Stick Welding 7018 Vertical: A Complete Field Guide

A maintenance welder once told me that a 3/8-inch fillet running straight up a column plate looked easy — until the second pass dropped a lump of slag right back into the molten pool and the bead went flat and porous. Vertical 7018 is the position that separates a certificate on paper from a weld that passes inspection, and almost every struggle with it comes down to a handful of controllable variables.

Why Vertical 7018 Is the Skill Test Every Stick Welder Faces

A maintenance welder once told me that a 3/8-inch fillet running straight up a column plate looked easy — until the second pass dropped a lump of slag right back into the molten pool and the bead went flat and porous. That single sentence captures why vertical 7018 has a reputation. It isn’t harder in theory; it’s harder because gravity works against you every second the arc is lit.

What “Stick Welding 7018 Vertical” Actually Means

When someone says stick welding 7018 vertical, they mean shielded metal arc welding (SMAW) with an E7018 low-hydrogen electrode, running a weld in the vertical position — either straight up (vertical uphill) or straight down (vertical downhill). The workpiece is oriented vertically, so the welder is fighting a molten puddle that wants to sag, drip, and run ahead of the arc.

The electrode designation itself tells you why 7018 is the default rod for this job. Following AWS classification conventions, the digits break down like this:

• 70 — a minimum tensile strength of 70,000 psi for the deposited weld metal.
• 1 — a minimum weld size designation of 1/16 inch, indicating all-position capability in that classification family.
• 8 — a basic, low-hydrogen coating type (the “X” position in the full AWS pattern governs usable positions, and 7018 is qualified for flat, horizontal, vertical, and overhead work).

That basic coating is why 7018 dominates structural and code work. It produces weld metal with controlled diffusible hydrogen, which matters enormously for cracking resistance in restrained joints. The American Welding Society writes the electrode classification system and the structural codes that depend on it, and low-hydrogen consumables sit at the center of both.

Why Gravity Is the Real Opponent

In flat position welding, gravity helps you. The puddle settles into the joint, reinforcement lays down naturally, and the slag floats to the top where it belongs. Flip the joint vertical and every advantage reverses:

• The molten pool wants to run downhill before the leading edge freezes.
• Slag, being lighter than steel, tries to float up and around, but in vertical welding it can also pool and get trapped ahead of your arc.
• The rod shortens as you burn it, changing your arc length and angles mid-pass if you aren’t compensating.
• Falling slag and spatter land toward your hands, hood, and shoulders.

Everything you do vertically is a controlled negotiation with those forces: enough heat to fuse the root, not so much that the pool collapses; a weave that stacks cleanly on the previous shelf; pauses short enough to avoid sag but long enough to wet out the toes.

Vertical Fillet vs. Vertical Groove

Two joints show up constantly in vertical work, and they behave differently:

• Vertical fillet (T-joint or lap): two plates meeting at an angle, welded in the corner. The classic structural example is a fillet running up a column plate or stiffener. Practical experience caps E7018 vertical fillets at roughly 3/8-inch leg sizes per pass sequence before sagging and uneven fusion become difficult to control. Larger legs are built with multiple passes.
• Vertical groove (butt joint): beveled plates welded in a V or J groove, almost always run uphill for fill and cap. This is the joint that shows up in qualification testing — a 3G vertical groove plate is one of the standard positions tested with 7018, alongside 4G overhead, and it’s a common benchmark in AWS Certified Welding Inspector exam preparation.

What This Guide Will Cover

By the end of this article you’ll have a working method, not just descriptions:

1. What the 7018 electrode is, how it behaves, and how to store it properly.
2. Joint prep and machine setup that prevent problems before the arc starts.
3. Concrete starting amperage by rod diameter for vertical position.
4. The uphill motion itself — weave shape, pauses, angles, and where to look.
5. Uphill vs. downhill decision-making, including when a downhill root pass is acceptable under a written procedure.
6. Defect diagnosis: undercut, sag, trapped slag, porosity, cold lap, and how to correct each one.
7. Multi-pass sequencing, interpass temperature, and inspection-minded self-checks.

Stick welding still earns its keep on job sites precisely because one rod, one machine, and one operator can go anywhere — see Advantages of Stick Welding: Why SMAW Still Wins — but vertical 7018 is where that versatility gets tested. The OSHA welding and hot work guidance and NIOSH welding hazard resources also remind us that vertical and overhead work increase exposure to falling spatter and fumes, so technique and safety habits develop together.

If you can run a clean, defect-free vertical 7018 fillet or groove on demand, you can pass a plate test, handle structural field work, and diagnose your own mistakes in seconds. That’s why this position separates a certificate on paper from a weld that survives inspection — and it’s exactly what we’ll build toward, one variable at a time.

Before you can run a clean vertical bead, you need to know what is actually melting in your hand. The E7018 is not a mystical rod; it is a precisely classified tool, and the classification is stamped right on the packaging.

Reading the AWS Electrode Code

In the American Welding Society system, the “E” simply stands for electrode. The first two digits, 70, mean the finished weld metal has a minimum tensile strength of 70,000 psi (70 ksi) — roughly matching mild structural steel. The third digit, 1, tells you the rod is qualified for welding in all positions: flat, horizontal, vertical, and overhead. That single digit is why 7018 shows up in your vertical work instead of a 7024, which is a flat-position drag rod with a heavy iron powder coating. The final digit, 8, identifies the coating type: a low-hydrogen, potassium-bearing flux, which is what makes the rod usable on AC as well as direct current electrode positive (DC+, often called “reverse polarity”).

Why the Low-Hydrogen Coating Matters

The “basic” flux on a 7018 does two jobs at once. First, it shields the arc with a gas envelope while releasing very little hydrogen into the puddle. Hydrogen is the enemy of strong steel: it migrates into the cooling weld and can cause delayed cracking days later, sometimes on a job that looked perfect on Friday. Second, the flux yields a fluid, heavy slag that floats impurities up and out of the molten pool.

That fluid slag is a blessing in the flat position and a nuisance vertical. Compared to the thin, crusty, fast-freezing slag of a 6010 or 6011 cellulose rod, 7018 slag stays hot longer and wants to run downhill with gravity — right onto your fresh shelf or into your next arc start. This is why chipping and wire-brushing discipline between passes is not optional on a multi-pass vertical run. Every trapped slag line between passes is a defect waiting for the inspector.

For a useful contrast, compare this with the flux-cored and gas-shielded alternatives in our guide to all-position welding rods, where the “all-position” claim is earned very differently.

Current, Polarity and Rod Diameters

7018 runs on AC or DC+, and most welders prefer DC+ for a smoother arc and slightly deeper penetration. Manufacturer literature — Lincoln Electric, ESAB, and Miller all publish nearly identical tables — gives roughly these ranges:

Rod Diameter	Typical Current Range	Common Vertical Use
1/8 inch (3.2 mm)	90–130 A	Root and fill on light structural, the classic vertical-up learner rod
5/32 inch (4.0 mm)	110–160 A	General fill and cap on 3/16-inch-plus plate
3/16 inch (4.8 mm)	150–220 A	Heavy fill and capping passes on thick groove welds

Vertical welding almost always pushes you toward the lower half of these ranges. Excess amperage on an uphill 7018 is what produces sag, undercut, and a flat, porous bead.

Storage and Handling: The Part Everyone Skips

Here is the uncomfortable truth about low-hydrogen electrodes: the coating is hygroscopic. Open a sealed pack on a humid day and the flux starts absorbing moisture from the air. That absorbed water re-enters the puddle as hydrogen, undoing the entire reason you chose 7018 in the first place.

Industry practice, aligned with AWS recommendations, is straightforward:

• Keep opened packages in a rod oven held at the manufacturer’s specified re-drying temperature (commonly in the 500–800°F range for 7018, but check your specific rod’s data sheet).
• Limit ambient exposure. Manufacturers commonly publish allowable open-air exposure windows in the range of roughly 4 to 9 hours before rods must be returned to the oven or discarded, depending on humidity and the specific electrode.
• Only take out what you will weld in a short session, in a sealed portable rod quiver if you must carry rods to the joint.
• Never re-use exposed rods on code or structural work once the exposure limit is exceeded without proper re-baking per the manufacturer.

Finally, remember that low-hydrogen flux also produces fumes that deserve respect. Position the work so fumes stay out of your breathing zone, and follow the ventilation guidance in OSHA 1926.353 and the NIOSH welding topic page.

Know the rod, keep it dry, and the vertical technique in the sections ahead becomes far easier to execute.

Setup That Makes or Breaks a Vertical 7018 Run

Vertical welding punishes lazy prep more than any other position. Flat work forgives a 7018 dragged across a half-cleaned joint; straight up, gravity exposes every shortcut: a drifted tack gap, a root face left too thick, a clamp biting into paint. Nearly every vertical failure traces back to a decision made before the arc was struck.

Joint Preparation and Fit-Up for Vertical Grooves

The standard groove for a vertical 3G test plate is a single-V: 30 degrees per side, a 60-degree included angle. Widen it and the puddle loses the sidewall support it needs to stay put; close it and the arc cannot reach the root without wandering. Manufacturers such as Lincoln Electric publish joint details for qualified procedures; working to those drawings beats eye-balling a bevel on a bench grinder.

Two dimensions matter more than the bevel angle:

• Root face — the small un-beveled land at the bottom of the joint. Too thick and the first pass never ties through; too thin and the arc blows the edge away before the puddle can fill it.
• Root opening — the gap between the plates. Match it to the rod: a 1/8-inch electrode pairs with about a 1/8-inch opening, and the rule holds roughly in proportion as rod size grows.

Rod diameter	Common root opening	Typical use
1/8 in	1/8 in	Root pass, thinner plate, test work
5/32 in	3/16 in	Fill and cap on medium fillets
3/16 in	3/16 – 1/4 in	Heavy fill passes, thick groove welds

Fit-up discipline matters on vertical fillets too. Tack the ends first, check for twist with a square, then add the center tack. Tacks become part of the finished weld, so grind the toes of any tack that stops mid-joint and make sure each one is fully fused. A joint that closes as you weld changes root penetration mid-pass, one of the fastest routes to trapped slag.

Cleanliness: Mill Scale, Oil and Rust

Grind or brush the joint bright, at least an inch back on either side of the groove. Mill scale, oil, paint and rust all outgas under the arc and cause porosity. The 7018 basic coating is less forgiving of contamination than cellulose rods such as 6010, which is why a 6010 root stays popular on dirty field joints while 7018 handles the fill and cap where cleanliness can be controlled.

The same principle spans processes: an aluminum joint prepped carelessly goes porous from a thin oxide film, and Aluminum Cleaner for Welding: How to Prep Aluminum Right covers that prep in detail. Clean metal means a stable arc, and a stable arc is the whole game vertically.

Heat Input: Amperage, Travel Speed and Arc Length

Smaller rods are preferred vertically because they lower both deposition rate and heat input, the control you need against a sagging puddle. A 3/16-inch rod that runs beautifully flat can deposit metal faster than gravity will accept it uphill. Travel speed sets heat input alongside amperage: pause at each toe long enough to wet out, then keep moving so the puddle does not pile up on the underside.

Arc length should stay tight, roughly the rod diameter or less, especially on AC, where the 7018 arc is less stable than on DC electrode positive. A long arc spreads heat away from the joint and drags the flux shielding out of position.

Clamp the work to clean, bare metal as close to the joint as the fixture allows, opposite the side you are welding. A clamp biting into paint or rust forces current to find another path, and the symptom is an arc that wanders and a puddle that will not behave.

PPE and Ventilation

Vertical-up work puts your head directly above the arc, so fumes rise straight into your breathing zone. OSHA 29 CFR 1926.353 (and the parallel general industry standard 1910.252) requires mechanical ventilation whenever fume concentrations exceed acceptable limits, with local exhaust taking priority over general dilution. Add a shaded helmet, FR jacket, gloves, closed shoes, and a respirator where the fume assessment calls for one. NIOSH’s welding topic page covers the health risks in depth.

Get these five things right — geometry, fit-up, cleanliness, heat control and dry consumables — and the technique sections that follow become far easier to execute.

Choosing Amperage and Rod Size for Vertical Position

When running stick welding 7018 vertical uphill, amperage isn’t about brute force, it’s about restraint. With gravity working directly against you, your goal isn’t to flood the joint with heat. It’s to maintain just enough fluidity to fuse properly without allowing the puddle to sag, drip, or run down the plate. Getting this balance right is often the difference between a stackable bead and a glob on the floor.

Starting Points By Rod Diameter

Every welding machine varies slightly, however there are tried and tested starting points to get you in the ballpark for vertical-up on mild steel. The key is remembering that you’ll be running cooler than you would in the flat position:

Rod Diameter	Typical Flat Range (Reference)	Vertical-Up Starting Range
1/8″ E7018	90 – 120 A	75 – 100 A
5/32″ E7018	110 – 140 A	90 – 120 A

As a general rule, expect to run about 10–20% below your flat-position setting for the same rod. For 1/8-inch 7018, 75–100 A is the most common starting zone to dial from. For 5/32-inch 7018, most welders begin around 90–120 A. Many welders avoid 3/16-inch and above vertically for structural work, opting to build larger welds with multiple passes of 1/8″ or 5/32″ instead.

Read The Puddle, Not Just The Dial

The amperage number will only ever get you to first strike. From there, your puddle must dictate every adjustment. Look for a small, crescent-shaped puddle with a crisp, defined leading edge that is actively wetting into both toes of your fillet.

If the puddle is sluggish, won’t tie in, or leaves a rough, unmelted ridge behind it, you’re running too cold and are at risk of cold lap. On the other end, if the edges begin to roll over, sag downwards, drip, or look syrupy, you’re running too hot. Excessive amperage on vertical uphill increases fluidity, leading to sagging, dripping, and trapped slag at the toe of the bead.

Arc Length, Polarity, And Travel Speed

Of all the variables for 7018, arc length is the most unforgiving vertically. A short arc length (about one electrode diameter or less) is critical to keep the low-hydrogen flux coating’s shielding intact to prevent porosity and undercut. Think tight, almost to the point of lightly dragging the rod, as stretching the arc will instantly soften the puddle and invite slag inclusions.

For most setups, DC reverse polarity (DCEP) is the preferred choice for vertical-up. It provides the arc force needed to control the puddle without needing to run unnecessarily hot. When paired with this polarity, your travel speed needs to be deliberate. Move fast enough to stay ahead of the forming shelf, yet slow enough to allow full fusion into both toes. This is a balancing act that will improve drastically with focused practice.

Heat Input Management: Thin Versus Thick Material

Heat input control is paramount when switching between material thicknesses. On thin plate, around 1/8″ or lighter, stay towards the lower end of your vertical range and utilize tight stringers over wide weaves. Thin metal heats up exponentially, leaving very little room for error before burn-through.

On thicker structural plate, you have more thermal mass to work with, allowing you to creep towards the middle of the recommended range. Even then, restraint is king. For larger fillets, it’s far more code-friendly and controllable to build them with multiple passes opposed to trying to force one massive, hot weave into place.

