7018 Vertical Welding – Mastering The Vertical Up Technique
To succeed with 7018 vertical welding, use a “vertical up” progression with your machine set to DCEP (reverse polarity). Focus on building a “shelf” of solidified metal at the bottom of the joint and maintain a tight arc length to prevent the molten puddle from sagging.
Reduce your amperage by roughly 10-15% compared to flat welding and use a slight “Z-weave” or “triangle” motion, pausing briefly at the sides of the weld to prevent undercut.
Most welders agree that moving from flat or horizontal positions to vertical work is one of the most challenging hurdles in a metalworker’s journey. Gravity becomes your constant opponent, trying to pull the molten puddle out of the joint and onto your boots.
I promise that once you understand how to control the heat and manipulate the rod, 7018 vertical welding will become one of the most reliable tools in your fabrication arsenal. It is the gold standard for structural integrity in the DIY workshop.
In this guide, we will preview the essential machine settings, rod angles, and the specific “shelf” technique required to master this position. We will also cover how to avoid common pitfalls like undercut and slag inclusions that often plague beginners.
Understanding the Mechanics of 7018 vertical welding
Before you strike an arc, you need to understand why the 7018 electrode is the preferred choice for vertical work. This is a low-hydrogen, iron-powder electrode designed for high-strength applications.
The “70” stands for 70,000 psi of tensile strength, while the “1” indicates it can be used in all positions. The “18” tells us about the coating and the current, specifically that it works best on DCEP (Direct Current Electrode Positive).
When performing 7018 vertical welding, you are almost always welding “up” rather than “down.” While vertical down is faster, it lacks the deep penetration and structural strength required for critical loads.
Welding vertically upward allows the weld puddle to stack on itself. This creates a much thicker, stronger bead that can handle the stresses of heavy machinery or structural home improvements.
Setting Up Your Welding Machine
Your machine settings are the foundation of a good vertical weld. If your amperage is too high, the metal will become too fluid and fall out of the joint.
If the amperage is too low, the rod will stick, and you will struggle with cold lap. For a standard 1/8-inch 7018 rod, you might weld at 125 amps in the flat position.
For vertical work, you should drop that range down to 105 to 115 amps. This slight reduction in heat gives the puddle a chance to freeze more quickly, helping you maintain control.
Ensure your machine is set to DCEP. This polarity puts more heat into the base metal, which is crucial for achieving the penetration needed when working against gravity.
Preparing the Workpiece for Success
One of the biggest mistakes DIYers make is failing to clean their material. 7018 is a “fast-freeze” rod, but it is sensitive to mill scale, rust, and oil.
Use a flap disc or a wire wheel to grind the joint down to shiny silver metal. You should clean at least one inch back from the weld zone on all sides.
If you are welding thick plate (1/4-inch or more), you must bevel the edges. A 30-degree bevel on each piece creates a 60-degree V-groove that allows the root pass to penetrate fully.
Proper fit-up is also essential. Use strong tacks at the top and bottom of your joint to prevent the metal from pulling apart or warping as you apply heat.
Mastering the Art of 7018 vertical welding
The secret to a perfect vertical weld is the “shelf.” Think of it as building a staircase where each new drop of metal sits on the one you just placed.
Start at the bottom of the joint and strike your arc. Hold the rod for a split second to allow a small molten pool to form at the base.
Once that pool solidifies slightly, it creates a physical ledge. Your goal is to keep adding metal to the top of that ledge as you move upward.
Maintaining a tight arc length is critical here. If you pull the rod too far away, the voltage increases, the arc gets hotter, and your “shelf” will collapse.
Keep the tip of the rod almost touching the puddle. This concentrated heat ensures the metal goes exactly where you want it without overheating the surrounding area.
The Importance of Rod Angle
Your rod angle should be slightly pointed up, usually between 5 and 15 degrees. This is often called a “lead angle” or “push angle.”
This upward angle helps the arc force push the molten metal into the joint. If you point the rod straight in or downward, the puddle will likely sag or “drip.”
Choosing the Right Travel Speed
Travel speed in vertical welding is a balancing act. If you move too fast, the bead will be thin and weak.
If you move too slow, you will put too much heat into the plate. This causes the metal to stay liquid for too long, leading to excessive reinforcement or “grapes” of metal falling off.
