do yourself a favor and slam that thing to about 300 WFS and 18.5 volts

used both machines both run very well it basically up to you . One obviously has a higher amperage capacity than the other i suggest look at the duty cycles and see which one is better and make sure they are compatible with you electricity in your shop or garage

Check your shielding gas. 30-40 cfh should be okay. make sure you are welding on the correctly polarity. Clean aluminum with stainless wire brush very good to remove all oxides off the metal before welding. Frankly it could be a lot of things when posting this kind question write down your parameter...

Silicon glass deposits formed from slica in the molten weld pool. Cause by the added deoxidizers in the wire. If welding a critical application wire wheel them off or hit them with slag hammer. Certain mig wires cause more of those deposits than others and also deposits and also depends on how much ...