Whether you’re practicing on scrap or working towards a structural pass, remember to reference the guidance set forth by Lincoln Electric and applicable AWS standards for your specific procedure. With patience, observation, and a disciplined hand, your amperage will become less of a guess, and more of a response to the puddle in front of you.

The Uphill Technique: Step-by-Step Vertical 7018 Motion

Everything before this was preparation. The rod is in the stinger, the plates are tacked, and only motion stands between you and a clean vertical fillet. Vertical-up 7018 is not a steady drag like a flat bead. It is a deliberate, repeatable cycle: establish the puddle, weave, pause at the toes, advance, and let each ripple freeze into a shelf for the next. Get the cycle right and the weld stacks itself. Get it wrong and you spend the rest of the joint fighting slag and gravity.

Work Angle, Travel Angle and Where to Stand

Start with geometry, because no amount of hand skill fixes a bad angle. On a vertical fillet, hold the work angle at roughly 45 degrees, splitting the difference between the two plates. On a vertical groove, keep the rod centered, close to 90 degrees to the joint, with a slight bias toward whichever bevel face you are filling at that moment.

Travel angle is where most beginners lose the bead. On vertical-up you use a slight backhand, or drag, angle of about 5 to 15 degrees off perpendicular, with the electrode pointing slightly upward into the puddle. That upward point is intentional. It directs arc force into the root and helps the molten metal freeze where you place it instead of sagging onto the plate below. Push angles that flip the rod downward are the fastest way to a lumpy, slag-filled weld.

Stand where you can actually see the toes, not the arc flash. If your shoulder or the stinger blocks the view, you are welding blind. Keep a comfortable rod extension, plant your free hand on the plate as a guide, and move your whole body up as the weld climbs rather than stretching your arm past its limit.

Starting the Root: Keyhole and the First Pass

Strike the arc at the bottom of the joint and hold it in place until a small, round puddle forms and the edges of both plates begin to melt together. On a vertical groove root, you are watching for a keyhole: a small, bright opening at the leading edge of the puddle that signals full penetration through the back of the joint. No keyhole usually means a cold, unfused root. A keyhole that keeps growing means too much heat or too slow a travel speed.

Work the root with a small side-to-side motion, sometimes called an S-pattern or a light lightning-bolt motion, tying both walls together as you climb. Keep the weave narrow here, roughly one to one-and-a-half rod diameters. Some written procedures handle the root differently, running a fast 6010 cellulose pass to punch through, then a small hot pass to flush the slag out before 7018 fills and caps. As covered in our comparison of all position welding rod options, 7018 is the position-rated rod, but the procedure always wins over personal preference.

The Weave: Triangle, Crescent and the Stack of Dimes

Once the root is tied in, you move into the fill and cap weave. Three patterns cover almost every vertical 7018 situation:

• Triangle weave. Move up and out to one side, across, then back down to center before climbing again. The downward stroke is short; the pause happens at each top corner.
• Crescent weave. A shallow arc from toe to toe, keeping the puddle slightly ahead of the solidifying metal. Good for wider cover passes.
• Side-step, or stack of dimes. Small lateral moves with a pause at each position, producing the classic evenly spaced ripple look.

Whichever you pick, the pause at each toe is the whole trick. Hold long enough at the side for the arc to bite into the plate and wash the metal in, then move. Too brief a pause leaves cold lap and lack of fusion; too long a pause melts away the corner and leaves undercut. Aim for roughly one second per side and adjust from what the puddle tells you.

Reading the Puddle and Topping Out

Watch the leading edge of the puddle, not the arc itself. You are looking for a consistent shiny crescent about one rod diameter wide that stays put as you climb. If the puddle starts to hang and bulge downward, slow down and narrow the weave so the metal freezes before it sags. If it looks thin and dry with visible porosity, shorten the arc and slow the travel slightly. The arc length on 7018 should stay tight, basically touching the puddle, because a long arc burns off the low-hydrogen coating and invites porosity.

Each weave should land about half on the previously solidified shelf and half on fresh plate. That is how the beads bond into one solid mass instead of a stack of separate bars. As you approach the top of the joint, shorten the weave and ease the travel speed so the crater fills completely rather than pinching off. A crater crack at the top of a vertical weld is a common reject, and it takes only a couple of extra seconds of arc time at the end to avoid it.

Vertical position is where stick welding earns its reputation. As noted in our overview of the advantages of stick welding, the process’s ability to go anywhere, on any alloy, with minimal gear is exactly why it still holds structural work that other processes cannot. Master this uphill motion on coupons and the same rhythm transfers straight to field work. Manufacturer technique guides from companies like Lincoln Electric and ESAB reinforce the same fundamentals: tight arc, narrow weave, deliberate pauses.

Uphill vs Downhill 7018: Which Direction Should You Run?

Ask ten structural welders about running a 7018 vertical-down and you will get nine eye-rolls and one story about a job that went wrong. With a low-hydrogen electrode, direction is not personal style. Gravity, flux chemistry and the code all lean the same way, and understanding why saves you from a bead that looks fine on the surface but fails on a bend test.

The short answer: for structural work, run vertical-up. Downhill has a narrow, specific role, and knowing where it fits is what separates a welder who follows procedures from one who just chases puddle.

