I am still using solder from a reel i bought when i was a teen way back in early 80s which is a Rosin cored 60/40 and i love to smell the fumes when i solder, maybe if i was using a modern day solder it wouldn't smell so good and i'd just hold my breath while making the joint but like i have said, many of us home hobbyists don't solder for long enough at a time for the fumes to be a health hazard.

 

If you need to guess what's in your solid, it's not a quality product. AliExpress, Temu and similar sites are NOT a good place to buy solder. One roll I got from one of these sources would be ok for a few centimeters, then it wouldn't even melt even when I cranked my iron temperature way up. Cut a length off and there might be another sweet spot but the joy only lasted a few seconds before hitting another bad section. It's hard to imagine how this happens – the alloy had to be inconsistent.



Solder from a quality source will document exactly what's in the solder. If the type of flux isn't clearly identified, don't buy it.



And a word to the wise: If you use tin/lead solder, use 63/37 rather than 60/40. 63/37 is eutectic solder – it goes from liquid to solid without a plastic phase (this is pure physics and not open to debate). When soldering a wire to connector for example, and your fingers are getting warm holding the wire, the solder will instantly switch from liquid to solid. No risk of a cold solder joint from jiggling in the plastic phase. See the diagram below.

 

If they use a filter, it's usually an activated charcoal type.

But, as I said earlier, unless you're soldering for many hours at a stretch, mask and extractor are unnecessary. Just hold your breath while you're actually soldering.

Noted!

 

I am still using solder from a reel i bought when i was a teen way back in early 80s which is a Rosin cored

That is what I will try to find on flea markets now.

 

So far I worked from an old big pile of soldering wire, that my father purchased long ago. It had a classic rosin smell when melted, that I could always smell when working with soldering wires. But I run out of the pile, and first I tried to buy something on Aliexpress. When it arrived and I tried it, I was satisfied to see that it melted more easily than my old pile, but it emitted very very bad smell. It had a smell like gummed paper tape, that is used by artists to fasten paper onto boards. Then, I tried to buy something at the local electronics shop, where the quality is not outstanding but usually OK. Tried the wire purchased there: the same bad smell. Now I wonder where I could buy the wire that has a similar rosin smell like my old pile. Any idea from Aliexpress? If not, from a store in the US or Germany?

The difference you’re noticing comes from the flux, not the metal in the solder. Your old wire likely used traditional rosin (colophony) flux, which gives that classic pine-like smell, while many newer or cheaper wires use no-clean or synthetic flux, which can smell harsh or like glue/tape when heated. If you want the same experience again, look specifically for solder labeled “rosin core” (RA or RMA) and avoid anything marked “no-clean.” Reliable brands that still offer this include Kester, MG Chemicals, and Stannol.

 

And a word to the wise: If you use tin/lead solder...

For the record, there are eutectic alloys among the lead-free options as well.

 

...this include Kester, MG Chemicals, and Stannol.

You suggest avoiding anything that says "no-clean" but the link you provide on Kester is to an industrial sized drum of liquid no-clean flux. Why?

Additionally, lest anyone be confused by your comments, I assume they are indeed for the case of wanting to snort colophony particulates and not general advice about soldering flux. Modern, no-clean fluxes are amazingly good and... don't require cleaning (though I don't know any hobbyists happy to leave powdery white residue on her PCB).

 

If you want the same experience again, look specifically for solder labeled “rosin core”

On the market of solders this is not a working strategy here where I am, sadly. I have purchased a tube of such solder some days ago, the smell is kinda okay, but definately not the true rosin smell. Still smells as if something was burning, but it is not as intense as in case of the solder from Aliexpress. Bearable. But it is possible that some of what is sold with the note: "rosin core" might be true. I have just not found it yet locally. But from my area I got similar responses recently. It might be surprising for me because I have used old solders scattered all around our house by my father, so I did not try anything up to date in the last 10-15 years.

 

I have used old solders scattered all around our house by my father, so I did not try anything up to date in the last 10-15 years.

All of my rosin cored solder is from the 1970's and 1980's. All of my recent purchases have been noclean. I bought a many lifetimes supply of Alphametals 63/37 Cleanline 7000 in 4 diameters 15-20 years ago (from an Ebay seller who sold liquidated company stock).

 

Alphametals is good stuff, I have a couple of spools of very fine 62Sn/36Pb/2Ag and one of a eutectic RoHS alloy.

 

If you wanted to make your own liquid flux, iirc, you can just purchase pine rosin (or resin) flakes, or a block of pine rosin for violins (more expensive per gram), then dissolve them in some grain alcohol (denatured or "pure"). Then put the liquid in a container to squeeze it out.

However, what you'll end up with is likely more flux than you could ever use, and it won't be cheaper (and maybe more expensive) to make.

So if you can find some regular pine rosin/resin liquid flux from a good company - even just a little will go a long way.

Using it (or flux paste) though likely is challenging; you'd have to put it down on the points you are soldering, then use your iron and non-flux solder. Seems like it would be awkward at best.

Now - if you are doing SMT work - liquid and paste flux (and especially, paste solder - which is like paste flux mixed with powdered solder) - that's where it can shine; like, you can put the paste solder down, plop the part in place, then use hot-air to reflow (or use a chisel/wedge tip for drag soldering) - and it's like "magic" how the parts and such just self-align and the solder "pools" or "wicks" right where it should be.

Something else I've found is that if you are working with something that used non-leaded solder, and are having problems with getting it up to temperature, or staying hot enough for removal or something - add in some leaded solder to the joint, and you'll be able to work with it easier (it lowers the temps for flow, for one thing). Note that this would only be for hobby applications and rework, not production stuff.

 

If you wanted to make your own liquid flux, iirc, you can just purchase pine rosin (or resin) flakes, or a block of pine rosin for violins (more expensive per gram), then dissolve them in some grain alcohol (denatured or "pure"). Then put the liquid in a container to squeeze it out.

However, what you'll end up with is likely more flux than you could ever use, and it won't be cheaper (and maybe more expensive) to make.

So if you can find some regular pine rosin/resin liquid flux from a good company - even just a little will go a long way.

Using it (or flux paste) though likely is challenging; you'd have to put it down on the points you are soldering, then use your iron and non-flux solder. Seems like it would be awkward at best.

Well, making my own is just a plan B, but in case I cannot buy a larger bulk of the old style of wires, it might happen. However, here where I live, it is not challenging for the rosin price. Distilled pure rosin is cheap where I live, would cost the same as a can of paste flux. I can also put the solution into such a bottle you can see here. Exactly the same like the liquid flux I am using now in a bottle, that I purchased from a shop locally:

So as far as application is of a concern, nothing would change compared to how I apply flux now.

Why the whole thing would be a problem for me is more to the unavailability of the solid core solder here. I cannot find thinner than 2mm wires. But as I wrote it is really just a plan B.

 

My soulmate: