Electronic – Why does solder turn dull grey on the iron and exhibit poor wetting


I have a relatively new soldering iron. I can't remember when this started(and I've only used the iron 5-10 times) but I stopped being able to tin the tip. When I stick soldering to it it just balls up in one spot on the iron and then after 5 or 10 seconds on the tip, the solder turns a dull gray color(rather than shiny silver).

I have used nothing out of the ordinary on it. Only a brass sponge, a wet piece of cloth, and solder tip tinner/cleaner(which I only just started trying to use).

Even with the tip tinner, the tip will stay shiny(and conductive) for about 5 seconds and then rapidly turn a dull gray color, eventually even with a few black spots.

Is there something I can do to fix this? Did I just get a lemon tip or is this all normal(note I'm sorta new to soldering still)

Also, the soldering iron is this one with the included tip

Best Answer

Soldering iron tips should never be "clean" from everything. You must maintain a small amount of solder on them at all times to avoid oxidizing the iron plating (as in Fe iron, major component of steel, iron). After brushing excess solder and flux from the tip with a sponge, reapply a tiny bit of clean solder.

If your solder turns a dull grey, that would be due to it's oxidization, which means you're either waiting way too long or the iron is way too hot.

Tip tinner should only be used sparingly as it is fairly aggressive and will ultimately eat through the iron coating.