Why Downhill 7018 Fights You

Downhill travel is naturally faster, because the puddle wants to run and you keep moving to stay ahead of it. That speed is the problem. The arc has less time to heat the joint walls, so the deposited metal lands on a surface that never got hot enough to truly fuse. The result is shallow, surface-biased penetration: a bead that sits on the joint instead of becoming part of it.

Slag is the second issue. A cellulose-coated 6010 throws a thin, watery slag that clears itself. A 7018 coating is basic and produces a thick, viscous, slow-setting blanket. Run downhill and that blanket tends to flow ahead of or underneath the advancing puddle, where it gets buried. You find it later as a grey line along the toe of the weld or a hollow, glassy streak under the bead. On a macro-etched test sample that is an instant rejection, and slag inclusion is one of the most common reasons a welder fails a plate qualification.

Heat input works against you more subtly. Vertical-up welds stay hot longer and cool more slowly, which lets a meaningful amount of absorbed hydrogen diffuse out before the metal hardens. A fast downhill pass quenches quickly and traps more hydrogen, which matters more as the plate gets thicker, the joint more restrained, or the base metal harder. On alloy steels, direction and procedure control become even less negotiable; you can read more in our guide to alloy steel welding electrodes.

What the Code Actually Allows

AWS D1.1, the Structural Welding Code — Steel does not ban downhill welding outright, but it allows it only when the process is covered by a qualified written procedure. The default, prequalified expectation for vertical groove welds made with low-hydrogen consumables is vertical-up for fills and caps. When an inspector hands you a WPS, the direction column is one of the first things you check. If it is blank or unreadable, uphill is the safe and correct assumption.

Manufacturers agree. Published electrode guidance from Lincoln Electric lists 7018 in all positions, but “all positions” means the rod is capable of running vertically, not that every direction is equally sound. Position capability and travel direction are two different questions.

The Sequence Most Structural Welders Actually Run

On pipe and heavy plate, the classic low-hydrogen procedure looks like this:

1. Root pass, vertical-down with a 6010 (or 7010) electrode. The cellulose arc is forceful and digging, freezes fast, and lets you control a keyhole without the puddle sagging.
2. Hot pass, vertical-down with a fast-freeze or filling rod, to burn out trapped slag and reinforce the root.
3. Fill and cap, vertical-up with 7018, where the slow, controlled puddle produces deep fusion, clean slag peel and low hydrogen.

An all-uphill 7018 sequence, root included, is equally acceptable and common on heavier groove welds where the root opening and bevel give enough access to establish penetration from the bottom. Direction is dictated by the WPS, not by habit.

Factor	Vertical Uphill (7018)	Vertical Downhill (7018)
Penetration	Deep, consistent into root and sidewalls	Shallow, surface-biased
Travel speed	Slow and deliberate	Fast, puddle chases you
Slag behavior	Blanket stays on top, peels cleanly	Flows ahead, gets trapped
Typical use	Structural groove fills, caps, heavy fillets	Thin sheet, cosmetic, non-code repairs
Inspection risk	Low when technique is right	High: lack of fusion and slag lines

When Downhill 7018 Does Make Sense

There is a legitimate case for turning the rod downward: thin material. On light-gauge steel where vertical-up would simply melt the edge away, a slightly under-ampered 7018 run downhill gives a fast, shallow bead with minimal burn-through. It is a handy trick for patch panels, brackets, drip pans and cosmetic out-of-position work where the joint carries little or no structural load and no code applies. Our broader all-position welding rod guide covers how position ratings translate across these situations.

A Simple Decision Rule

Run through this before you strike the arc:

• Structural, code-bound, thick material, groove weld? Vertical-up, 7018, no exceptions unless the WPS says otherwise.
• Pipe or heavy plate with an open root? Follow the procedure: often 6010 down for the root, 7018 up for everything after.
• Thin sheet, non-critical, cosmetic? Downhill 7018 at reduced amperage is a reasonable trade of penetration for control.
• Unsure what the joint needs? Default uphill, then inspect your own bead before the next pass. Direction is free to change on the next layer; a rejected weld is not.

Pick uphill when the joint has to hold. Save downhill for when the metal is thin, the load is light, and the procedure allows it. That single habit removes most of the mystery welders complain about with vertical 7018.

Common Vertical 7018 Defects and How to Fix Them

Gravity never stops working against a vertical-up 7018 puddle, and even steady hands produce discontinuities that can fail a bend test or visual inspection. Nearly every one traces back to a small change in technique, heat input, or preparation. Here are the defects you will meet most often and the adjustment that clears them.

Undercut at the Toes

Undercut is a groove melted into the base metal at the edge of the weld, leaving a weakened transition.

• Cause: Pausing too briefly at the side, an arc that is too hot, or travel speed that never lets the toe fuse.
• Visual Symptom: A sharp, sunken line along one or both toes with little or no filler metal in it.
• Corrective Adjustment: Widen the dwell at the toe instead of speeding up, hold a tight arc, and drop amperage in small steps if the puddle is washing out. The rhythm drilled in an Aluminium Welding Course builds exactly this kind of control.

