Soldering 63/37 solder

[alparent]

I got some 63/37 solder from ebay.
But this thing is a pain to solder. Got to crank up the iron to 400. Feels more like lead-free stuff. The stuff doest flow at all.

Any tips on soldering 63/37? Or is it just that ebay stuff is crap. It also feels cruddy!? As soon as I take away the iron it goes solid and flat gray?
How should 63/37 feel? Is is flat or shinny when it hardens?

I've always used 60/40 before and I'm pretty good at soldering. But with this new solder my boards look like they where soldered by a 2 year old with parkinson's!

[bean]

I use 63/37 Kester a lot and that's pretty typical. At first I worried that I was getting cold joints or maybe my technique just suddenly started to suck, but it seems that it just goes a bit gray/flat on its own. I have my iron cranked up, too.

[defaced]

Is is flat or shinny when it hardens?

Shiny, in so far as there is still rosin (flux) remaining to protect the molten solder during solidification and the materials are clean.  The composition of the solder (60/40, 63/37, lead free, etc) is only one component of what makes a good shiny solder joint, the other is the rosin.  Considering you bought your solder from eBay, it may just be improperly labeled or of poor quality.  63/37 is just the nominal composition, it doesn't say anything about what other junk is actually in the solder which could mess up its melt characteristics.  Or is may have precious little rosin in it, or poor quality rosin.  If you have access to supplemental rosin, I'd evaluate soldering with it and this new wire.  That will help isolate the issue to either a rosin issue or a metal issue.  When molten metal is involved, cleanliness is next to godliness, and godliness is next to impossible.  Cleanliness extends beyond the surface and also into the elements in the material itself.  

I use 0.032" Kester 44 and 245 (no-clean) flux with good results on a regular basis.  

Edit:  You mentioned the solder feeling gnarly.  That's probably a sign of crud on the surface of the solder.  Since solder is a low temperature process, that crud is just going to float to the top of your solder joint and make it look bad all the while impeding heat transfer.  So while you're playing with flux additions, take a length of your solder can abrasively clean it.  Something like a scratch pad, brillo pad, wire wool, or even fine grid sand paper will work.  Once the solder looks shiny and feels smooth, clean it with (at a minimum) water just to rinse off the debris, or best would be a wipe of acetone then a wipe with alcohol.  Then solder with it. 

[Kesh]

Strange, 63/37 has a lower melting point, the lowest possible with tin/lead solder.

Maybe your solder's flux is no good.

I use both and don't notice much difference.

[Arcane Analog]

I always make sure to clean the traces/vero/etc with fine sandpaper and then clean them with acetone right before soldering to make sure there is nothing to gum up the joint. Just as important as cleaning your iron tips in my opinion.

[R O Tiree]

63/37 is a eutectic mix, it sez 'ere, which means the crystalline matrix "fits" together nicely and it all happens at one specific temerature which is, as Kesh said, the lowest possible for these 2 metals.  60/40 is almost as good, but cheaper to produce.

Call me an old cynic, but do you think it might have crossed some little toe-rag's mind that hobbyists still want 63/37 solder and can charge a premium for it... why not say it's 63/37 but flog some inferior Pb-free sh!te instead.  Who's got the wherewithall to test it?  Who do we complain to if it isn't the right stuff? 

[R.G.]

I like RO's idea. I've used real Kester rosin core eutectic before. It's identical to 60-40 except that (1) it melts slightly earlier than 60-40, as you'd expect, and (2) it BANGS between solid and liquid and vice-versa. There is no perceptible time between solid and liquid where it's soft. It's unsettling if you're used to watching the solder go through a soft stage in a joint.

I suspect someone decided to sell the junk for premium.

Actually, we all have the wherewithall to test for it. The melting temp tells the story.

Eutectic melts before any other tin-lead alloy, and also before any of the commercial lead-frees, although there are some tri- and qui-nary compounds with bismuth that can get lower.  Put a dab of the unknown on a heating surface with some knowns, for instance some 60-40. If it does not melt before the 60-40, and does not "flash" between solid and liquid, you may not know exactly what's in it, but you know for certain that it's not 63/37. 

I performed this test on some house plumbing joints once to demonstrate how I'd win the case if I had to sue the plumbers that used leaded solders in my house's plumbing. They shut up and redid the joints.

[J0K3RX]

I use Alpha Metals Alpha Purecore and Alpha Aqualine 6000. Both have water soluble flux core and flow like melted butter and solidify very quick.. Best thing is that they clean off with a little bit of water and a brush, the end result is bright shiny diamond like solder joints, some of the best stuff there is in my opinion! The Alpha No-Clean is great also... Alpha Metals is pricey but worth it! You can find it on ebay from time to time and I have seen it for half the price.

http://www.hisco.com/products/category/Soldering-Desoldering/Solder,-Wire/Water-Soluble

[kingswayguitar]

used lots of 63/37 and it's quick and easy, not like the stuff you described (sounds like you got some bunk)

[J0K3RX]

used lots of 63/37 and it's quick and easy, not like the stuff you described (sounds like you got some bunk)

Agree...

I have come across contaminated/bad rolls of solder before but not very often. Generally 63/37 rosin core is great, even the Radio Shack stuff is good... Lead free SUCKS! Anybody that says otherwise has probably inhaled to much flux fumes I refuse to work with it, not even on my kids toys when a wire breaks...

