The "lead free" solder bashing is dumb. Let me harken back to the years of heating an iron with an external source, putting flux on the joint with a small brush and then heating it with the now hot iron, waiting the right amount of time and adding solder to seal the joint.
Purpose of classes is to TEACH people how to do it right. Right tools, right skills, right training, learning how to do it right.
Sorry you don't have an iron that reaches the right temperature, sorry that you didn't buy solder that has the right mixture of flux and metal. Sorry that you didn't learn to heat the joint first, then apply solder. Sorry you didn't learn to clean the tip and reflux/re-tin it every so often between joints.
And I can carry the "sorry parade" to other items: drills, saws, punches, welders, 3D printers, flux-capacitors, photon-tubes,warp coils, Transmogrifiers, and of course the center of all IFI and Andy/Mark parts, unobtainium.
Mostly sorry that I keep forgetting that CD is a whine fest of people that can't pull together the right skills
while most of us go "Ok, that didn't have a happy ending, how do I fix that." Lead free solder is here, deal with it.