Sagging/Overlap on the Underside

Sagging or overlap is molten metal rolling down the face of the previous bead, leaving lack of fusion under the rollover.

• Cause: Too much heat input, too wide a weave, or travel too slow for the amperage used.
• Visual Symptom: A rounded, lumpy overhang on the bottom of a vertical fillet with a visible poor tie-in line.
• Corrective Adjustment: Cut amps, narrow the weave, and stack each bead onto the solidified shelf rather than letting it flow down. The freeze behavior is why this electrode is a go-to All Position Welding Rod.

Trapped Slag Lines

Trapped slag is one of the most common reasons a 3G bend test fails, creating a glassy plane of weakness inside the weld.

• Cause: Slag left on a prior pass, or a weave that closed over the previous bead’s edge before the slag could float out.
• Visual Symptom: A continuous shiny line between passes or a void exposed in macroetch, heavily scrutinized under AWS visual acceptance criteria.
• Corrective Adjustment: Chip and wire brush every pass before the next, and keep the weave tight so the puddle never rolls over a sharp, unclean edge. Prep begins long before the arc, which is why guides like Aluminum Cleaner for Welding stress cleanliness for any process.

Porosity

Porosity is scattered gas pockets in the bead. Low-hydrogen rods make shielding disruption preventable with correct handling.

• Cause: Long arc length, moisture in the electrode, or drafts disrupting shielding.
• Visual Symptom: Tiny pinholes or clustered pits on the surface, a defect covered by OSHA’s welding and hot work guidelines.
• Corrective Adjustment: Keep a tight arc with correct work and travel angles, store rods in a rod oven per manufacturer guidance as recommended by Lincoln Electric, shield the area from wind, and avoid wide weaving that exposes the puddle. These steps also align with NIOSH fume and exposure best practices.

Cold Lap

Cold lap is filler that never fuses to the base metal or previous pass, simply resting on top of it.

• Cause: Insufficient heat, wrong work angle, or travel too fast to wet out the surface.
• Visual Symptom: A smooth rolled edge with a distinct line separating bead from plate, usually at the toe.
• Corrective Adjustment: Raise amperage slightly within the vertical range for that rod and pause at the toes for tie-in. For structural work, ANSI fabrication standards spell out the acceptance criteria.

Uneven Width

Inconsistent bead width looks sloppy and invites secondary problems like undercut or thin reinforcement.

• Cause: Inconsistent travel speed, unsteady hand placement, or an erratic weave moving vertically.
• Visual Symptom: The bead narrows and widens sporadically down its length.
• Corrective Adjustment: Lock in body positioning, settle into one rhythm, and repeat the same weave until it is automatic. Precision habits borrowed from Aerospace Welding material help here.

Burn-Through

Burn-through is a hole melted completely through the base metal, mostly on thinner stock.

• Cause: Excessive amperage, dwelling too long in one spot, or plate too thin for the rod diameter.
• Visual Symptom: A visible hole, heavy drop-through, or a concave backside with metal loss.
• Corrective Adjustment: Run amps at the low end of the vertical range, step down to a smaller electrode, and shorten dwell time. Heat control is just as critical in thin-section repairs like those in Alloy Wheel Welding: A Comprehensive Guide to Safe and Effective Aluminum Wheel Repair.

Multi-Pass Vertical Fillets: Interpass, Pass Sequence and Sizing

Single-bead vertical work is where you learn the technique. Structural work is where you prove it, and almost none of it fits in one bead. A 1/4-inch vertical fillet, a 3/4-inch groove, a column splice on a job site gets built one pass at a time. The pass that fails inspection is rarely the root. It is the fill passes stacked on top of it.

Multi-pass vertical 7018 is a logistics problem: where each bead goes, how hot the joint is allowed to get between beads, and when to stop and chip slag before you bury a defect under three more layers.

Planning the Pass Sequence

Every multi-pass vertical fillet follows the same anatomy: a root pass for penetration at the joint interior, fill passes to build the cross-section, and a cap for the finished profile. The common shop-built uphill sequence:

• Root pass: run tight and nearly stringer-like, fused into both plates at the joint interior. This is the foundation. If it is undercut or cold, everything above inherits the problem.
• Fill passes: stacked progressively, each fused to the solidified bead below and to one base metal face. A common pattern is a zigzag: one bead hugging the left of the root, the next the right, widening upward.
• Cap pass: slightly wider, producing a smooth, slightly convex profile with toes that blend out rather than step off abruptly.

Rule of thumb: a single vertical bead builds a leg roughly the electrode diameter plus a little more. A 3/16-inch 7018 gives you a 3/16- to 1/4-inch leg per pass, so a 1/2-inch fillet takes four to six passes depending on weave width and how aggressively you stack. These are working estimates, not code values. The finished leg is what gets measured with a fillet gauge, and it is always acceptable to add a pass rather than force an oversized one.

Bead placement matters more than bead count. Crowding the toes produces overlap and a cold, unfused edge where the bead piled up instead of wetting out. Crowding the center gives a narrow, high crown with incomplete side fusion: the weld looks substantial on the surface but has no throat. Aim each bead so it sits half on the previous bead and half on the plate, and point the rod slightly toward the face you want more metal on.

