Against every assumption, virtually everything can be sweetened. Aluminum castings are also easily weldable in most cases. Some things are just better - others again somewhat worse.
The welding result often lies on the material to be welded. It often contains welding-promoting accompanying substances, which lead unconditionally to bubble formation and thus strongly influence tightness and stability. Then the most extraordinary welding filler (welding wire) does not help. To 95% we welded with AlSi5 and ALSi12. In stock we also have some other alloys like. e.g. AlMg3, AlMg5, and ALMg4.5Mn.