Ok I tried tinning my solder tip, and the solder stays on, but it gets dirty looking. The tip is not shiny, the solder on it is dull and dirty. I think the rosin in the solder burns up on the tip and contaminates the solder. I've wiped it off with a dry tissue, then re-added solder several times, it just ends up like that. Usually, I just keep the tip clean of any solder, and my solder joints are nice and shiny. If I tin it, the solder on the tip gets into the joint and contaminates it. What do I do? I don't have any problems soldering..