Milad's 72in LED build

[Bloodasp]

I agree that a lot has to do with improer soldering techniques. I have yet to see solder meant for electronics without a flux core, even the lead free ones I have used always contain them, from the sound of what he said though that he had to scratch the component to get some soldering to happen he definitely needs it.
And also boring a hole through the track of an smd mounted component is not a good idea as they are normally too small that drilling a hole through them would likely cause it to peel off.