You are going to have to really understand the parameters of aluminum welding before you even consider doing it. There is no need to increase the damaged area by doing welding on aluminum if you are inexperienced. You will end up with more expense than you anticipated.
First, your welder isn't ideal to use. You would have to change the liner, or get a completely new MIG gun assembly to use aluminum wire. You cannot use a liner that already has had steel wire run thru it...... CONTAMINATION!!! Aluminum is extremely finicky regarding cleanliness....... aluminums' motto is: "Cleanliness is next to Godliness." The aluminum joints needs to be cleaned with a good SS brush with acetone. You cannot use any tools that have been used for steel such as grinding wheels/discs or even wire brushes. Most who do aluminum welding keep their tools segregated so as not to contaminate.
Next, aluminum runs HOT & FAST!!! You gotta really have some serious seat time to get used to the fast pace of alum. MIG. It's not hard. It just takes xtra steps to understand & comprehend the difference in steel & aluminum processes. I would probably find someone nearby who has done aluminum welding & simply ask him if he would be willing to take you under his wing to learn how to properly weld it. It would really enhance your welding education. Do some searching on the forum for aluminum threads & at least, get some understanding of what is involved.
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