Solder for Clean PCBs

[warpie]

As far asI'm concerned you can still buy leaded solder as long as you don't use it on commercial scale.

 

[Khron]

When I was just starting out, I got some soldering gear from the local hobby shop. I picked up some generic 60/40 solder, but soon changed over to Stannol HS10, a random pick (mostly due to it being 0.5mm) from a daunting list of cryptic specifications at my chosen online vendor. After restocking on the only solder I had good experience with, I have now run out. As far as I understand, solders containg lead are now banned (?) from sale, at least in my country (Norway) and I guess EU or most of europe.
Anyhoo, all solders seem to be exchanged with Tin(Sn) dominant mixes, with the choice of a pinch of copper or nickel added.
I just got some more 60/40 from a brand called Cynel, however this instantly reminds me of the first 60/40 I used; higher melting point, much worse wetting and flow of solder, sticky nasty residue that is hard to clean off.

How are these lead free solders? Should one stock up on one's favorite leaded type while it's still "available" from less health-concerned markets? Any recommendations on something I'd get from say Reichelt would be appreciated, as they don't stock pb solder like US vendors still do?

I'm guessing this should be comparable to my old favourite (flux wise atleast):

HS10 Sn99Cu1

or this one, supposedly clearer residue (mind me I would rather have residue that is easily washable)

Crystal 511

TME still stocks leaded solder, for what it's worth:

https://www.tme.eu/no/en/katalog/so...0014&s_order=asc&limit=20&currency=EUR&page=1

 

[warpie]

This one is leaded, isn't it?

https://eu.mouser.com/ProductDetail...=sGAEpiMZZMtyU1cDF2RqUC0Wd6L90CWNWhXs9VOBE20=

 

[fragletrollet]

Yes, and it's an American vendor. You guys lag a bit behind on healthcare

Practically speaking I don't see much risk, but theoretically customs can (and might) not let a package containing forbidden, harmful materials through the mail, setting you back a nice roundtrip in regards to shipping, at the very least. Might even confiscate it... although I don't see much risk of that happening.

Still interested about hearing your experience with the lead-less alternatives tough, would seem it is the long-term solution...

 

[Whoops]

As far as I understand, solders containg lead are now banned (?) from sale, at least in my country (Norway) and I guess EU or most of europe.

Not really,
commercial electronic products being sold in the EU need to be ROHS compliant, so that means they can't use Leaded solder in the manufacturing of those products.
Although solder containing Lead is not banned for sale, it's used for repairs and maintenance, so you can buy 60/40 solder in any EU country, you can also buy it in Norway.

Norway:
https://www.elfadistrelec.no/en/solder-wire-rosin-1mm-100g-weller-consumer-el-60-40/p/30164376
https://webshop.elektronikk-service.no/produkt/loddetinn-08mm-22g/
https://www.hobbym.no/maling-verktoy/weller-wel54004599-loddetinn-el-6040-100-1007019.html
https://nettbutikk.wuerth.no/sveis-gass-og-lodding/lodding-og-sveising/elektro-loddetinn-nr-1
https://www.nmj.no/weller-wel54004599-loddetinn-el-6040-100-1007019.html

Germany:
https://www.banzaimusic.com/Solder-SN60-0-25-100g.html
Portugal:
https://www.servelec.pt/solda-1mm-60-40-250g-pksold250g1p

 

[Whoops]

How are these lead free solders?

They are pure crap. Avoid

More info here:

https://groupdiy.com/threads/lead-free-solder-sn-ag-cu.76315/

 

[Whoops]

Still interested about hearing your experience with the lead-less alternatives tough

Hard to get it uniformly liquid, has a pasty feeling, hard to solder, hard to desolder, great for cold solder joints

 

[fragletrollet]

thanks for the feedback. Time to try some 62/36/2 !

 

[FIX]

Always get "no-clean" solder, and get the largest internal diameter of flux you can find. If buying lead, solder normally, if buying lead free, put the solder between the lead and iron so it helps transfer the heat faster. Lead free is a lot hotter temp and many times is hard to re-heat if the joint it sinked to a ground plane or chassis, so make the first one sound...

