Does solder matter?

[ctjetta]

I know, I know, why don't I just as well ask about the sonic benefits of different headshells?

But I get curious. I see all the different options when looking at solder offerings, More tin, more lead. Thick, thin, or thinner. With silver (sounds like it's something I should want) or without.

Now if ever there was a forum with a group of experienced technicians, it's this here Tube Forum. And we know who you are so don't be trying to hide.

The thing with solder, besides the potential sonic differences (I'm leaving that subject open for debate) there is the actual application that is an issue, melting temps, et al.

So I'm looking to be enlightened. Maybe there's not much to discuss. If that's the case, then I'll just go buy a pound of the cheapest 60/40 something or other and be done with it.

But is that really what you want to see me do?

 

[thorpej]

Lead-free solder is a huge PITA to work with. I don't particularly care about being RoHS-compliant with any of my stuff, so I just use Kester "44" Sn60Pb40 (very easy to work with). If you care about "sonic" improvements, then you should be focused on solder that's easy to use and makes a solid joint, not distilled serpent extract.

 

[ctjetta]

Lead-free solder is a huge PITA to work with. I don't particularly care about being RoHS-compliant with any of my stuff, so I just use Kester "44" Sn60Pb40 (very easy to work with). If you care about "sonic" improvements, then you should be focused on solder that's easy to use and makes a solid joint, not distilled serpent extract.

I gotta say I was only mildly enthused about solder until you mentioned "distilled serpent extract". I wish to hear more!

 

[gadget73]

I prefer the 63/37 because it goes from liquid to solid instantly. 60/40 works fine, but there is a brief semi-solid period where the joint can get nasty if something moves. Solder size has more to do with the size of the terminal you're working with. I generally use .062 or .031 for most things, but I have used thinner or thicker when doing very large or very small things. Kester 44 or Ersin Multicore are my usual picks, but really any rosin core solder will get it done. I've melted a lot of Radio Shack solder over the years.

 

[primosounds]

You should know, if you did not, that the military and NASA do not use lead free solder. That is because eventually lead free will breakdown and can lead to a bad connection. Also lead free solders have a higher melting point and thus harder to work with , which can also lead to bad solder joints. The hazards of lead are somewhat overstated. I have been using leaded solder for over 30 years now, and other than an occasional bout with remembering which driveway leads to my house, damn tract houses! And the annoyance of being the defacto "lead shield" at the Xray machine at the hospital, (although i get to charge them double when they use me) there are no problems.

 

[2N697]

I would only use the lead-free version if nothing else was available and I was desperate to make a repair. I think a lot of the younger people I have worked with believe they can't solder worth a crap because they have been trying to use the lead-free stuff exclusively; it's terrible. I do however, see a difference between "fresh" and old stock; when leaded has been sitting around for a lot of years it can be more difficult to get a good bond. I always use the 031 as mentioned by gadget73.

 

[toxcrusadr]

63/37 is aka eutectic solder, which means the exact formula of any two metals that has the lowest melting point of all possible combinations. So it melts at the lowest temp of any Sb/Pb solder. Gadget73 is spot on about the melting POINT of eutectic vs. the melting RANGE of other mixtures. There's not a ton of difference between eutectic (183C) and 60/40 (183-191C) but the eutectic has a sharper transition.

Basically as you go left or right from 183, that triangle that starts to form means there is a widening temp difference between fully liquid and fully solid.
https://fctsolder.com/eutectic-solder/

 

[ctjetta]

I've never been Pb phobic, so that is not an issue for me. I have also never even considered the option of lead-free solder; it sounds almost like an oxymoron.
I do appreciate learning of the 63/37 version. Though "eutectic" sounds no where near as cool as "distilled serpent extract".
Thanks for your replies!

 

[Catmanboo]

Solder is meant to cement the connection. You should have a positive mechanical connection prior to soldering. I've gone so far as to extract, draw out into a long, thin bead of the excess solder, & reuse it with flux during repairs /mods. Call me weird, but at least you're keeping it "original! Lead-free solder is for plumbing, nothing else!
But that's just me...

 

[knockbill]

Proper solder iron heat is important also,,, ya don't want the tip to stay on the joints too long... I tin the tip before each joint, just to make sure its clean and hot...

 

[Catmanboo]

What he said, heat transfer is key.

 

[dB happy]

Not really applicable to audio, but google "tin whisker". It's where microscopic whiskers of tin grow off solder joints where frequencies are measured in ghz. It's crippled a few satellites. Lead in solder minimizes that.

