SMD work with gas soldering iron?

LichtAn · 2018-08-11T18:37:05.000Z

Hi, any thoughts on this doing SMD work? Like unsoldering and soldering smd components? There’s a hot blower head included and you can regulate the heat.
https://www.dremeleurope.com/general/en/dremel®versatip-471-ocs-p/
I don’t want to spend a lot of money on a dedicated SMD rework station. But if it’s crap to work with and I might end up killing the parts, I will ditch the idea.

duramax · 2018-08-11T18:39:43.000Z

I use a hot air SMD rework station and it was not that expensive, afaik 30 $ from overseas. very handy tool to have for building drivers.

LichtAn · 2018-08-11T20:17:01.000Z

So it’s not recommended to use a gas soldering iron? I could also get it for cheap. It’s like 40 euro.

duramax · 2018-08-11T20:26:48.000Z

checked the link - you could, in theory, work with SMDs with this tool. The brand is well-known and reliable (I have their smaller drill for woodworking). Gas= portable, which is good for work on cars, R/C hobby, …

However, with a hot air SMD workstation you can:

- adjust for temperature (exact temp)

- adjust air flow (pretty cool feature, also accurate)

- have more power

- get other/cheap tips

- no need to buy/fill gas

should be cleaner/with no smell
It is not portable though, at least not the cheaper stations.

IMO you should consider your main tasks and then see whether you need a portable solution?
At the end of the day it depends on what you are trying to do. Soldering drivers i.e. is ideal on a skillet or hot plate.

moderator007 · 2018-08-11T21:46:51.000Z

If you need it portable then its probably great. If not then the rework station would be better and has a lot more benefits.
Being able to adjust the heat at the solder tip is a huge plus for making soldering easier, especially smd work.

LichtAn · 2018-08-13T16:34:11.000Z

I’ve probably watched a dozen soldering videos on Youtube today and got to work again on an old PCB. Desoldered a bit, stacked some SMD resistors and soldered back some ICs in place. Soldering is such a frustrating experience for me, well at least SMD soldering.
I’m wondering why some people choose iron soldering over paste + hot air when it comes to SMD. Is there any good reason? Wouldn’t it always be much easier to just have your components held in place by a bit of paste and just reflow them with hot air?

duramax · 2018-08-13T16:47:54.000Z

It depends on what exactly you are going to do. Youtube videos don’t tell you how many years the person has been doing this and also not how many attempts they had before uploading the video. Soldering or reflowing is something that improves with practice, and I mean a lot of it.

Building 1 flashlight is not enough practice to be good at soldering. Components on drivers are tiny and, regardless of technique, things will eventually go wrong. You drop a part and it disappears, airflow was too high and everything gets blasted away, parts were misplaced or are in the wrong direction or simply switched, and so on.

The easiest way for me to build a driver was to use solder paste, place the parts and heat it on a hot place. Done in a few minutes. Exchanging FETs or other parts on a working driver was more difficult.

Hot air is way more convenient if you know how to do it (you know what temp you need and which air flow and how long to hold the air at what distance). You’ll get the hang of it after a while…

LichtAn · 2018-08-13T17:28:40.000Z

I try a bit of everything. I’m trying to be prepared for whatever may come my way. Watched a video of drag soldering an IC. Think to myself: “Hey that looks easy!” I end up with solder connecting the first two pins and the rest is without any solder.
I’m even in a constant battle with the desoldering wick. Sometimes it works like a charm, sometimes it gets stuck. And I never really know what I’m doing wrong, neither do I know why it worked, when it worked.
I’ll let it rest for today…

duramax · 2018-08-13T17:35:07.000Z

Let me tell you something really funny: I studied Electrical Engineering and I was pretty much the only student who wasn’t that great at soldering. Took a break for years (and never worked as an engineer, at all) and now, all the sudden and with the help of forums like BLF, my skills have improved a lot. Still not there yet, but my boards no longer look horrible.

I think you should build a few lights, take a very old PC and desolder components on the motherboard, disassemble old devices and you’ll be alright after a while.

LichtAn · 2018-08-13T19:05:27.000Z

I need to start practicing the flashlight relevant stuff a bit. Spring bypasses, stacking smd resistors, reflowing LEDs and so on.

moderator007 · 2018-08-13T19:18:49.000Z

The right tools help a lot. A rework station, helping hands, good solder, good flux and a magnifier headband.
You can choose brand of any of these tools. This is just the stuff I use.

LichtAn · 2018-08-13T20:14:18.000Z

moderator007:

The right tools help a lot. A rework station, helping hands, good solder, good flux and a magnifier headband.
You can choose brand of any of these tools. This is just the stuff I use.

Went on a shopping spree this month and pretty much have everything I need. Got some good solder paste from Edsyn on the way and will probably get some flux from them also.

vt2nv · 2018-08-13T20:39:57.000Z

Honestly, and no offense intended, but if you’re asking this question you probably shouldn’t make the attempt. SMT rework requires a different touch that hand soldering does. Please consider practicing with stuff you don’t care about before you rework stuff you do care about. I’ve made a good living over the decades repairing devices that customers attempted to repair themselves. I’m just saying. And if you prove me wrong that would be a good thing. I love happy endings

Cheers

moderator007 · 2018-08-13T21:31:22.000Z

LichtAn:

moderator007:

The right tools help a lot. A rework station, helping hands, good solder, good flux and a magnifier headband.
You can choose brand of any of these tools. This is just the stuff I use.

Went on a shopping spree this month and pretty much have everything I need. Got some good solder paste from Edsyn on the way and will probably get some flux from them also.

If any one of the things listed (except maybe the headband) isn’t that good, then the whole job will be harder and not be as good. Solder and flux probably being the most important with the right temp. Oh and your going to fail sometimes but keep your head up and keep trying(hopefully you don’t trash something to expensive .) . Practice makes perfect.

Lightbringer · 2018-08-13T23:33:44.000Z

moderator007:

Oh and your going to fail sometimes but keep your head up and keep trying(hopefully you don’t trash something to expensive .) . Practice makes perfect.