Need an iron and solder recommendations for some thru hole synth kits. Leaded or lead free for a noob?
As far as lead vs lead free goes:
Lead boils at 1749 °C (3180 °F). You will not be inhaling any lead vapors ever. Your equipment would melt and you would die from the heat before the lead vaporizes. Regardless of which you choose, the most immediate health hazard is flux fumes! All flux is poisonous! You will need fume extraction regardless! I will talk about this more later. As far as lead poisoning goes, the primary pathway will always be oral ingestion (excepting unrelated cases like lead tetra ethyl, aka leaded gas which is still used by small aircraft AVGAS). So, always wash your hands after handling any lead and do not eat or drink at your workstation (take regular breaks to drink water). This is equally important when handling flux, so don’t assume that using lead free solder means you can eat at your workstation. Another important thing is cleaning up. Always wipe down your workstation when you finish up. You will need to clean up all of the solder splatter and flux drippings, so I recommend using 90%+ isopropanol. This is where the leaded vs unleaded really matters, as putting lead in your trash can isn’t great. You won’t necessarily be poisoning your local water supply with the small amount of waste you’ll make, but every little bit adds up. I personally think you should get some experience with leaded solder first, as it’s easier to use, but look into switching when you can.For fume extraction, the easiest way would be a fan and an open window. I usually use a small fan with a carbon filter that I bought for cheap like 10 years ago (I regularly replace the filter), as I only do small hobby stuff and I only get a month or two a year I can stand leaving the windows open where I live, but there are better options.
While it will increase your initial costs, I recommend only ever buying ESD safe equipment. I’m assuming synth boards and guitar pedal boards have a lot of overlap, so you will eventually be soldering semiconductors onto the boards and you will be pissed the first time it doesn’t work because you fried it. I have a cheap silicon ESD mat I do my soldering on, an ESD safe Weller soldering station (discontinued model, but you need temperature control), metal helping hands, ESD wrist straps, and an ESD tweezer set. Definitely get some nice tweezers eventually as the shitty ones made me want to throw things.
Some nice to have items are alligator leads and test equipment. I highly recommend a good multimeter (I’m bourgie and have a Fluke, but you don’t need to spend that much) at the very least. It can help make sure your components are good and working at spec as well as diagnose which part you messed up. A decent power supply can be useful, but I don’t get a lot of use out of my cheap FNIRSI one. I intend to get an oscilloscope eventually, but they’re generally either expensive or shit. Honestly, the best piece of troubleshooting gear I have is a length of instrument cable that I put a 1/4” jack on one end and the other I soldered together the jacket to hook alligator leads to and made the core into a probe (just a length of wire I soldered to the core and then heat shrinked a bit of dowel near the tip to stiffen it). I plug my guitar into the pedal input, then I plug the jack end of my homemade probe into my cheap guitar amp, clip the jacket to the board ground, then poke the probe end around to see where the signal gets lost.
Speaking of, get a heat gun and some heat shrink. It comes in handy. Also, get a flux syringe. I can’t tell you how much easier it is for solder to flow when there’s a little too much flux on the joint. You’ll need to clean all of the excess flux off at the end. For that, I start with an acid brush (they’re cheap in bulk) and isopropanol, then spray it with a can of contact cleaner. Some lint-free rags are very helpful as well (I acquired mine from work).
Otherwise, have fun and don’t burn yourself.
That's a great point about ESD protection. I have a esd mat for when I'm rearranging stuff in my case but i didn't realize that same thing applies to the soldering iron itself. Is that a common feature or so i need to search for it specifically?
It’s pretty common, but anything that is ESD safe will advertise as such.
You will probably want a set of "helping hands." The old-school ones are garbage. Get one with a metal plate and magnetic clips you can move around.
I would recommend pinecil soldering iron to you. Best 26 Bucks I've ever spent.
While I agree, I think it's important to note that you also need a high wattage USB C power supply to go with it, so a bit more than $26 at the end of it if you don't have one that works already.
Good to highlight, though eho doesn't have a PD C charger at home these days? Just plug the one from your laptop, switch, etc.