Interpass Temperature and Preheat

Interpass temperature is the variable beginners ignore and inspectors check. Every pass reheats the bead below it and the surrounding heat-affected zone, and stacking into an already hot joint means coarse grain structure, reduced toughness, and, with low-hydrogen electrodes, less benefit from the coating’s protection. Consumable manufacturers Lincoln Electric and Miller publish guidance that the maximum interpass temperature for carbon steel 7018 work typically falls around 500 to 700°F, with lower ceilings on higher-strength and alloy steels.

AWS D1.1 approaches this through the preheat table (Table 5.8): minimum preheat is driven by material thickness and hydrogen level, and where preheat is required, the interpass ceiling is managed with it as part of the written procedure. The practical field version: keep a temp stick or infrared thermometer at the station, check the plate between passes, and let the joint cool before continuing if you are near the ceiling. Welding alloy or higher-strength plate tightens electrode selection and preheat discipline considerably, and the Alloy Steel Welding Electrodes guide covers that selection logic in more depth.

Weave Width Limits and Stringers

Vertical weaves are convenient, but they are not unlimited. AWS D1.1 restricts weave width in many conditions: the code generally limits a weave pass to about 2.5 times the electrode diameter, and some procedures restrict weaves entirely in the root or critical passes of groove welds in favor of stringer beads. With a 3/16-inch rod, 2.5 diameters puts you near a 9/16-inch maximum. Past that, the puddle outruns the arc at the toes, the center freezes last, and you invite sagging and trapped slag.

Stringers also keep heat input lower per unit of deposited metal and are easier to place precisely on vertical geometry. Where the procedure allows weaves, use short, controlled side-to-side motion with a distinct pause at each toe, not a wide, fast serpentine that merely looks tidy.

Checking Workmanship Before You Proceed

Before each new layer, stop and read the last one. Check the toes for undercut or overlap, look for a continuous slag line that lifts off in one piece, and confirm the bead is convex rather than humped. If a pass is lumpy, uneven, or has a suspicious dark line along an edge, grind it out now. Covering a bad fill pass with a good cap is the most expensive way to fail a weld test, because the defect comes back out with a torch and a grinder after the whole joint is finished.

The rhythm that works: weld, chip, brush, inspect, measure temperature, then weld the next pass.

Testing, Inspection and Real-World Scenarios for Vertical 7018

Technique drills build skill, but vertical 7018 work only becomes real when someone else judges the result, whether that judge is a certified welding inspector, a quality shop, or a structural engineer on site. The criteria are surprisingly consistent. Understanding how vertical welds are tested lets you practice the right things instead of guessing.

What the AWS 3G Qualification Plate Actually Tests

The most common stick qualification in the United States is the AWS 3G plate test: a groove weld in the vertical position, typically a single-V groove with a backing bar or a specified root opening. E7018 run uphill is one of the most frequently chosen test conditions, because it mirrors what structural shops actually demand. A 4G test is the same idea in the overhead position, and many welders qualify on both so their certification covers more work. The American Welding Society publishes the qualification standards that define these test setups and the performance ranges a welder must stay inside.

What the plate really probes is consistency under gravity: root penetration on the first pass, sidewall fusion in the fill, and a cap free of trapped slag and undercut. A coupon is usually rejected for workmanship long before anyone worries about tensile strength.

How Vertical Welds Are Judged

Three inspection methods dominate, and each catches different problems:

• Visual inspection (VT) comes first. The inspector checks weld width consistency, profile, overlap, visible porosity, and undercut. A common acceptance limit caps undercut at roughly 1/32 inch (about 0.8 mm), with some standards citing 0.030 inch, while reinforcement must stay within a specified height range rather than being “as thick as possible.”
• Transverse bend tests slice the coupon and stretch the weld face, root, or sides. Cracks reveal lack of fusion, brittle regions, or trapped slag that visual inspection missed.
• Quarter-section macroetch is the shop and classroom favorite for vertical caps: the coupon is cut, polished, and etched so each layer shows in cross-section. It makes a slag line or an unfused sidewall corridor immediately obvious, which is exactly why it works so well on multi-pass vertical work.

Certified welders must requalify whenever the process, position, material group, or thickness range moves outside the limits recorded on their qualification. That is why a welder certified in flat and horizontal plate work cannot walk onto a column job and weld vertical 7018 without a new test.

Where Vertical 7018 Shows Up on the Job

Real work rarely looks like a test coupon, but the same skills transfer directly:

• Structural columns and beams — fillet welds joining base plates, stiffeners, and clip angles, often in the flat-cheat position but frequently vertical when the member can’t be turned.
• Pipe and tube — 5G and 2G pipe positions add a fixed-root challenge; vertical progress along the side wall is the same uphill weave logic, only curved.
• Machine frame and equipment repair — cracked housings, gearbox frames, and press structures bolted in place, where the only reachable approach is straight up a vertical crack.
• Field retrofits and plant maintenance — brackets and supports welded to existing columns where grinding the assembly flat isn’t an option.

The self-check is always the same three questions: Is the bead width even from bottom to top? Are the toes tied in with no visible line of shadow? Did the slag come off in one piece and leave a clean, uniform ripple pattern behind?