Common Weave Patterns for Vertical Work
While “stringer beads” (straight lines) are great for the root pass, you will often use a weave pattern for the fill and cap passes.
The Z-Weave Technique
The Z-weave is the most common pattern for 7018 vertical welding. You move the rod across the joint in a “Z” shape, pausing at each side.
The pause at the toes of the weld is the most important part. It allows the metal to fill in the edges, which prevents the dreaded undercut.
The Triangle Move
For wider gaps or root passes, some welders prefer a triangle motion. You move the rod up into the center of the gap, then back down to the left side, then across to the right.
This technique ensures the center of the joint is fully fused while building a substantial shelf to support the weld.
Safety and Protection in the Workshop
Vertical welding is inherently messier than flat welding. Because you are working upward, spatter and slag will fall directly toward you.
Always wear a heavy-duty leather welding jacket or leather sleeves. A simple cotton shirt will not protect you from the red-hot slag that 7018 produces.
Ensure your welding helmet has a clear lens and is set to the correct shade (usually 10 or 11 for 7018). Use a welding cap under your helmet to protect your hair and ears.
Proper ventilation is also key. 7018 electrodes produce fumes that you should not inhale directly. Use a fume extractor or work in a well-ventilated garage with a fan pulling air away from your face.
Troubleshooting Common 7018 Vertical Issues
Even experienced welders run into trouble when gravity is involved. Recognizing these issues early will save you hours of grinding.
Dealing with Undercut
Undercut looks like a small ditch or groove along the edges of your weld. It happens when the arc melts the base metal, but you don’t stay long enough to fill it back in.
To fix this, pause longer on the sides of your weave. Count “one-one-thousand” at each edge before moving back across the center.
Preventing Slag Inclusions
Slag inclusions occur when the molten slag gets trapped inside the weld metal. This often happens if your arc length is too long or if you don’t clean the slag between passes.
Always use a chipping hammer and a stiff wire brush to remove every bit of glass-like slag before starting your next bead.
Managing Porosity
7018 is a low-hydrogen rod, meaning it is designed to keep moisture out of the weld. However, these rods are hygroscopic—they soak up moisture from the air.
If you see small holes (porosity) in your weld, your rods might be “wet.” For critical projects, 7018 should be kept in a rod oven at 250 degrees Fahrenheit.
Rod Selection: 1/8″ vs. 3/32″
For most DIY projects involving 1/4-inch to 3/8-inch steel, a 1/8-inch rod is the standard. It provides a good balance of deposition rate and control.
However, if you are a beginner, starting with a 3/32-inch rod can make 7018 vertical welding much easier. The smaller rod requires less amperage.
Lower amperage means less heat in the workpiece, which makes the puddle much easier to manage. Once you master the 3/32-inch rod, moving up to the 1/8-inch size will feel natural.
Frequently Asked Questions About 7018 vertical welding
What is the best amperage for 1/8″ 7018 vertical up?
While every machine is different, most welders find success between 105 and 115 amps. If you are a beginner, start at 110 amps and adjust based on whether the puddle is sagging or the rod is sticking.
Can I weld 7018 vertical down?
Technically, you can, but it is not recommended for structural work. 7018 has a heavy slag that will likely run ahead of the puddle when welding down, leading to slag inclusions and poor penetration.
Why is my 7018 rod sticking at the start?
7018 can be notoriously difficult to restart. The flux often forms a hard “scab” over the tip. Tap the end of the rod on a piece of scrap or pinch the flux off with your gloved hand to expose the core wire before striking.
How do I stop the puddle from falling out?
The most common cause is a long arc. Keep the rod as close to the metal as possible without sticking it. Also, ensure you aren’t spending too much time in the middle of your weave; move quickly across the center and pause on the sides.
Conclusion: Practice Makes Permanent
Mastering 7018 vertical welding is a rite of passage for any serious DIY metalworker. It requires a combination of machine tuning, physical steadiness, and an understanding of fluid dynamics.
Do not be discouraged if your first few attempts look like “pigeon droppings” or “grapes.” Vertical welding is about muscle memory and learning to read the puddle in real-time.
Spend time on scrap metal before moving to your actual project. Focus on that “shelf,” keep your arc tight, and always prioritize your safety gear.
With enough practice, you will be able to produce welds that are not only aesthetically pleasing but also structurally sound enough to last a lifetime. Now, grab your stinger, dial in those amps, and start building that shelf!