 

[calaverasgrande]

Kester K100LD/275 user here.
Works perfectly. When there is some residue it's safe to leave on, but I clean off on dense PCBs with cleaner I got at Microcenter. Need to get around to getting whatever Kester just for peace of mind though.
Have to admit I kind of overreacted on the lead free stuff at first.
Read some article that made it sound like lead free was going to be the only way to do things by 2015 so I figured may as well get used to it.
Started on MG lead free. Terrible fumes, sticky residue. Don't use that brand! It actually made me physically sick after a few weeks. Ended up tossing the rest of that roll and bit the bullet on the Kester leadfree.
Much better wetting, less fumes etc.
It never quite gets as shiny as leaded solder, sure.
But that isn't an indicator of joint integrity. Different alloys will have different surface characteristics. My gramps the metallurgist could probably go on for hours about that.
More important, I've been building stuff with K100LD for about 6 years. None of it has failed from bad solder joints or flux residue.
Nope, all of them that failed were due to my poor application of electronic theory and practice.

 

[kato]

FWIW, I think cleaned PCBs look amateurish. It leaves me with the impression, "that person doesn't know what he's doing."

 

[Whoops]

FWIW, I think cleaned PCBs look amateurish. It leaves me with the impression, "that person doesn't know what he's doing."

Why is that?

Cleaned PCB's look pretty good to me, better than the looks of pcbs with flux residue all over the joints

 

[Whoops]

Started on MG lead free. Terrible fumes, sticky residue. Don't use that brand! It actually made me physically sick after a few weeks.

Mate that's really dangerous.
It's a subject that is not talked enough, the danger of the solder fumes, you should not breath that stuff.

I advise everyone to buy a solder fume smoke extractor, there's really expensive stuff but even a cheaper unit like this ones will be thousand times better than not having anything and extract the fumes into your lungs:

 

[calaverasgrande]

Mate that's really dangerous.
It's a subject that is not talked enough, the danger of the solder fumes, you should not breath that stuff.

I advise everyone to buy a solder fume smoke extractor, there's really expensive stuff but even a cheaper unit like this ones will be thousand times better than not having anything and extract the fumes into your lungs:

View attachment 82494

View attachment 82495

View attachment 82496

I have a fume extractor just like the one in the last pic. I think it's a ripoff of a Weller design?
Upgraded it with a higher CFM fan I happened to have in my parts bin.
Even with a fume extractor the fumes are really bad on MG brand solder.
In other words, with windows open and a fan sucking the fumes away from me. The diffuse toxicity from the fumes affected me. I did some research on the byproducts of MG lead free. They had some kind of nasty stuff for flux that is closer to plastic than rosin. The byproducts when heated, according to their own MSDS, are non trivial amounts of acetaldehyde and other VOCs.
On a hunch I looked up how to eliminate VOCs from your system. (found a lot of info on bodybuilding forums, what is up with bodybuilders and VOCs?). That helped me turn the corner on that.
Still, MG solder not only spewed out toxic VOCs, it has terrible wetting and always had really crummy looking joints.

 

[Script]

There are many solder tests on YouTube. This just one.

Testing many kinds in closeup video for flow behaviour, flux amount and spill, as well as hotgun flow.

Quite interesting I found cos some more expensive ones seem not necessarily the best or that much better.

 

[HP200CD]

I vote for Kester 44 eutectic Sn 63% Pb 37%
Been using it for many years. Never had a cold solder joint failure.
Yes, it is hard to clean off the flux residue, but the flux is very effective.
Take your boards outside to clean them, use a VOC, and scrub with a brush, old school.

 

[Matador]

What exact chemical is approved to remove 44 flux residue? The datasheeet for Kester 44 describes a "saponifier" but doesn't recommend any particular one.

I have been using acetone and it seems to work well, however it's a crap shoot as to whether or not it will damage the silkscreen.

 

[john12ax7]

Kester K100LD/275 user here.
Works perfectly.

Have you compared the K100LD to any of the other 275 solders? I've been using the silver version, but curious how the Cu versions compare.

 

[warpie]

The one I posted earlier is supposed to be "no-clean'. Do you really have to remove the flux with such solder?

From the datasheet:

Cleaning 44 possesses excellent fluxing ability; the flux residues are non-corrosive, non-conductive and do not require removal for most applications under normal conditions of use. IPA will not clean the residues off the surface of the circuit board after the soldering process. If removal is required, a saponifier or cleaning agent specifically designed to clean a no-clean flux is required to clean the residues. Please contact Kester Technical Support for further information.

 

[Matador]

I don't like to leave it around high impedance nodes (250M or higher), because I doubt it's as 'non-conductive' as soldermask when dealing with nodes separated by less than 1 cm.