ALUMINUM WELD Questions !!!!!!

I'm not a true pro in alum welding but I've welded steel, stainless and some alum for about 15 years (off & on). Alum has to be spotless clean...absolutly no dirt allowed. get a new grinder wheel or wire brush wheel and only use it for alum. clean it untill it looks good and clean and then clean it 1 more time. Any contaimination will give poor quality weld (contamination) and add dificulty to "wetting" in the bead. Heat wise you will have to watch for the edges of your added rod to determin if your arc is to cold , just right or to hot. to cold and it'll puddle or lay on top of the base metal. to hot and your base metal will sink away. good heat will make the base metal and added rod flow "wet" together or blend together smoothly. a few test welds on scrap would be helpfull. hope this helps