1) If it's glasless... It's not a mig welder. MIG = Metal insert gas What you have is a flux core, wire feed arc welder. It uses a .030" or .035" welding wire with a flux cored center to sheild the weld puddle. Where a MIG would use a solid wire and argon/co2 gas from a bottle to sheild the weld. Flux core is pretty junky IMHO. It's hard for even pro welder to get a good bead from those things. The flux core wire always leaves alot of slag behind. For what your welding, use .035" wire, set welder to highest amp/heat setting.. Probbly around 90 amps Use an angle grinder to grind the steel clean. You want all parts where the joint will be to be shiny new looking steel. Also cut/grind tube for a good tight close fit. You want the smallest gap between the two as you can get. Keep about 1/4" to 3/8" stickout at all times (welding wire sticking past end of nozzle) Keep the wire directed at the leading edge of the weld pool as you make your bead. Adjust your wire speed based on your travel speed. You want to hear a good sizzle like fring of bacon while you weld, not a pop, sizzle, pop, pop. If your wire speed control is 0-10 you will be somewhere between 4-6 You need to keep the gun steady to get a good bead. What I do is hold gun in my right hand and rest the nozel of gun on my left hand index finger, with the side/bottom of my left hand resting on work pc. A drag or pull gun technique will give you a bit more penetration and a narrower bead. A push gun technique will give you a bit less penetration, and a wider bead. (drag/pull will probbly work best for you) Keep the gun angled about 10* from the work