where to find unleaded solder without any of the downsides

[testtube44]

what kinds of solder is there out there?

what kinds of solder doesnt contain lead and doesnt have problems that some attribute to lead-free solder such as (formation of tin whiskers, higher melting point, pain in the ass to work with, etc)

[ataradov]

Are you working on space missions with 20+ year life span? If no, then literally any commonly lead-free solder will work just fine.

[Solder_Junkie]

Most home users stick with 60/40 tin/lead solder. Forget the “lead free” hype, 60/40 is widely available and is easier to use and makes better joints.

If you feel that you really need/want lead free, buy Weller, Kester, Multicore from a proper supplier, such as Mouser. Don’t buy junk from eBay.

SJ

[jonpaul]

The LF solder has a different physical property for melt/plastic/liquid temp, much higher then leaded esp than Eutectic 63/37

All the LF are costly and have downsides.

Required ONLKY in production to satisy idiot gov regs in US/EU, UK.

For DIY/home/hobby 63/37 leaded or 60/40 is fine.

Been leaded soldering since 1950s, am still alive!

Jon

[wraper]

SN100C is pretty much free of most of lead-free downsides except melting temperature. However flux quality is important in any solder, alloy is not the only thing that matters.

[MarkT]

You need the kind with 4% silver for hand soldering - there is cheaper stuff without silver, its not eutectic and horrible to use.  I think its Sn 95%, Ag 4%, Cu <1%

There may be formulations addressing issues like whisker formation - check out the ranges available from the big manufacturers of solder I guess.

[wraper]

You need the kind with 4% silver for hand soldering - there is cheaper stuff without silver, its not eutectic and horrible to use.  I think its Sn 95%, Ag 4%, Cu <1%

SAC305 actually isn't that good for hand soldering and also wears out soldering iron tips faster than silver free alloys.

[MarkT]

SAC305 actually isn't that good for hand soldering and also wears out soldering iron tips faster than silver free alloys.

Not my experience at all, no bit erosion after 10 years using it - that's usually caused by scratching the iron plating on the tip, not the type of solder - once the iron coating is breached a tip will rapidly get eaten (use a cellulose sponge not a brass one for long tip life).  You have to set the iron temperature a bit hotter and be careful never to leave it hot for more than a few minutes without re-tinning or it will oxidize due to the higher temperature.  The higher temps make it a little slower to make joints, say 2.5s rather than 1.5s (yes, you do have to adapt your technique a bit), and I think you have to be more scrupulous about cleaning copper parts that have an oxide build-up from storage - old wire often needs dipping in flux to get it to wet.

And for lead-free solder paste the noclean ChipQuik stuff I use works really well (SMD291SNL10, 96.5/3.0/0.5 Sn/Ag/Cu).

[Buriedcode]

The only problems I had with LF was well over a decade ago.  Standard SAC305 works fine, looks good, easy to use and I've been using the same LF tips with it for a good 6 years and they're still going.

Almost all of the complaints fellow engineers I know have had were based on a bad experience they had <2008, or they're using the cheapest, worst lead free solder they can find (99% tin, <1% flux etc..).  They then compare this to multicore leaded solder with extra flux.

Yes, leaded is easier to work with in that its very forgiving (you can use the wrong temp, bad technique, over heat joints and it'll still "work"), but over the years the differences have reduced to the point where I don't really care.  I only use leaded for repairs or rework. For work, obviously, its all LF.

[tooki]

SAC305 is old technology, so to speak: it doesn’t flow that great, and the silver makes it expensive.

Hands-down the best lead-free solder I have used is from Felder, with the SN100Ni+ alloy, which is the one with a bit of copper and trace amounts of nickel and germanium. The last two are critical, and are what make it different from the regular Sn99Cu0.7 alloys. The nickel and germanium make it wet nicely and produce shiny joints. Felder’s flux core works well, too, so the end result is a solder that is almost as nice to use as leaded. Yes, it needs a higher temperature (227C), but it’s eutectic and flows nicely.

I was recently talking to someone in a different department about lead-free, and after I mentioned that I really like this particular one, I gave him a few meters of it to try out. He emailed me a few days later and told me he was really impressed by it.

The same alloy is sold under various names by different manufacturers, all by licensing the patented formula from Fuji.

[tooki]

You need the kind with 4% silver for hand soldering - there is cheaper stuff without silver, its not eutectic and horrible to use.  I think its Sn 95%, Ag 4%, Cu <1%

There may be formulations addressing issues like whisker formation - check out the ranges available from the big manufacturers of solder I guess.

Yeah, no. You definitely don’t “need” silver-bearing, and IMHO it’s actually inferior.

It bears repeating that only 100% pure tin is susceptible to whiskers — it takes very little of other metals to frustrate whisker formation. Any lead-free solder is going to contain enough other metals to not worry about this b

[wraper]

The same alloy is sold under various names by different manufacturers, all by licensing the patented formula from Fuji.

SN100Ni+ has the same composition as SN100C. Dunno about relation between Fuji and Nihon Superior (SN100C) but the patents of latter had expired a few years ago and anyone is free to produce its clones without a license (NT100Ge for example https://nathantrotter.com/wp-content/uploads/2021/05/NT100Ge-Solder-Bar-and-Wire-Data-Sheet.pdf).

*This solder alloy was previously subject to a patent (US6180055) that expired in March 2019.  Nihon Superior Sha Co., Ltd. holds a separate patent for a solder joint
(US8999519B2) with a distinct chemical composition, consisting of, among other things, either exactly .01% by weight Cu or 7.6% by weight Cu.  NT100Ge has a certified
copper content of .5-.7% which lies significantly outside the solder joint patent criteria. If there are concerns about the full scope of the US8999519B2 patent or solder joint
composition, please consult an attorney. Nathan Trotter & Co., Inc. does not possess or confer to customers any intellectual property rights relating to the composition of
their solder joints or the name SN100C®, which is a registered trademark of Nihon Superior Sha Co., Ltd.

https://aimsolder.com/products/solder-alloys/sn100c

Nihon Superior’s patent on SN100C has expired in most countries. Consequently, any solder manufacturer can produce an imitation of SN100C.

[wraper]

It bears repeating that only 100% pure tin is susceptible to whiskers — it takes very little of other metals to frustrate whisker formation. Any lead-free solder is going to contain enough other metals to not worry about this b

100% tin is susceptible to tin pest. Alloys with other metals are still susceptible to whiskers, some more than others. Mechanism is still not well understood, mechanical stress seems to be one of the reasons initiating their growth. AFAIK SnPb is still the most resilient in this regard.

[testtube44]

the cause for this entire post is me wanting to avoid lead if possible, because lead is a health hazard, working with it forces me to b secure in what it touches and what i come in contact with while working with it, its a pain in the ass.

if its unavoidable then its unavoidable, but seeing these posts gives me some hope it isnt unavoidable.

[mikeselectricstuff]

Metallic lead is minimally hazardous. Fumes from the more aggressive leadfree solder fluxes  can be worse.