Solder quality

[Jamieson]

On a side note, how DO they get the strands of flux into solder wire?  It must be some sort of extrusion process, but seems like getting the amount of flux to be consistent would be tricky.

[nanofrog]

On a side note, how DO they get the strands of flux into solder wire?  It must be some sort of extrusion process, but seems like getting the amount of flux to be consistent would be tricky.

Think a pipe (extruded) that's filled with flux, then drawn over and over again to achieve the desired outer diameter (i.e. stretched to get a smaller diameter each pass). 

[aabbcc]

So there are so many suggestions I'm getting dizzy.

I'm looking on stocking up on a good solder, I'm mainly building synths with through hole parts.

* 60/40 (have only been using this) or maybe 63/37 since I've been hearing good things about this
* Low amount of spattering, currently using a roll of Stannol 60/40, 0.7mm, Kristall 400 and this spatters like crazy
* Preferably some kind of no-clean that does not leave a lot of residue behind (the stannol one aboves leaves alot, although its transparent)
* Available in Europe (mouser would be nice since I'm placing an order there soon)
* Thickness of 0.5-0.7mm
* I think I want halide free

I found the kester 245 on mouser (altough its very pricey...)
https://www.mouser.se/ProductDetail/Kester/24-6337-8800/?qs=%2fha2pyFadujnrjyvwJOvPegyNY9paaRDAht9AsrttEOz1HswD7f4gw%3d%3d

[nanofrog]

So there are so many suggestions I'm getting dizzy.

I'm looking on stocking up on a good solder, I'm mainly building synths with through hole parts.

* 60/40 (have only been using this) or maybe 63/37 since I've been hearing good things about this
* Low amount of spattering, currently using a roll of Stannol 60/40, 0.7mm, Kristall 400 and this spatters like crazy
* Preferably some kind of no-clean that does not leave a lot of residue behind (the stannol one aboves leaves alot, although its transparent)
* Available in Europe (mouser would be nice since I'm placing an order there soon)
* Thickness of 0.5-0.7mm
* I think I want halide free

I found the kester 245 on mouser (although its very pricey...)
https://www.mouser.se/ProductDetail/Kester/24-6337-8800/?qs=%2fha2pyFadujnrjyvwJOvPegyNY9paaRDAht9AsrttEOz1HswD7f4gw%3d%3d

Details:

• Alloy: 63/37 is eutectic, which means it will solidify at a single temperature. 60/40 doesn't, which means there's a plastic range (temp range before both metals solidify). Originally, 60/40 came into existence because lead is cheaper than tin. The difference however is negligible these days.
• Regarding spattering, the smaller diameters will splatter more as a general rule. But tier 2 brands and below are worse about it for a given diameter IME. It's just not worth the extra expense and aggravation than spending the money on quality supplies/consumables IME. As to why, it's harder to draw the solder + flux core down to smaller diameters without gaps/voids in the flux core.
• Remaining residue has to do with the amount of flux remaining after a joint is completed (assuming a properly executed joint). Which means the more flux in the wire by % weight, the more residue that'll remain. As per no-clean, some are rosin, modified rosin (semi-synthetic), or purely synthetic resin based. True rosin based are the easiest to clean, with purely synthetic resin types being the hardest IME.
• If you're ordering from Mouser, I'd recommend 24-6337-0027 (Kester 44, 63/37, .031", core 66/3.3% by weight) instead.
• As per halides, unless you've a specific requirement that these aren't an option, I wouldn't worry about it. They're more active than their non-halide equivalents, which means they do a better job at what they're designed to do. And FWIW, I find that halide containing fluxes are better for hobbyist users/small repair shop use IME (more forgiving in regard to a well executed joint).

[ThomasCee]

Yeah, just purchased some cheap overseas solder myself ($6.90USD for a .5mm, 2% flux 500g roll, pic below). Wow, terrible. The shop I worked for years ago provided the solder, and I never thought anything of it; I figured tin was tin and lead was lead. But this stuff was horrid, similar to ttt's pictures on the first page of this thread. Icy cold and crusty looking, and no way any way can you get it to shine.
So now I'm browsing Kester's line up, and now realizing how much I didn't know about the topic lol. Looks like for hand soldering I suspect I'll end up with Kester 44 for Rosin or 275 for No Clean in .6mm size (Just gotta decide which flux type I should go with).
But yes as the OP asked, solder quality makes an enormous difference as I recently learned first hand 

[netdudeuk]

Yeah, just purchased some cheap overseas solder myself ($6.90USD for a .5mm, 2% flux 500g roll, pic below). Wow, terrible. The shop I worked for years ago provided the solder, and I never thought anything of it; I figured tin was tin and lead was lead. But this stuff was horrid, similar to ttt's pictures on the first page of this thread. Icy cold and crusty looking, and no way any way can you get it to shine.
So now I'm browsing Kester's line up, and now realizing how much I didn't know about the topic lol. Looks like for hand soldering I suspect I'll end up with Kester 44 for Rosin or 275 for No Clean in .6mm size (Just gotta decide which flux type I should go with).
But yes as the OP asked, solder quality makes an enormous difference as I recently learned first hand 

I'm the OP and yes, there really is a big difference. My MG Chemicals spools are far better than the Chinese cheap brands.

