Also learned that some solder rolls are weighted. Not the solder but the plastic roll. The trick is they use heavy webbing between the hole and the outer layer the solder is rolled on. Some YouTube channel weighed them and more than half the stated weight is plastic https://youtu.be/lQ91gktACXw  

I had a similar experience recently. Thought my iron was faulty, biffed it and bought a flash new one, same result. Annoying to say the least, had to rework a whole bunch of s*** joins on a board afterward.

Found out bad solder is a thing. Just had a section of solder wire go on and acts like lead free. Extra flux etc makes no difference, it looks like aluminium burrs even when heated. Problem was it is under the pads on a microcontroller and shorting ground to power. New solder and drowned in flux it just turns to sand like beads and won’t flow.    I tested some more of the roll and it has sections that don’t melt correctly and are matte without shine and do flow or stick to the tip of the iron. The 2-mm from the heated end looks matte and nasty as well.    Ordered new roll of solder so that is more delay. still have other cool things on the go so back to learning to code.

First boards turned up. waiting on the rest of the components to arrive so can test them.      

Painted some speakers.  Just tidying up some old high end speakers magnet mounts. Original paint flaking from that white oxidation or the alloy. Used some left over touch up paint, so colour matched to the car.