Is aluminum welding difficult? 
Aluminum is not bad at weldability.It is not easy to see the welding of the material first, then to master the characteristics of the material, and then the level of operation of the welder! 
The characteristics of aluminum is easy to oxidize, fast thermal conductivity, welding pool is not easy to distinguish, the weld is easy to produce porosity! So when welding, we must do a good job of cleaning before welding, master the air humidity and do a good job of preheating. There are a lot of welding points here, I will not elaborate on them.