[ThomasCee]

I was just blown away, I had no idea.

Forum etiquette question: is it okay to ask some more "best solder questions" in this thread? Or should I start a new?

Don't want to be that noob forum hijacker 

[cowasaki]

If you want the equivalent of 62.5/37.5 but with silver in it what ratio do we need to look for?   {62/36/2} ??

What diameter solder do most people prefer?   {1mm} ??

What temperature?   {179C} ??

Flux amount?   {1%} ??

I have a real of solder that is so fine it causes me problems.  My favourite solder was a 500g real that so probably down to 50g left but the maker's sticker and info have long gone so I've no way of finding out what it actually was!

I've looked on CPC's web site (they are literally just down the road) but there are so many I just usually end up taking pot luck.

[mariush]

See https://en.wikipedia.org/wiki/Solder#Solder_alloys


Sn62Pb36Ag2 is euctetic like Sn63Pb37 and its melting point is 179c.  There's also the 1% Copper variety, Sn62Pb37Cu1 (was used to reduce iron tip wear, not so much anymore)  with melting point 183c like regular 63/37.

I'd go with 2% flux or more, anything but water soluble, preferrable no-clean or RMA.

I'd go with less than 0.7mm diameter, my current choice these days is 0.56mm - you can always cut a bit of solder and bend it two for thicker wire if needed, yet it's small enough to feed when soldering surface mounted components.

If you want something cheap and good and hassle free, you have regular 60/40 for 13 pounds , 0.71 mm , 250g, 2.2% flux, no clean required : http://cpc.farnell.com/multicore-solder/609961/solder-wire-crystal-400-0-71mm/dp/SD01822

CPC doesn't seem to stock the 63/37 and 62/36/xx varieties.

RS Components (UK company) has
* 30.5  pounds : 250g Stannol 62/36/2 0.5mm 2.5% rosin flux   : https://uk.rs-online.com/web/p/solders/0518012/
* 41.15 pounds : 500g Stannol 62/36/2  0.7mm 2.5% rosin flux https://uk.rs-online.com/web/p/solders/0517889/

TME.eu (Polish company) also stocks 1% no-clean flux of that Stannol

* 11.28  pounds : 250g Sn62Pb36Ag2; soldering wire; 1mm; 0.25kg; Flux: No Clean  https://www.tme.eu/en/details/s62a2hf32_1.0_0.25/solders-wires/stannol/640045/
* 12.50 pounds : 250g Sn62Pb36Ag2; soldering wire; 0.7mm; 0.25kg; Flux: No Clean  https://www.tme.eu/en/details/s62a2hf32_0.7_0.25/solders-wires/stannol/640044/
* 15 pounds : 250g Sn62Pb36Ag2; soldering wire; 0.5mm; 0.25kg; Flux: No Clean https://www.tme.eu/en/details/s62a2hf32_0.5_0.25/solders-wires/stannol/640049/


and you have a good deal here for regular 63/37

* 13 pounds for 500g  Sn63Pb37; soldering wire; 1mm; 0.5kg; Flux: F-SW26  (no-clean) : https://www.tme.eu/en/details/s63hs10_1.0_0.5/solders-wires/stannol/543068/
* 15 pounds for 500g Sn63Pb37; soldering wire; 0.7mm; 0.5kg; Flux: F-SW26 : https://www.tme.eu/en/details/s63hs10_0.7_0.5/solders-wires/stannol/543016/
* 21 pounds for 500g Sn63Pb37; soldering wire; 0.5mm; 0.5kg; Flux: F-SW26 : https://www.tme.eu/en/details/s63hs10_0.5_0.5/solders-wires/stannol/543014/


edited : feet -> feed

[cowasaki]

CPC doesn't seem to stock the 63/37 and 62/36/xx varieties.

http://cpc.farnell.com/webapp/wcs/stores/servlet/Search?catalogId=15002&langId=69&storeId=10180&categoryId=700000008637&pageSize=25&beginIndex=1&showResults=true&pf=111750266

CPC's web site is terrible!

Thanks for all that.  I will take a look at the alternative companies you mentioned and it looks like 62/36/2 with 2%+ then.

