Every diy in electronics has to deal with it every now and then: soldering. When I started as a youngster, frequently a project I finished didn’t work. After investigation, the reason often was a bad soldering joint. All the more reason to pay attention to this craft.
An important aspect when soldering are the materials used. I use an older Weller magnastat. The operation and characteristic are described on the Hackaday site.
In brief: the element is heated until the curie temperature of the magnet. Then the magnet will temporary loose its magnetic characteristics. A little spring will force the contacts in an open position and consequently the heating will stop. Temperature will drop under the curie temperature again. The magnet regains it’s magnetic characteristics and the contact will be pulled in a closed position again by the magnet. The heating starts again.
From this type of iron you hear a ticking sound, you even can feel it. I got used to it, I think everyone will eventually.
In my post about the turret I explained how important it is to apply sufficient heat. Soldering is an art, you need to have a feeling for it. I add a movie to show how the tin is “sucked” between the wires when enough heat is applied
Patience is a virtue.
I use a 380 degrC tip and preferably one with a sharp point. All depends on your own preferences and the applications.
Make sure the sponge is wetted when you solder. You will see the tip gets black during your work, this pollution will eventually end up in your joints. So weep it off frequently.
I use a hand pump with Teflon tip for the big joints and litze wire for smaller work.