its about twice as expensive, but will make your life easier as you don't need to apply as much heat. So you'll save in fried delicate components.
For soft solder, the eutectic is SnAg3.5Cu0.9, which melts at 217C, 34C higher than the 63/37 eutectic Sn/Pb. There's a lot of low cost lead-free solder out there which is essentially pure tin[0], with silver and copper content below 0.5 percent each. That melts even higher, at about 230C, and tends to be not eutectic, i.e. it has a pasty range.
I think you are talking about the eutectic alloys with about 3% silver. Good stuff, but the higher temperatures involved make it harder to use without damaging the components.
For repairing 20th century electronics and for general DIY electronics use, 63/37 is great, and flows better than 60/40 - just wash your hands afterwards.
For repairing 21st century electronics, use lead-free for compatibility.
https://en.wikipedia.org/wiki/Tin-silver-copper
Also, to many people, saying "silver solder" means a silver-copper high temperature brazing alloy, which is a whole different thing. Better to say "tin-silver solder" or "tin-silver".
Edit: See also this entry on degradation of pure tin electronic connections[0]
[0] https://en.wikipedia.org/wiki/Tin_pest#Modern_tin_pest_since...
The tin solder you mentioned is 99% tin and has a very high melting point, so you'll have to be careful with hand soldering not to cause heat damage. You can also expect rework to be difficult, with lots of burned flux.
The photos at your link show some gorgeous joints, so good luck! It may be that the trace amounts of Ge in the solder will help with joint longevity.
Since I don't do production soldering, and cost isn't really a consideration for me, I use 3% silver alloy to keep the temperatures down, when I'm not using 63/37.
Kester solder listing:
https://www.kester.com/knowledge-base/lead-free-solutions#47...
Decent soldering station + correct and well taken care of soldering tip + thin multicore 60/40 + tools and supplies to clean your board + a bit of soldering training. There is lots of really good instructional videos on YouTube which is how I learned to solder.
It really depends on what you are building. If you're building a HAM transmitter then it is very useful.
The main use cases are certain alloy joints. I’ve seen it quoted as having better mechanical strength but that’s not what’s solder is for!
That depends. Back in the day when I did this work large end stages were built pretty much 'in the air' and in the stuff I worked on there were trimmers and coils that were pretty heavy and that were only supported by the solder. So we used silver for those joints, and they held up pretty good.
Hefty => 1KW and up...
As for the skin effect, that is the reason we did it in the first place, but I never had access to the kind of gear that would have allowed me to test in practice what the difference was and I've long ago stopped doing this sort of thing.
Skin effect makes sense. Hence why I use silver plated stuff in my VHF stuff.
Where do you buy this stuff? I’ve looked everywhere and I can’t find it. Amazon doesn’t have it, Mouser doesn’t have it, Digikey doesn’t have it. Seems like it might be discontinued!
https://www.digikey.com/en/products/detail/kester-solder/24-...
https://www.newark.com/w/c/tools-production-supplies/solderi...
Also, Amazon appears to have it, per this listing:
https://www.amazon.com/MULTICORE-LOCTITE-3096525-M-SOLDER-WI...
Looks like you can get it from Digikey as well:
https://www.digikey.com/en/products/detail/multicore/386824/...
Note that part of the problem might be if you're searching for "Loctite Multicore" and not just "Multicore". I think the brand might have been sold off, or something of that ilk, so you may not see it with the "Loctite" branding everywhere. I don't know the backstory on that entirely, but it's something I've noticed (being a big fan of Multicore solder!)
And since this whole sub-thread started with a mention of "silver bearing" solder IIRC, I'll point out that there are a couple of decent options there. I actually like the Radio Shack brand silver-bearing solder, but I don't know if it's still available or not. But Chip Quik have a product in that space[2] and they are a pretty reputable brand so I would expect it to be fine. That said, I don't think the whole "silver bearing" thing is terribly important and I rarely use the stuff myself these days. YMMV.
[1]: https://www.aliexpress.com/i/2251832830340296.html?gatewayAd...
[2]: https://www.amazon.com/Solder-Wire-Lead-Silver-no-clean/dp/B...
I also can’t emphasize enough just how much of a difference an application flux makes. I spent years struggling with sloppy solder work and thinking I was just doomed to be bad at it. Using flux made a massive difference. I was no longer having to constantly clean up bad joints or deal with solder blobbing where I didn’t want it. Just recently I was able to effortlessly hand-solder a bunch of tiny SMD components onto a board. Something I never thought I’d be able to do.
When I was learning to solder I really wish the importance of flux use was taught to me. It would have saved me a lot of cursing and frustration.