 

[ctjetta]

It's funny. I work at my local phone company in the central office. At one, time much of the connections made for phone service within in the office were on on solder lugs. Some still are but a smaller percentage.
A proper connection is a single wrap of wire with just enough solder to flow and seal the connection.
Back in the day, when people cared about such things you would be reminded that the best connection is that wire at the lug- solder is a poor conductor. So sometimes you would see a wire wrapped 2, 3, 4 times and a wad of solder would be there attempting to hold it all together. That's when you knew an outside tech had come in and couldn't be bothered to wait for an office tech.
For those that care about such things, it would make you cringe.

 

[ctjetta]

Not really applicable to audio, but google "tin whisker". It's where microscopic whiskers of tin grow off solder joints where frequencies are measured in ghz. It's crippled a few satellites. Lead in solder minimizes that.

Back to my central office milleau- An outside tech called me and said there was a trouble on a customer's service. After much, much head scratching s to what was wrong I could just see one of those "tin whiskers" as you call them, the tiniest little thread of solder that created a short between two pieces of equipment. Due to my carelessness, I have to admit. A drop of hot solder that managed to fall 6-7 feet and juuuust make a connection.

 

[Catmanboo]

When I was stationed at karamursel, turkey, a joint spy base with air force, navy army & Turkish military, our telephone mainframe was all wire-wrap &solder. At some point, acid-core solder found its way in there, probably all they could get thru normal supply channels at one time, we were at the end of the line. No end of recurring headaches there. I brought back a 25-pair block of it for a souvenir. You gotta use the right shiite, 60/40 rosin core or external flux.

 

[primosounds]

It's funny. I work at my local phone company in the central office. At one, time much of the connections made for phone service within in the office were on on solder lugs. Some still are but a smaller percentage.
A proper connection is a single wrap of wire with just enough solder to flow and seal the connection.
Back in the day, when people cared about such things you would be reminded that the best connection is that wire at the lug- solder is a poor conductor. So sometimes you would see a wire wrapped 2, 3, 4 times and a wad of solder would be there attempting to hold it all together. That's when you knew an outside tech had come in and couldn't be bothered to wait for an office tech.
For those that care about such things, it would make you cringe.

In mil spec type soldering there was a whole class taught on the proper way to do it. The wrapped wire did not overlap so that the inspector could examine the soldering.

 

[rogerh113]

Agree about the lead solder. Did a bit of mil-spec soldering work at a little local subcontractor in my youth. You can achieve some really stunning solder joints after some practice. Yes, good solder work can be visibly impressive. I gather that if you are using silver or silver plated wire, it is useful to get solder with a small silver content. Kester has some that I use (with lead, of course). Supposedly it limits silver leaching out of the wire surface - someone might have a more technically accurate description....

 

[bean_counter]

I still have a couple of spools of Radio Shack silver, has always given good service - except for a batch (early 2000's?) that wasn't quite right and was very difficult to work with. Anybody remember that? They must have left out the above mentioned distillate of serpent extract. After that experience, I don't want to even think about using lead free.

I bought a big spool of Cardas Quad I'll use when the Rat Shack spools are gone.

 

[Pio1980]

Tektronix would pack a small roll of their preferred silver bearing solder in each piece of gear, back when the tie strips were silver plated ceramic.

 

[Blue Shadow]

Eutectic solders are the thing. There is the cardas quad-eutectic (four components) that some like a lot. The 62/36/2 silver-bearing solder (2%) is also eutectic. All of these are easier to use because of that single melting/freezing point, different for the different types, though.

This is the interesting thing about that cardas solder. Why do they call it a eutectic solder yet list a range for the melting point? That isn't right, but maybe they don't have any science of materials guys looking at their ad copy or maybe their solder composition varies and it isn't really eutectic.

As to size, I have 5 different sizes in the drawer. The 0.015 because it was available cheap when I ran out of my regular and handy when doing very small work. 0.020 is the Radio Shack silver solder. The 0.031 is the standard. The 0.050 was another solder that was available and I got that because an AKer was selling partial rolls cheap and it was a rosin core and could have been a 63/37. I find I like it for many things, the larger circuit board work. Then there is the 0.062 which was again part of the AKer partial roll buy, great for when you need to fill some area with solder.

I have two solder nails as I call them and one sewing bobbin with solder from 1-pound rolls sitting on my solder station. There are the .015, .031 and the .050. This gives me a choice readily available at the work point. I grab the others as needed. The nail is just slotted to hold the starting end and then wrapped three times or so more evenly on the lower levels on the thinner solder.


Having different size solder is a luxury for some because it will take years to use up a pound of the lesser used solders. I was lucky when an aker needed to unload some of different sizes and I like having the choice.

My question is how much better is nice fresh solder compared to some that is a decade old? The only new solder I use is the RS silver solder and it is a joy to use. Melts very nicely and produces a nice shiny connection.