My father-in-law gave me a roll of ancient Fred Flintstone rosin dinosaur sh!t core solder one time and I nearly died from the smoke and it looked like hell! Threw that sh!t in the trash, probably got buried in a land fill and now it's in my drinking water That would explain my twitchy eye and my periodic inability to control my bowels  

If you get a chance you might try 62% tin, 36% lead, 2% silver, some people swear by that stuff for audio type applications. Supposedly flows better, lower melting point, stronger, and has a higher conductivity but I think it's relatively small if at all... But sure looks pretty
 
Bottom line: if you got stuck with some sh!tty solder it probably ain't gonna get better the more you use it so throw it in the back of the cabinet and use it for minor repairs where quality is not an issue. Then go get some good stuff

[alparent]

I  guess that's what you get for being a cheep bas......!
Going to my local electronic store tomorow and get me some real solder.
Should I stick with trusty 60/40 or get 63/37?

So according to you guys I'll have as nice a joint with 63/37?

[R.G.]

60/40 works fine, and 63/37 works fine - if that's what you really get. The differences are then in the quality of the flux if it's flux cored.

[Jdansti]

I've found that no matter what solder I use, my life is easier when I use a little dab of flux from a flux pen like this one:

http://www.mgchemicals.com/products/prototyping-and-circuit-repair/pens/rosin-flux-835-p/

[greaser_au]

Interestingly I've been unable to find the 'usual' soldering technology graph on the 'net.  63/37 (Sn/Pb) has the lowest temperature liquidus, and it's an alloy that has no plastic phase. In the factory,  standard solder for hand and machine soldering was Kesters 60/40.  Also, it was cheaper to toss a quarter of a ton of solder from the wave machine than get an alloy analysis to meet the quality requirements.   

More factory gossip: we  used to use 40/60  Sn/Pb for soldering of pins on boards that were to be later soldered 'blind' - it required a #8 (800 degF ) weller tip for proper wetting.

david

[duck_arse]

ahhh, the weller. is there a better iron? these days, probably.

overheated solder (60/40 at least) goes crystalline and bad. if 63/37 has a lower melt temp, and you use higher tip temps, either it's not 63/37, or you're making bad, overheated joints.

having said that, I've often had solder "boiling" around pins. I get a small bubble of gas bursting just after the iron leaves the joint. (60/40, weller #7)

[greaser_au]

ahhh, the weller. is there a better iron? these days, probably.

overheated solder (60/40 at least) goes crystalline and bad. if 63/37 has a lower melt temp, and you use higher tip temps, either it's not 63/37, or you're making bad, overheated joints.

having said that, I've often had solder "boiling" around pins. I get a small bubble of gas bursting just after the iron leaves the joint. (60/40, weller #7)

Better than the Weller WTCPN?  for consistency & repeatability?  even now, I'd probably still say "not likely"

Again, factory gossip,  heating the boards to 60+ degrees  before feeding them to the wave machine increased the passrate markedly - got rId of the gassing completley. screen wash was the next issue!

david

[R.G.]

overheated solder (60/40 at least) goes crystalline and bad.

Overheated solders of all kinds boil can boil off the flux and oxidize the metals in the melt. The oxides change the composition of the alloy in low-mass joints and cause crystalization as the melting temp changes with the metal mix, and the oxides are included at the crystal grain boundaries as the crystals form. It's due to the action of oxygen in the air. More flux to exclude oxygen generally fixes this up to the temp where the lowest boiling point metal in the alloy boils.

having said that, I've often had solder "boiling" around pins. I get a small bubble of gas bursting just after the iron leaves the joint. (60/40, weller #7)

Residual volatiles held inside the hole, probably. Soldering irons don't get hot enough to boil either tin or lead.

For more than you ever wanted to know about solder, start with http://en.wikipedia.org/wiki/Solder

Again, factory gossip,  heating the boards to 60+ degrees  before feeding them to the wave machine increased the passrate markedly - got rId of the gassing completley.

Don't all modern wave soldering machines have a preheat tunnel to ramp the temp slowly for this reason and also for avoidance of thermal shock on parts before hitting the solder?

I am NOT an expert with wavesoldering machines - just a beginner's understanding.

[greaser_au]

Again, factory gossip,  heating the boards to 60+ degrees  before feeding them to the wave machine increased the passrate markedly - got rId of the gassing completley.

Don't all modern wave soldering machines have a preheat tunnel to ramp the temp slowly for this reason and also for avoidance of thermal shock on parts before hitting the solder?

I am NOT an expert with wavesoldering machines - just a beginner's understanding.

The wave machine I used was ancient, even in the '80's! Yes there was a preheat tunnel, and a wave fluxer.  It still took some rad skillz to run it properly - it had hammertone paint, and all!  Better results were had (all-round)  if the boards were baked at 60 degrees (celsius) for a few hours prior to presenting them to the machine- I expect it got rid of any excess volatiles and water in the fibreglass!

[Jdansti]

From R. G. >More flux to exclude oxygen generally fixes this up to the temp where the lowest boiling point metal in the alloy boils.

This might explain why the flux pen I use works so well. It's a cheap way to get a little more flux without slathering the stuff all over the place. I can see a huge difference when I forget to use it when I solder a joint or tin a wire.

[duck_arse]

wtcpn - there must be irons these days that don't get as hot a handle, especially in australian summers. and have a better power connector.

I have the same one I bought ~1980. except for the lead. and the switch. barrel. element. tips. but it's still my favourite.

who were you wave soldering for in the 80's, greaser?