Flux core mig gun vertical welding with LN-25

Hey fellow welders! I know vertical welding with flux core can be a real headache sometimes, but since I started using my LN-25, it’s become so much more manageable, almost enjoyable! I wanted to share some of my personal insights and techniques that have helped me achieve really strong and clean vertical up welds. First off, why flux core for vertical? For me, it’s all about portability and penetration. You don't need gas bottles, which is a huge plus when you're working on-site or in awkward positions. Plus, flux core wire generally provides better penetration and can handle slightly dirtier material than solid wire MIG, which is often a lifesaver. When tackling vertical positions, gravity is your biggest enemy, trying to pull that molten puddle down. Flux core's slag acts as a shelf, helping to hold the puddle in place as it solidifies. My go-to setup involves my LN-25 wire feeder – it's a beast for consistent wire delivery. For vertical up, I typically run a slightly lower voltage setting compared to flat welding, usually aiming for a crisper arc. Wire feed speed needs to be dialed in perfectly to prevent excessive buildup or a cold weld. A good starting point might be around 17-19 volts and a wire feed speed of 180-220 IPM with .035" flux core wire, but always do test pieces! Keep your stick-out consistent, usually around 1/2 to 3/4 inch. When it comes to the actual technique, a slight upward push angle (about 5-15 degrees) is crucial. You want to focus on keeping the arc on the leading edge of the puddle. I often use a 'Christmas tree' or a 'Z-weave' pattern, moving from side to side, pausing slightly at the edges to ensure good tie-in. The key is to watch that puddle closely; you want a consistent, even bead, not a lumpy mess. Small, consistent movements are better than large, erratic ones. For those of you with a Lincoln 180 MIG welder or similar compact machines, these principles absolutely apply! Just make sure your machine is capable of running flux core wire and you've got the correct drive rolls. Adjust your machine's voltage and wire feed speed settings according to your specific wire and material thickness, and then practice, practice, practice! The feel of the arc is universal, regardless of the machine. Now, let's talk about the bigger picture: TIG and MIG welding. While TIG produces incredibly precise, beautiful welds that are perfect for aesthetic work or thin materials requiring ultimate control, it demands pristine cleanliness and a significant amount of skill and setup. For robust structural work, outdoor repairs, or when speed is of the essence, especially with thicker metals, flux core MIG welding is often the more practical and efficient choice. It's generally more forgiving of surface contaminants and can achieve high deposition rates. So, while I love the artistry of TIG, my LN-25 and flux core are my workhorses for getting things done quickly and strongly. Hope these tips help you conquer your next vertical flux core project! What are your favorite techniques or challenges you've faced?