use 2 different solder?
I have 2 different solder, one is 1.0mm SN 60%, Pb 40%. The ohter one is .56mm 60% Sn, 38% Pb, 2% Cu, Now I use the 1.0mm for tinning the wires and the 0.56mm for preparing the solder points. I wonder if this could anyway affect my soldering bit negatively? I've noticed that when using this combination some of the iron bit gets black.
Does anyone know if this could damage my bit in the long term?
The solder types shouldnt do too much adverse damage to your iron as long as you remember the obvious thing of not using the plumbers acid flux solder. The tip on the soldering iron will need to replaced eventually, they can and do wear out over time. As for the tip getting blackened it could be just getting dirty. do you use a small wet sponge with your soldering iron to keep the tip clean whilst using the iron? that will help. Also remember do *NOT* file the tip to make it smaller or cleaning it up. That will absolutely ruin the tip.