Solder and Soldering Irons

[digital]

Why is it recommened to use only rosin core solder of 63/37 alloy ?

Whats acid core solder, and why is there bias towards using it ?

What is solder mostly composed of, isn't it lead ?


From my experience, why do soldering iron tips become black ?

Why do they even sell replacement soldering tips ?

Which is better higher or lower power soldering irons, which kind do you use ?

Are sharp skinnier tips better than fatter ones ?

 

[Nigel Goodwin]

Why is it recommened to use only rosin core solder of 63/37 alloy ?

It isn't anymore, it's recommended to use lead free solder. The exact ratio was based on almost the lowest melting point, the exact lowest wasn't used because it tended to fracture as it cools.

Whats acid core solder, and why is there bias towards using it ?

Because it's corrosive, it's NOT for electronics, it's for plumbing!.

What is solder mostly composed of, isn't it lead ?

It WAS lead and tin, I don't know what lead free uses?, but it's got a far higher melting point than lead/tin solder.

From my experience, why do soldering iron tips become black ?

Oxidisation!.

Why do they even sell replacement soldering tips ?

Because they need replacing when they wear out!, or you can use different size ones.

Which is better higher or lower power soldering irons, which kind do you use ?

Temperature controlled ones are best, otherwise use a small one for light jobs (soldering PCB's), and a large one for heavy jobs (soldering the chassis) - a temperature controlled iron will probably do both!.

Are sharp skinnier tips better than fatter ones ?

Again, it depends on the exact use!. Which is 'better', a sports car or a truck?, you might take your girl friend to the beach in a truck (but probably only once!), but transporting large crates in a sports car is difficult :lol:

 

[Dr.EM]

My lead free solder is 99.3% tin and 0.7% copper. It is essentially bronze! Takes a while for my 18w iron to get hot enough to melt it, but i've never had any trouble with damaging components from the heat.

 

[Nigel Goodwin]

Looking on the specs in RS Components gives:

Tin/Lead 60/40 melts at 183-188 degrees C.

Tin/Copper (Lead free) 99/0.85 melts at 227-240 degrees C.

Tin/Silver/Copper (Lead and rosin free) 95.5/3.8/0.7 melts at 217 degrees C.

Tin/Lead (rosin free) 60/40 melts at 340 degrees C.

 

[audioguru]

I understand that a cold solder joint that has fractured solder occurs because the wires have moved while 60/40 solder was cooling and changing from a liquid to a plastic mush then finally to a solid.
I have been told that 63/37 "electronic" solder doesn't have a plastic mush phase but instead changes directly and instantly from liquid to solid so there are fewer cold solder joints produced when it is used, compared to 60/40 original "electrical" solder.

My temperature-controlled soldering iron's tip doesn't turn black because it never gets to the rediculously high temperature of non-controlled ones.
It is plated so I never have to tin it. I wipe it on a damp sponge to clean it.
My tip is hot every day, and frequently all day long (and sometimes all night long) and lasts for years and years. It doesn't burn-out but actually finally wears-out.

 

[SkinnyBoy]

I understand that a cold solder joint that has fractured solder occurs because the wires have moved while 60/40 solder was cooling and changing from a liquid to a plastic mush then finally to a solid.
I have been told that 63/37 "electronic" solder doesn't have a plastic mush phase but instead changes directly and instantly from liquid to solid so there are fewer cold solder joints produced when it is used, compared to 60/40 original "electrical" solder.

that is correct.... not sure what Nigel Goodwin was talking about the 63/37 solder resulting in worse solder joints... =\

 

[Nigel Goodwin]

that is correct.... not sure what Nigel Goodwin was talking about the 63/37 solder resulting in worse solder joints... =\

I didn't say that! - I said the LOWEST POSSIBLE melting solder isn't used (and I've no idea what ratio it is!) because of problems while cooling.

 

[mstechca]

Why is it recommened to use only rosin core solder of 63/37 alloy ?

63/37 is uncommon to me. I use common rosin core solder. (60/40 ratio I think)

Whats acid core solder, and why is there bias towards using it ?

If you want to have a circuit board of just holes and fiberglass, use it. BUT if you want a professional circuit, I am against it. "acid core" should give you the indication that it is "extra powerful". "core" means what is inside the center of the solder.

What is solder mostly composed of, isn't it lead ?

I think tin and lead.

From my experience, why do soldering iron tips become black ?

How often do you clean your soldering iron tip? That might prevent it.
Mine is always black, and I just sand my tip :wink:

Why do they even sell replacement soldering tips ?

For people like me who sand my tip down to nothing :lol:
and for people who need a new tip. Not all items in this world last forever.

Which is better higher or lower power soldering irons, which kind do you use ?

I think mine is a 45W iron. I personally recommend lower wattage unless you have experience soldering. The higher the wattage, the hotter things get.

Are sharp skinnier tips better than fatter ones ?

I think it depends on your iron. To me, I use the tip that works with my iron.

Have you talked to some store employees? Maybe one of them can help you out.

 

[BRONI]

solder mixture

what is the exact solder mixture used on PCB components.Is it 50%tin 49.5%lead and .5% antimony?

 

[SABorn]

you might take your girl friend to the beach in a truck (but probably only once!), but transporting large crates in a sports car is difficult :lol:

Just wonder if you have a large girlfriend, then what is best?? lol.

 

[crutschow]

It's the environmental police that recommend lead free solder, not engineers. Tin/lead solder is easier to use so I recommend it for the average solder job, if you can still buy it. The environmental consequences of using that small amount of lead in your circuits is nil, in my estimation.

 

[KeepItSimpleStupid]

With 63/37 which has the same liquidus and solidus point (melts and solidifies at the same temperature), it's less likely to form solder bridges when soldering surface mount components.

Now there are complications with components. Some older components had a solder plating. SOME of the "new" solder doesn't play well when contaminated with tin. Lead solder is still a superior material due to the abscense of whisker formation with the new formulations.

Plumbing has switched to a Tin/Antimony system years ago. i don't mind that formulation at all.

 

[BRONI]

my question really is what would be the best solder mixture for conductivity.

 

[crutschow]

my question really is what would be the best solder mixture for conductivity.

There isn't enough difference between various solder mixtures to have any significant effect on the solder joint resistance since the solder layer between the two connections in the joint (which are normally in mechanical contact) that conducts the current is so thin.

 

[bryan]

Some interesting reading on "Tin Whiskers" that comes with using lead free solder.

https://www.guardian.co.uk/technology/2008/apr/03/research.engineering