[netdudeuk]

CPC doesn't seem to stock the 63/37 and 62/36/xx varieties.

http://cpc.farnell.com/webapp/wcs/stores/servlet/Search?catalogId=15002&langId=69&storeId=10180&categoryId=700000008637&pageSize=25&beginIndex=1&showResults=true&pf=111750266

CPC's web site is terrible!

Thanks for all that.  I will take a look at the alternative companies you mentioned and it looks like 62/36/2 with 2%+ then.

I like the MG Chemicals solder that  I got from here

http://www.circuitspecialists.eu/soldering/?cat=109

[tooki]

I also am happy with MG.

FWIW, their desoldering wick is the best I’ve tried, hands down.

[Bud]

In my experience and to my taste Kester has noticably better wetting than MG. Whenever possible i go for Kester.

[netdudeuk]

I also am happy with MG.

FWIW, their desoldering wick is the best I’ve tried, hands down.

Solder wick. Another thing that can be bought for next to nothing on eBay and be junk compared with a slightly more expensive alternative from Soderwick or the like.

[ThomasCee]

Cowasaki, if you had one of those cheap little calipers floating around your garage, it could be handy so you'd have a frame of reference... I had no idea what I had either, then purchased the cheap stuff which was no good, but I also in the process realized 0.5mm was a bit too small for me; would have been a bummer if I had bought a full pound. Turns out my original good solder was about 0.8mm. Will try 0.6 for the Kester stuff when I buy.

You can also cheat on your cheap wick; melt a little flux on it and its sucks solder like crazy 

[ThomasCee]

Bud: Do happen to know which Kester stuff you have?

I'm thinking of trying this one:
Kester 44; Sn62Pb36Ag02; #44; diameter 0.025"/0.60mm; Core 66; 3.3% flux; Contains Halogen; 1 LB Spool; Part # 2471500018; RA flux ( https://www.kester.com/products/product/44-flux-cored-wire ).
I am considering the #44 since I will be doing all hobby work, and like the idea of the active resin with really good flowing properties. I am considering the 2% silver content based on Macboy's report on post #42 how shiny the his joints were 

I'm leaning that way, but if I went for a "no-clean" flux, I was considering the Kester 275. Best I can tell, 245 is better for production, and 275 was better for hand work; but, is that true?
Kester's description seeeeeem to indicate that but I'm not sure.
Kester 245: https://www.kester.com/products/product/245-flux-cored-wire
Kester 275: https://www.kester.com/products/product/275-flux-cored-wire
Also this thread was interesting: https://www.eevblog.com/forum/reviews/kester-245-vs-kester-275-for-sn63pb37/
So if I went 275, I'd get: Kester 275; Sn63Pb37; #275; diameter 0.025"/0.60mm; Core 58; 2.2% flux; Contains Halogen; 1 LB Spool; Part #2463377617; No-Clean flux.
I'm sure it will flow well, buttttt...... Will it flow as well as the #44?

Thoughts?

[tooki]

I also am happy with MG.

FWIW, their desoldering wick is the best I’ve tried, hands down.

Solder wick. Another thing that can be bought for next to nothing on eBay and be junk compared with a slightly more expensive alternative from Soderwick or the like.

Absolutely! (And yes, the MG is IMHO way better than Soder-Wick, which itself is excellent!)

[nanofrog]

I'm thinking of trying this one:
Kester 44; Sn62Pb36Ag02; #44; diameter 0.025"/0.60mm; Core 66; 3.3% flux; Contains Halogen; 1 LB Spool; Part # 2471500018; RA flux ( https://www.kester.com/products/product/44-flux-cored-wire ).

Thoughts?

For hobbyist use, I'd recommend going with Kester 44 in 63/37 alloy, a diameter of .025" or .031", and core size of 66 (aka 3.3% by weight). This will keep you to a single roll of solder which is also more cost effective than multiples.

The reasoning behind this is that its RA flux core is good for both new and old boards & components. Also note that 63/37 is less expensive since it contains no silver.

Both alloys are eutectic and make shiny joints.

[ThomasCee]

K, that makes sense. The experimenting bug has bit me  That's what got me curious about the silver stuff.
I am finding alot of places in the states have 25 order minimums, or they are almost twice as expensive as the other places. Still browsing; I have some of my old "good" .031 63/37 left, so it's not critical yet; still price browsing.

[nanofrog]

K, that makes sense. The experimenting bug has bit me  That's what got me curious about the silver stuff.
I am finding alot of places in the states have 25 order minimums, or they are almost twice as expensive as the other places. Still browsing; I have some of my old "good" .031 63/37 left, so it's not critical yet; still price browsing.

The following sources might be of interest (US based warehouses):

• Mouser
• Digikey
• Newark
• All-Spec

This list isn't all-inclusive, but they sell single rolls (buying directly from Kester will involve Minimum Order Quantities).

