Cold, or just not shiny?

[mth5044]

I've been having trouble wild my solder joints not being as shiny as I am used to. Really not shiny at all. Most recently I've noticed on a turret board in an amp. From what I understand, a 'cold' solder joint is when one (or both) of the two components being soldered together (pad + lead, etc) I does not get heated to a high enough temperature to cause the solder to flow onto it. On a pad, it might look more like a drop of oil on water instead of coating the surface.

I also read a member on another forum saying 'any joint that is not shiny is a cold solder joint'.

I can actually see the turret sucking up the solder and creeping around it, which is all good, until I remove heat and it solidifies to a dull gray. I wouldn't call it pitted or anything, it's smooth, it's just not shiny. The component/wire isn't moving during cooling. Using a multimeter in connectivity mode, i get connections between places where these solder joints are used, so there is electrical connection. I've tried re-melting and it still remains dull. This has happened on almost every turret on the board. The solder holds stronger than a wire as I tried to yank it off and the wire snaps.

Would you call this a cold joint? Is it dull because of some kind of contamination? Should I worry about it or continue on? I'm already terrified of high voltage amps   

[bloxstompboxes]

It could be the type of solder you're using. Leaded solder will be shiny, lead free... not so much.

[GibsonGM]

Yup.  Or, soldering on a heavier item (turret?) vs. a PCB pad...might need a hotter iron. But not as likely...obviously, if it does this on each item, it's not the iron.
What wattage are you using? 20 to 25W is pretty standard. 

[mth5044]

It could be the type of solder you're using. Leaded solder will be shiny, lead free... not so much.

For the longest time, I thought it was unleaded. It's the radioshack'' 60/40 rosin core stuff... But now that I look at, it doesn't say lead free. It doesn't say lead at all actually. Or what the 60/40 even is. It has been shiny in the past.

Yup.  Or, soldering on a heavier item (turret?) vs. a PCB pad...might need a hotter iron. But not as likely...obviously, if it does this on each item, it's not the iron.
What wattage are you using? 20 to 25W is pretty standard. 

The iron I have is variable, but I crank it all up for the big turrets. It's max is 50W. I'll take a picture of the turret tomorrow.

[thelonious]

Or, soldering on a heavier item (turret?) vs. a PCB pad...might need a hotter iron.

Or change to a larger/flatter tip. More surface area contact = more heat transfer.

Any chance the joints are getting disturbed before they cool completely? If you get the turret hot enough, it will keep the solder molten for longer, resulting in more chance for a disturbed joint if you're not using a "helping hands" tool to really hold your work stationary. Or if your soldering iron cord is flapping against your turret board... etc.

[GibsonGM]

When mine 'go gray', I know I need to clean the tip.   Your iron should be fine, and you really don't need to go up to 50W! Remember that TOO hot isn't good, either....

If it was YOU, I think you'd see a few nice shiny joints by accident (ha ha), then some dull, some shiny....not consistently dull.   Clean the tip, try again, and see if it's ALWAYS dull, or not.  Bad batch of solder, somehow??   Get another roll and try with that - maybe your iron is messed up, not getting hot enough??

60/40 is 60% tin, 40% lead, and is standard for electronics work.  Rosin core.  I use the same Rat Shack stuff, and get shiny joints, tho... 

[wavley]

Did your turrets have lead free solder on them?

I've noticed when touching up lead free joints with lead solder I get dull joints (regardless of different heat settings and whatnot), suck it off, use lead solder, shiny joints.  I don't own any lead free solder and since I build cryogenic stuff that sometimes has to be space rated stuff at work I don't use it there either.  They *seem* to be reliable but ugly joints when I mix the two and I haven't had any fail on me.

http://nepp.nasa.gov/whisker/reference/tech_papers/2011-kostic-pb-free.pdf

[mth5044]

Or, soldering on a heavier item (turret?) vs. a PCB pad...might need a hotter iron.

Or change to a larger/flatter tip. More surface area contact = more heat transfer.

Any chance the joints are getting disturbed before they cool completely? If you get the turret hot enough, it will keep the solder molten for longer, resulting in more chance for a disturbed joint if you're not using a "helping hands" tool to really hold your work stationary. Or if your soldering iron cord is flapping against your turret board... etc.

Things aren't moving as occurs on components that have their leads wrapped around the turrets. The wires could potentially move, and if it happens while wiring and not not the stationary components I think it would be a problem, but it's happening on everything..

When mine 'go gray', I know I need to clean the tip.   Your iron should be fine, and you really don't need to go up to 50W! Remember that TOO hot isn't good, either....

