminates your whole work area with a somewhat fine dust.
But in a non-occupational exposure setting you're not likely to have issues if you solder occasionally even with lead solder and don't take any precautions.
Yes, but buy several. Maybe it's only because I buy cheap crap ones in the first place, but I treat them as consumables.
Kapton tape
What gets you good at soldering is just practice. Solder a lot. A fun and easy way to do this is to pick up those cheap ($5 or less) electronic solder-it-yourself kits and do a bunch of them. Include ones that contain small surface mount parts.
You can also practice desoldering on them, or pick up broken electronics and desolder parts from those.
> managed to desolder and resolder a stick but the controller doesn't turn on anymore.
There's a chance to practice repair (which is a completely different topic from soldering)! Odds are very high the problem is that you've made an unwanted solder bridge or you have a cold solder joint.
Yes. There's repair, rework, build and debugging.
Repair is mostly diagnosis, followed by cleaning and repair of mechanical damage. ICs themselves don't fail much. That's what the original poster is doing.
Rework is mostly careful desoldering followed by new component installation. That's when hot-air rework stations are needed, if you have to replace ICs. This is a "use the right tool for the job" task, where you have little metal heat gun air guides for each IC shape. (I have a bag of those things.)
Building, where you start with a blank board and a supply of components, all with a known-to-work design, is just small scale manufacturing. It takes some skill and training, but the process is simple and repetitive. It's automated in production shops.
Debugging of new board designs requires not just soldering tools but the test equipment to test the thing and an understanding of how it works. This is what electrical engineers and technicians do.
Other thing that got me: no-clean flux residue plus a cheap iron with a bad ground can look like a dead board when it's just leakage. Clean it with IPA and a brush and retest before desoldering anything else.
Every next solder makes you better at soldering.
Get through your first 1000 solders as soon as possible, and then keep going. The rest will figure itself out along the way.
https://www.robins.af.mil/Portals/59/documents/technicalorde...
I was a 2M Mini/Micro repair technician for a few years in the Navy. That book was our school and manual.
My friend Jim's been soldering since the 1950s. We solder a lot of things with leads, for this, his method is to get each item to be joined tinned, then use solder as a mechanical joint. Melt in the solder, remove the iron but hold them together, then once cool, tug on the joint to make sure it holds.
Please have a look at PACE soldering/desoldering videos on youtube. They are dated but very good in general. You don't need a lot of videos, just the basics. https://paceworldwide.com/video/basic-soldering-lesson-1-sol...
You don't need to spend a lot of money so I'll keep it simple:
Get yourself a few kits of SMD soldering components and practice. Amazon, AliExpress, whatever.
Some notes on technique:
You will be surprised at the tip size that works well - usually slightly larger is actually better, just need to get comfortable with the angle and size.
Have a magnifying lamp or something like that to help you see better.
You should always use alcohol (70-99% IPA) and flux. Clean everything properly, then flux it, then solder it. Then clean after you're done. Have a few flux pens on hand. MG Chemicals sells these things. You can also get the bottle version and some empty bottles with syringes that mount on top.
Using a "shoe" iron tip is nice because you can angle it between the lead of the component (through-hole) and the pad, and this gives you a little entry way for your solder to flow. The flowing, hot solder will then naturally heat up the rest of the pad. This is a thermal mass effect.
The alternative of having the iron tip on one side of the lead, and the solder wire on the other is not bad either. This makes the solder "flow" across the pad, but it does mean you don't get the thermal mass effect of the first approach. You may need to do this in tighter spaces. Regulate temperature wisely.
For through-hole components, most often the hole itself is plated so it is a double-sided pad, give it an extra 0.5-1s for the solder to go to the other side appropriately.
Make sure you have small wire cutters and nose pliers. The nose pliers are very handy when you need to shape the leads of transistors or chips that have 4-5 legs exactly to the through-hole positioning. Not usual, but not uncommon to see staggered layout.
You will make mistakes. You won't know what you are doing because no amount of tutorials can help here. We have all busted boards for various reasons. Just don't electrocute yourself on high voltage capacitor banks.
Also, flux is your friend.
There are probably some great videos on soldering on YouTube, luckily it's a mature field so not much has changed!
Some random tips...
Lead solder is easier to work with, but with lead free make sure you are using the right flux and temperature.
It helps to preheat things as much as you can. You want to have a hot pad and hot lead, then add solder to that. As opposed to putting a blob of solder on the iron and trying to apply it like glue.
Too much heat can damage the board or part of course.
Use the right tips. Fatter tips can help more evenly apply heat.
If there is a lot of copper like a ground plane, it can take longer to heat.
Watch for cold joints!
Just overall think about getting the parts you want solder on hot, touch solder to it, remove heat.
Don't eat it!
It's probably not gonna be 100% shiny, that's fine, it just has to wet effectively instead of just kind of hovering in a blob.
Lead free is the only thing I use unless I'm repairing some old pre rohs era thing I guess, but I generally don't encounter many of those.
Also, good tools and supplies- kester solder and liquid flux.
It took me quite a while to figure out that my preferences are for desoldering braid that's been soaked with liquid flux- if I use a manual pump it's going to be rough. I am hoping to get a hot air station at some point but I haven't been doing enough work to justify it over my ancient hakko.