[macboy]

I can think of absolutely no reason, besides cost, not to try the 62/36/2 alloy having 2% silver, vs a more typical but less expensive 63/37 or 60/40.

The 62/36/2 alloy is eutectic, and melts at lower temperature than even 63/37. Silver has the highest thermal and electrical conductivity of any metal, so this alloy has better conductivity as well. Joints will not only have a smooth shiny surface, but a bright "color" as well, giving them a beautiful mirror-like appearance, compared to the shiny but slightly grey appearance of 63/37. The addition of the silver improves mechanical strength and helps prevent surface oxidation of the solder wire, improving shelf life. (I have a couple rolls that are several years old and still mirror-shiny). If you solder to silver plated terminals (such as inside old Tek scope) then you must use silver-bearing solder to prevent errosion of the plating which destroys those terminals. The only negative I know of is cost, so if you can afford the one-time higher cost of the roll, then go for it.

You will not regret Kester 44 with size 66 (3.3%) core, no matter which alloy you go with.

[nanofrog]

FWIW, if cost wasn't a factor, I'd use 62/36/2 all day long. For disclosure, I've a few of the small spools from RadioShack that get used primarily when stronger mechanical bonding is required.

Unfortunately, the current prices will make you cringe:

• Kester 24-6337-0018 ($52.90 per 1lb spool)
• Kester 24-7150-0018 ($110.18 per 1lb spool).

Don't know about anyone else, but $100+ for a single roll of solder is too much for hobbyists IMHO. Better to find 62/36/2 in a smaller roll.

As per temps, it's not that different at all. 62/36/2 melts at 179C, while 63/37 melts at 183C. So a whopping 4C difference. 

[lmaokore]

FWIW, if cost wasn't a factor, I'd use 62/36/2 all day long. For disclosure, I've a few of the small spools from RadioShack that get used primarily when stronger mechanical bonding is required.

Unfortunately, the current prices will make you cringe:

• Kester 24-6337-0018 ($52.90 per 1lb spool)
• Kester 24-7150-0018 ($110.18 per 1lb spool).

Don't know about anyone else, but $100+ for a single roll of solder is too much for hobbyists IMHO. Better to find 62/36/2 in a smaller roll.

As per temps, it's not that different at all. 62/36/2 melts at 179C, while 63/37 melts at 183C. So a whopping 4C difference. 

There are some 1lb spools of 0.5mm Alpha Metals Sn62 for about $35 on Ebay. Not too much more expensive than 63/37.

62/36/2 looks absolutely beautiful compared to 63/37.

[nanofrog]

FWIW, if cost wasn't a factor, I'd use 62/36/2 all day long. For disclosure, I've a few of the small spools from RadioShack that get used primarily when stronger mechanical bonding is required.

Unfortunately, the current prices will make you cringe:

• Kester 24-6337-0018 ($52.90 per 1lb spool)
• Kester 24-7150-0018 ($110.18 per 1lb spool).

Don't know about anyone else, but $100+ for a single roll of solder is too much for hobbyists IMHO. Better to find 62/36/2 in a smaller roll.

As per temps, it's not that different at all. 62/36/2 melts at 179C, while 63/37 melts at 183C. So a whopping 4C difference. 

There are some 1lb spools of 0.5mm Alpha Metals Sn62 for about $35 on Ebay. Not too much more expensive than 63/37.

62/36/2 looks absolutely beautiful compared to 63/37.

At that price, it would be worth it.

But for fresh solder, the silver bearing alloys are quite a bit more expensive these days. 

For small tubes, it's possible to get 62/36/2 in Kester 44, .025" in a small solder pak (Kester 83-7145-0415). It's under $5 shipped, so there's no need to skip out on it altogether. 

[tooki]

FWIW, if cost wasn't a factor, I'd use 62/36/2 all day long. For disclosure, I've a few of the small spools from RadioShack that get used primarily when stronger mechanical bonding is required.

Unfortunately, the current prices will make you cringe:

• Kester 24-6337-0018 ($52.90 per 1lb spool)
• Kester 24-7150-0018 ($110.18 per 1lb spool).

Don't know about anyone else, but $100+ for a single roll of solder is too much for hobbyists IMHO. Better to find 62/36/2 in a smaller roll.

As per temps, it's not that different at all. 62/36/2 melts at 179C, while 63/37 melts at 183C. So a whopping 4C difference. 

That said, realistically, even at $110/lb, it's not that bad! I mean, how much solder do you really use? A pound of solder lasts for thousands and thousands of joints, the cost per joint is negligible.

It's one of those things, to me, like dish soap and laundry detergent: even if I buy the "expensive" stuff, it's still negligibly cheap in the grand scheme of things...