Seconding this. I use pinecils. Excellent soldering irons if you don't need super-rugged durability.
pinecil and leaded is slightly easier/less brittle if there is stress, but you can self-own without good ventilation (not that lead is easy to evaporate, but just shit lying around, so wash your hands before and after. ventilation is still needed due to flux, but it's roughly cigarette smoke harm). tht is kinda easy to solder and doesn't have stress, so i would get lead free, but take care about ventilation
if you are attaching something like free copper wires to pcb, i would go leaded and deal with it. just take care about cleaning up each time and not having food anywhere near soldering place
I kind of get the impression that for someone in a garage doing a handful of boards a year, the benefits of lead solder outweigh the personal risk/environmental impact, but it's hard to get any real information online
easily yeah, lead free is not that bad, but it has higher temperature to deal with and being worse for wetting. personal risk is being a dum-dum about washing hands or getting food stuff involved on the same table, environmental is also like don't throw it in a trash, and especially when you get better, you won't have a lot of wasted solder
if you are doing it in a garage, gentle fan to remove flux fumes from your breathing area is fine, just take breaks to vent it out
I'd argue that the minor inconveniences of lead-free solder are far outweighed by the health advantages.
but it's industrial scale where they are clearly bad, like giant basins of melted solder or ball placement thingies, and then in the trash where lead leaches out into environment, lead doesn't evaporate that easy. in placing stuff on boards it's probably equal, for copper wires, maybe i just suck but i have to try a lot to get it attached with lead free solder, it cools too quickly (i'm also doing on needs basis every 6 months or so, not a professional or anything)
Get an iron that supports C245 tips, (something like this: https://www.aliexpress.us/item/3256809574765991.html) a lot of irons these days are still ceramic core, which is very old and inaccurate. Leaded solder, using unleaded to start with will make you want to tear your hair out. I recommend having nitrile or latex gloves to use while working. Get some liquid flux. Fume extraction is preferable.
What are the benefits here over something like the pinecil? I've just got a handful of kits to do
I've never used the pinecil myself, it might be perfectly fine for your purposes, I just don't want to recommend outside of my experience. C245 tips use better technology for controlling the temperature of the iron, and it heats up much quicker than a ceramic core system.
Get a variable station rather than just an iron, those come with a wetsponge which is nice so you can clean the tip all the time which makes soldering much easier. You don't need to spend a lot of money on it, maybe 30 - 40 bucks tops.
As for solder, leaded melts much just at 150C, it's much easier to work with than lead free, and it's also cheaper. Get solder with resin core (not always stated)
I wouldn't worry about lead or flux poisoning at all if you're doing this casually, just don't breath the fumes directly and don't let them get into your eyes (it's nasty).
It may also be nice getting a desoldering plump, so you can undo and try again much easily, than trying to remove dirty or excess solder with the iron alone.
And finally, a soldering iron burn hurts a lot, and takes forever to heal so be careful with it.
My recs? Get a decent chinese soldering iron clone of expensive brands (e.g. a hakko clone) the number 1 thing that makes soldering not a pita is an iron that gets to specific temperatures fast and can inject a lot of heat rapidly. Double check the earth wire inside, cheap is good but QA/QC takes a hit.
If you want to do a lot of SMD soldering a proper station with hot air is nicer than repurposed stoves or drag soldering but a selection of tips and a little practice is worth it if you're just repairing random stuff.
Get lead free solder, all lead is hazardous and burdensome on the world and lead free solder is not difficult to use with a good iron. I can drag solder a stm32 with lead free and I am a noob.
Necessary consumables:
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rosin flux, soldering without flux is like washing dishes without soap. Flux cored solder is adequate in a pinch but a nice blob of rosin is so much smoother.
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solder wick. You will make mistakes or need to lift components, make it easier on yourself.
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solder (obvs) if you're fucking with ICs or smd components low temp is more comfy. Always use right temp and tip for your solder and task, hotter but faster is less heat than cold and slow generally.
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ipa to clean rosin
tips:
- tin shit first.
- redo bad connections, make sure you're wetting the part. Avoid raised beads.
- let parts cool between soldering
- work in a ventilated area
- tin the iron tip before storing. It keeps it from corroding.
- heat the lead not the solder. Solder won't wet a cold part.
What lead free solder would you recommend for basic thru hole work with a handful of DIP ICs?
Anything is fine really. Don't overthink it, just look at the temp it melts at. DIP you're way less likely to cook a chip anyway.
imho worrying about solder overmuch is like worrying about the specific type of nail in a carpentry project. Unless you're an expert or working at the edge of tolerances then it wont affect the final product much.
As credentials: I have handwired 2 keyboards and built an led cube. A good iron and rosin flux will do 90% of the work. Your only remaining job is to set the temp right, grow 3 arms to align stuff, and briefly touch the iron to pin.
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