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Soldering issues

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RealLifeYoda

New Member
Hi,
I've been trying to learn how to solder but have not managed so far.

Shortly explained:
I use:
* Temp controlled soldering station(usually about 400 celsius)
* Cleaning stuff that works well
* iron-tip w/ good surface area
* tried 2 different types of lead free solder(1mm thick and 0.35 mm)
* I practice by soldering through hole resistors into an experimental circuit board.

I've tried two techniques. One where I try not to touch the tip directly to the solder and instead heat the component leg and the circuit board. But when i did this it took way too long, so i got the tip to first melt a little solder on the tip and then use that solder to heat up the rest of the solder and component+cboard. But when I try this the solder never sticks onto the tip, it just melts onto itself into a ball(i attached a pic of this
Solderball.jpg
). Any ideas on how to fix this?

I also tried to solder by flowing heat directly from the tip onto the solder, component and cboard. But this only works about 1/4 times. The solder either becomes solid again way too quick or melts up into a ball on itself like I said before. Any ideas on how to fix this?
 
The iron tip needs to be "tinned" first, then kept clean but with a thin layer of solder still on it. Use the cleaner then immediately tin it and shake or wipe any excess solder off using a damp sponge (or damp cotton - bits of old denim jeans work well).

Note that Lead free solder is is nothing like as easy to work with as conventional tin-lead solder, it just does not flow as well.
The solder should also be a flux-cored type. I'd advise getting some 60/40 or 63/37 alloy, multicore or similar.

The thin layer of solder on the iron provides much of the surface area needed to heat the joint, so the solder you add to the joint flows quickly on contact with it. If that layer oxidises or burns away, the iron will not work well if at all.

Soldering works by forming something like a very thin layer of metal alloy between the solder and other metal; that can only work if heat from the metal is adequate to keep the solder liquid, and there is flux present to dissolve any surface oxides and allow the metals to combine within the joint.

A single sided PCB joint should flow almost instantly & a double sided still in less than a second, as there is more metal to heat.

(I normally have my iron at 350 - 360' for most things.)
 
So I should keep a little bit of solder on my iron when soldering a component?
Yes, it should always have a small amount of bright solder covering the tip, no enough that you can shake off the excess but a full layer.
Wipe it and re-tin by adding a small amount of flux cored solder any time it gets dull.
 
Yes, it should always have a small amount of bright solder covering the tip, no enough that you can shake off the excess but a full layer.
Wipe it and re-tin by adding a small amount of flux cored solder any time it gets dull.
Just thought I would update you. I just soldered with a slightly smaller and little more pointy tip and it worked a million times better. Literally seems to have solved all the currently existing problems. Thank you for the help.
 
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