Hey there! A long time viewer, first time writer.
I recently got my 3rd solderig iron, it had a chisel tip and a sharp tip, My first irons tip lasted for about a year, the second ones didnt last for a day... 
And I managed to ruin the chisel aswell.... the first and second ones can hopefully be filed down to a point where i can retin the copper core. I'm going to get this solder in March: https://www.elfa.se/elfa3~ee_et/elfa/init.do?item=82-489-79&toc=0&q=wire+spool
From what I have seen on the interwebz, the easiest way to use a tin that has flux in it for the first time tinning the tip is wrapping some wire around the tip, before plugging it in. Will that work? And what are the general guidelines for making a tip last long? I think this topic is important enough to maybe get an episode of TBHS on it?
