Welds that don't flow well

[oltrunt]

I hate it when that happens.  If this particular weld is cosmetic and not structural--say like a hatch frame, it'll probably be OK.  If there is ANY load on the weld grind it all out and do it again after a little practice with the puddle.  I also noticed your weld line isn't always following the seam but skipping around a bit.  Back grinding the edges to be butt welded goes better if you grind back the edges 45 degrees to the mid thickness of the material--both sides if possible.  As best I can tell, either stick or mig will get the job done equally well given knowledge of both the material and the rod (wire) you are working with.
Jack

[DoubleEagle]

I would recommend that you look for a welding course for beginners at a local vocational school or community college so that you can get on the spot guidance. One of your problems, beyond the wrong rod for the situation, is your vision of the welding puddle, and the steadiness of the arc length. Good welding helmets with auto-darkening and adjustable levels of darkness would help you see what is going on better. They are expensive, but very useful. The welding unit you have might only be AC with a short duty cycle like 10-20%, units that have AC and DC + or - with longer duty cycles can keep you going over long welds. Again, that costs money as well, but good used units can be found. I am still using a Lincoln Idealarc 250 that I bought used in 1984 at an auction.