I only use thin solder when soldering components (0.8 mm)
I never USED to be a big fan of thinner solders - preferring to use 1mm BUT lately I have been using 0.8mm from WES (made in Taiwan) and it is better than anything else I have ever used. Proper FULL lead count and excellent flux....lead free solder is just wank....a bit like McNuggets, Chicken nuggets without containing any chicken - - - now that is 100% McWank 
Lead free solder is absolute CRAP. Being an electronics tech, theres nothing i hate more than trying to desolder a component that has been soldered with lead free solder. And its difficult to tell if the solder joints in any electronic piece of equipment are good or not these days coz all lead free solder joints look bad from the factory, even when they are ok!!
