Leaded Solder is Best
Why would you want to use that lead-free garbage unless you're doing larger scale manufacturing that has to sell to RoHS-requiring regions?
One of the benefits of living in the good ol' US-of-A is that you are
not forbidden from using leaded solder like our poor friends across the water in Europe. Hell, if I moved to Europe I'd definitely bring along some leaded solder
contraband because I wouldn't want to be stuck without it.
Oh sure, lead-free okay for electronic manufacturers. They can control every aspect of their soldering process -- just like how they can use 60/40 solder without much problem -- and can expect that their products will get tossed relatively quickly so long-term soldering defects aren't much an issue. For everyone else, however, the benefits of leaded solder are enormous: better melting, lower temperatures, a less brittle and more durable alloy, better connections to the metal parts, etc. Don't sweat the lead-in-the-environment stuff either: the industry standards are a good idea because of the volumes of products they produce, the cost of recycling for them, and the disposal rate of their product. For your stuff it doesn't matter and the small amount of solder used in your projects will probably rarely enter a landfill anyway.
So first go buy yourself some 37/63 lead/tin-blend solder. That particular ratio make the alloy eutectic, which means it goes directly from solid to liquid phases when melted/solidified, not some intermediate state that can ruin the solder joint. The eutectic property is the secret to good solder and not having to worry about cold joints or other problems.
Don't buy that cheapo 60/40 blend garbage. That's for manufacturers who can control all their temperature profiles, not someone using a soldering iron. There is
no good reason for you to buy that blend unless you have a special machine to do your soldering and you're using solder paste.
Soldering Irons
I've found that it doesn't even matter if they're temperature regulated. Really. Why? Because other than being able to melt the solder in the first place, it's more a matter of technique, not iron temperature, that makes the difference. You're not going to be frying your laser diodes because you had a super hot iron, but because you had to fuss around trying to solder it properly and left the iron on the joint way too long (or had to keep repairing it). In fact, you'd probably cause more damage with an underpowered iron than an overpowered one (like dull knives instead of sharp ones).
For the most part, I bought temperature-controlled irons because they
heated up a lot faster than the non-temperature controlled ones. I could also potentially adjust the temperature for other types of solders, or bigger tips or something else, but generally it made little difference.
Buy a decent brand (Hakko, Aoyue, Weller, Metcal, etc.) if you can, but
work on technique more than anything. The tools are only as useful as the craftsman.
Soldering Iron Tip Tips
Things is right about soldering tips. You shouldn't need to replace them frequently, or ever for that matter. The
secrets to keeping your tips good
forever (barring unpreventable events or other people abusing your tools) are to:
- Never let your soldering iron tip oxidize. That means that anytime you're not soldering for more than 30s to 1 minute you cover the tip of your soldering iron with a gob of solder. Also remember to lather that soldering iron tip up with solder when you first get it too. Think of it like seasoning a cast iron pan. You should also always put a gob of solder on your tip after you're done soldering and have shut off the power. When you need to use your soldering tip again, just wipe off your solder on your sponge or cleaning material and you're good to go!
The solder protects the tip from oxidization caused by the heat and the atmosphere, and the flux in the solder cleans the tip from any impurities or other materials. Solder is cheap. Tips are not.
Especially beware when you're using flux to make the solder flow: often it causes the solder to leave the tip of the soldering iron onto the target, with little left on the iron to protect it. Load it back up when you're done.
- Protect the tip from mechanical damage (scratches). Your soldering tip is plated with metal to help it hold solder, protect the underlying metal from oxidization, and facilitate heat conduction. The iron is only for heating, not prying or pushing stuff (there are other tools for that). When you try to, for example, wedge a wire out of a pin hole with your heated iron tip, you may scratch that nice surface. USE SOME PLIERS.
When you clean the tip of your soldering iron, use a wet sponge (ideally with distilled water so it doesn't contain impurities), or some soft material like those brass wires sold as tip cleaners. Don't use those "tip renewal materials" that can damage the plating.
Some people may also say "oh I just grind down the tip whenever it stops working" well that's because they've already ruined their soldering iron tip, and their soldering iron tip is pretty much a heated nail at that point. That's okay if you've got a piece-of-shit communal iron that you don't care about, but for your own stuff, treat it good!
