When I made my very first solder joints (probably 6 or more years ago), I used a leaded solder that was just laying around, but there was only a little bit left so I soon ran out. Naturally, I went to Home Depot and bought some more solder, some flux, and a brass wool cleaner. I also bought a new soldering iron for unrelated reasons, which came with a small roll of leaded solder that I ended up keeping but didn't actually use until now.

The solder I bought (and kept buying) from Home Depot was the standard tin-silver-copper alloy lead-free solder, I believe SAC305. I remember thinking it was a bit harder to use than the 60/40 leaded solder I used to use, but it was a while ago and I don't really remember. Anyway, I just lost (yes, I am that messy) my partial roll of lead free solder, but I had to solder some things. I ended up resorting to using the solder that came with the soldering iron, which was of course leaded.

Holy crud! Leaded solder is just SO much easier to work with! It solidifies with a shiny finish (as opposed to that crusty white finish with lead free solder), it flows everywhere, I hardly need to use any flux at all because the flux core in the solder is enough to make it flow! I used a big box fan to blow away the fumes, but it was really great!

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To those of you who swear by using leaded solder, I definitely understand you now! I am probably going to buy a fairly large quantity of solder from amazon, and I would like your opinion:

Should I just keep buying SAC305? I am used to it, so it isn't like I am suffering. I solder really often, and I don't really like the idea of doing that with lead.

Should I make the switch to 60/40? It seems to perform much better but it is obviously poisonous.

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Thanks!

Don't buy it from a big box store. Proper brand name solder like Felder, Stannol, Multicore and such are much better, but are rarely sold at a big box store. I use Fuji-patented from i think Felder, with Sn/Cu/Ni/Ge. It is very close to being a drop in replacement to Sn/Pb solder, but it needs to run slightly hotter.
There is a single issue i'm running into and that is highly excessive tip wear. I have to figure out if it's a crappy batch of tips (new production Weller magnastat tips), i'll grab my cheap unregulated lead free suitable iron one of these days and check if the cheap iron has the issue too. If it is a solder problem, then it's specific to this brand and type of solder because it's not a common problem.
I haven't needed any additional flux at all.

You don't say anything about the new temperature you set your iron to. Soldering is not plug and play. Work at lead free temperatures with lead based solder, and you'll burn off your flux before getting the chance to solder.
Work at lead-based temperatures with lead free solder, and you'll have a crusty, hard to flow solder.

Soldering is not just plug and play. Every solder needs a different temperature.

I do still have a stash (about 1,5kg) of lead based solder, because i do a lot of repairs on vintage equipment. Mixing lead free and lead based solder is absolutely a cardinal sin. So if you are working in devices that are pre-RoHS, use lead based solder. The reverse is also true - don't use lead based solder in RoHS equipment. Even trace amounts of unplanned metals can really have a bad effect on your solder joints.

Keep a stash of Sn/Pb solder around for legacy equipment, but do keep working with proper name brand lead free solder, because the tin/lead stuff is getting harder and harder to get, and you better learn how to properly use the lead free stuff instead of relying on metallurgy that will only get more and more expensive.

I'm not too worried for the lead toxicity for myself (wash your hands with soap and water all the time!), the rosin is the most harmful part. However, how many people collect their little solder blobs and properly dispose of them at the chemical waste collection place of the municipality?
I know i haven't done that for the first 3 decades of my life... And that's a pretty shitty thing to do environment-wise.

@Laurens
I do plan on ceasing my business with Home Depot, very overpriced and questionable quality.

Tip wear is horrible with my current solder. I make my own iron tips with 1/4" copper tubing and other copper objects (mostly wire) filed into shape. Probably monthly I have to file down my tips and re-tin them because they become cup-shaped from wear. When I inevitably file the tip down to an unusably short length I will just make myself another one.

I set the iron to 350C, though I do not have much faith in the thermal accuracy of my cheap Chinese iron. I just adjusted it to melt solder reasonably quickly without boiling the flux instantly.

The likely reason I need so much flux is because of my soldering technique, which I do realize is unusual. I use a tip that is a little less than 1/4" diameter, put a big drop of solder on the tip, then use what is on the tip to solder. I often don't have the free hands (or coordination) to hold the iron in one hand and the solder in the other hand while holding the object to be soldered. This probably causes me to need more flux because of the time between melting solder and getting the solder to the joint.

I have repaired old equipment with lead-free solder, and I am just now realizing that might not be a great idea to mix solders like that. I also use a desoldering technique that may or may not get solder blobs everywhere. 

It is looking like I need to improve my setup!

Setup and technique and tips. Solid copper tips are a thing of the 1950s. Good enough for point to point wiring but they wear out really fast with any type of solder. Good irons have iron plated tips and have had that for decades. You should never sand or file those.
Copper tips have to be filed/sanded every couple of hours, that's normal procedure.

Here is a good video from Tektronix about how to properly solder: https://www.youtube.com/watch?v=yZSveVpgmIM
Anything temperature related is invalid for modern lead free solder.
Tektronix coincidentally used lead free solder for their special ceramic solder strips in their oscilloscopes, because the lead could interfere with the bond between the actual metal lug and the ceramic. My Tek 454a contains a tiny roll of that solder to ensure repair people don't use lead based solder on those solder strips, because back in the day no one had lead free solder on hand.

For your personal projects you of course do not have to satisfy RoHS requirements, so you can use whatever solder you want.

60/40 and 63/37 eutectic solders are easier to work, and give better looking solder joints. There is no problem with lead solder toxicity. Lead does not evaporate at soldering temperature. May be you should be a bit careful with fine powdered solder like when you are emptying desoldering pump, but just wash your hands afterwards. And that's all, no need to worry.


Lead / lead free incompatibility is significantly overhyped. Yes you can remove old lead-free solder with a wick to get better looking shiny joints, but at hobby level, reliability is not significantly compromised even if you omit that step. For the naysayers, it is even professionally considered OK to mount BGA chips having lead-free balls with leaded soldering paste.

Tektronix coincidentally used lead free solder for their special ceramic solder strips in their oscilloscopes, because the lead could interfere with the bond between the actual metal lug and the ceramic. My Tek 454a contains a tiny roll of that solder to ensure repair people don't use lead based solder on those solder strips, because back in the day no one had lead free solder on hand.

Sorry, but you are not right here. The problem with ceramic strips is just the silver layer quickly dissolving in molten solder. A common solution to this is to use a solder already saturated with a bit of silver. Leaded or lead-free, does not matter. A quote from vintagetek.org : 


"Special silver-bearing solder is used to solder wires and components directly to the
notches in ceramic strips and has a composition of 60% tin, 37% lead, 3% silver. This silver-bearing solder should be used when soldering or repairing ceramic strips which prevents the silver bonded to the ceramic from dissolving in the molten solder. Failure to use the correct silver-bearing solder on Tektronix ceramic strips can result in failure of the silver to ceramic bond.  Tektronix would include a small spool of silver-bearing solder for repair in some of its instruments."

https://vintagetek.org/ceramic-strips/

Oh yeah, you're correct, i got confused with other types of solder with regards to the ceramic soldering strips.