If it was YOU, I think you'd see a few nice shiny joints by accident (ha ha), then some dull, some shiny....not consistently dull.   Clean the tip, try again, and see if it's ALWAYS dull, or not.  Bad batch of solder, somehow??   Get another roll and try with that - maybe your iron is messed up, not getting hot enough??

60/40 is 60% tin, 40% lead, and is standard for electronics work.  Rosin core.  I use the same Rat Shack stuff, and get shiny joints, tho... 

The solder was not a new roll and I ended up using the rest of it for the amp. It wasn't happening before, so not a solder problem (unless it can go bad...) Buf you're right, since it's always dull, it narrows it down to a few things and I think the tip is probably it. I give it a good sanding before I warm it up and try to clean it during use, but it's not as good as it used to look. I'll grab some new tips. Do you think a dirty tip just causes it to turn dull, or are they cold joints/ need to be removed. Unsold wrong the whole amp would be a bummer.

Did your turrets have lead free solder on them?

I've noticed when touching up lead free joints with lead solder I get dull joints (regardless of different heat settings and whatnot), suck it off, use lead solder, shiny joints.  I don't own any lead free solder and since I build cryogenic stuff that sometimes has to be space rated stuff at work I don't use it there either.  They *seem* to be reliable but ugly joints when I mix the two and I haven't had any fail on me.

http://nepp.nasa.gov/whisker/reference/tech_papers/2011-kostic-pb-free.pdf

Nah they were all clean before soldering with 60/40. I suppose will take a few days and desolder 

[Tony Forestiere]

Just for giggles, use an alcohol pad to wipe clean a couple of feet or so of your solder to remove any contaminants. My son has occasionally painted cars in the downstairs portion of the garage. My work area and "studio" is upstairs. I once got minor over spray from a clear coat job on my solder, and just could not get it to wet properly. Drove me nuts that solder that worked a couple of weeks ago went to crap.

[GibsonGM]

Good advice, Tony.     A bad tip can bung things up, yes.   Honestly, if they are mechanically ok and electrically ok, I wouldn't undo everything.
Sounds like you've TRIED to make the joints "go bad", and they're not....if it ain't broke...can't say what could happen over time, so I won't guarantee that statement, though!

Get a new tip and see what happens...think first, don't just jump in and desolder. Might be able to reheat them with a new tip!   I've had odd things happen when my tip gets old....and sanding/filing is actually said to make them worse! (altho I will use a file as a last resort sometimes!).     

You make sure your tip is prepped (wetted), right?   What diameter solder?  I like .062" for most things.  Too fat a dia. might also cause this, or a fan blowing on the parts (I've seen that happen, they go gray, cool too fast...)

Really weird, man, sorry you're having this issue!

[mth5044]

Just for giggles, use an alcohol pad to wipe clean a couple of feet or so of your solder to remove any contaminants. My son has occasionally painted cars in the downstairs portion of the garage. My work area and "studio" is upstairs. I once got minor over spray from a clear coat job on my solder, and just could not get it to wet properly. Drove me nuts that solder that worked a couple of weeks ago went to crap.

That is a great idea! It may even be the compnents themselves that are covered in junk. I've had the amp in the garage for a long time, not really protected. I've got some new tips on the way, I'll desolder a few places, clean up and see what happens. I ran out of the old solder, so I can't tell if it was on that or not anymore, unfortunately.

Good advice, Tony.     A bad tip can bung things up, yes.   Honestly, if they are mechanically ok and electrically ok, I wouldn't undo everything.
Sounds like you've TRIED to make the joints "go bad", and they're not....if it ain't broke...can't say what could happen over time, so I won't guarantee that statement, though!

Get a new tip and see what happens...think first, don't just jump in and desolder. Might be able to reheat them with a new tip!   I've had odd things happen when my tip gets old....and sanding/filing is actually said to make them worse! (altho I will use a file as a last resort sometimes!).     

You make sure your tip is prepped (wetted), right?   What diameter solder?  I like .062" for most things.  Too fat a dia. might also cause this, or a fan blowing on the parts (I've seen that happen, they go gray, cool too fast...)

Really weird, man, sorry you're having this issue!

I'll defintiely try to remelt with a new tip. Thanks for the .... tip. I use 0.032-0.064" depending on what spool I grab, I don't have anything bigger. No need to be sorry, I appreciate all the thoughts and comments you guys put forth. I'm hoping a new tip sets some of this straight

[GibsonGM]

It should...or new solder (like Tony said, contamination, or "oxidation"? Bad manufacturing?).    I like 'em shiny, too!  Hard to trust what looks like a bad joint.  Good luck, let us know!