Mild Steel Versus Harder-to-Weld Materials

E7018 on mild steel is forgiving: puddle fluidity is high, the slag releases cleanly, and a slightly wide weave is tolerated. Move to higher-carbon or alloy steel materials and two things change. First, preheat and interpass temperature control become mandatory to avoid hydrogen cracking, which stays invisible until hours after welding. Second, the puddle behaves differently, tighter and less forgiving of long arcs, so travel speed and arc length matter more than they do on mild steel.

High-strength and quenched-and-tempered steels also shrink your heat input window. Too hot and you soften the heat-affected zone; too cold and you risk cold lap and hydrogen pickup. When the material isn’t mild steel, the vertical procedure should come from a written specification, not from habit.

Build Your Own Self-Check Routine

Between formal tests, welders stay sharp by inspecting their own coupons the way an inspector would. Cut a vertical fillet in half, etch it with a mild etchant, and study the pass stacking. Photograph each run from the same angle so width changes show up, and log amperage, rod diameter, and travel speed beside the photo. Over a dozen coupons, patterns emerge fast, and the flaws you keep repeating are exactly what a test plate or procedure guide from a major manufacturer will help you correct.

Validation isn’t a separate skill from welding; it’s the feedback loop that turns practice into pay raises. Test on purpose, inspect honestly, and the next vertical 7018 run will be judged long before anyone else sees it.

Practice Drills, Safety Notes and Key Takeaways for Mastering Vertical 7018

Every technique in this guide only becomes yours after you repeat it under real conditions. Vertical 7018 is a hands skill, not a reading skill. The good news is that you can train it cheaply, in short sessions, with a handful of scrap coupons and a methodical approach.

A Practice Plan That Actually Builds Skill

Start by cutting 8- or 10-inch coupons from 1/2-inch plate. That thickness forgives a few mistakes without hiding them, and the short length lets you run several beads in one session without burning through your scrap pile. Tack two coupons into a simple T joint and work through these drills in order:

1. Root-only vertical fillets (20 beads). Run nothing but the first pass, uphill, stopping at the top of each coupon. Twenty consecutive roots before you even attempt a capped weld. This is where arc length, puddle read and toe pausing become automatic.
2. Weave control (10 beads). Same joint, but now add the triangle or shelf weave, concentrating on pausing at each toe and stacking the puddle on the previously solidified shelf.
3. Full multi-pass capped fillets (10 beads). Root, fill and cap, with interpass temperature checks between passes, sizing each layer so every bead fuses to two surfaces.
4. Restarts and tie-ins (10 beads). Stop mid-run, chip the crater, then restart 1/2 inch behind the tie-in and blend forward. Real work is mostly restarts.

The single most useful progression rule: fix one variable at a time. Change amps, weave width, pause or travel speed, then weld a bead before changing anything else. If you adjust two things at once, you learn nothing from the result.

A Pre-Run Checklist Worth Printing

• Rod pulled from the oven or sealed container within its exposure window; no damp or frosty coating (All Position Welding Rod Guide: Types, Uses & Tips covers rod handling across positions).
• Amps set for the diameter and the vertical-up position, polarity confirmed (DC+ for most 7018 work).
• Joint ground clean at the root, root opening and root face within spec, tacks secure.
• Work clamp within a foot of the joint, PPE on, ventilation running, fire watch clear.
• Interpass temperature checked before the next layer goes on.

Safety Notes Specific to Vertical Work

Vertical-up puts the puddle directly below your face, which means slag and spatter fall toward the operator. A standard shade 10–13 filter lens is typical for stick welding, but a helmet alone is not enough: wear a leather collar or jacket with the collar up, gloves with no cuffs that catch falling slag, and never raise your hood under overhead work without checking what is still glowing above you.

Fumes deserve the same respect. The OSHA construction standard 1926.353 and general industry 1910.252 require adequate ventilation and, in confined or poorly ventilated work, air-supplied respirators, with exposure enforced through permissible exposure limits. The NIOSH welding safety topic page is a solid starting point for fume hazards, and low-hydrogen rods add one more rule: handle hot rods with dry gloves and keep unused electrodes in a rod oven or sealed quiver.

Key Takeaways

• Weld 7018 vertical uphill unless a written procedure explicitly calls for downhill, and run a tight arc throughout.
• Start slightly below the flat-position amp range, pause at each toe, and stack the weave on the solidified shelf.
• Read the puddle, not the arc: a shiny, fluid, evenly edged pool means you are on track.
• Train in 8- or 10-inch 1/2-inch coupons, root-only first, one variable changed per bead.
• Keep rods dry, keep the joint clean, and keep fumes and falling slag accounted for before you strike an arc.

Vertical 7018 rewards patience more than talent. Run twenty roots, film a few, change one thing at a time, and the position stops being a test and becomes routine. If you want the broader picture of why this process still anchors the field, our look at the advantages of stick welding explains where SMAW keeps beating newer processes.

Frequently Asked Questions

What amps should I use for 7018 vertical up?

Start about 10–20% below your flat setting: roughly 75–100 A for 1/8-inch and 90–120 A for 5/32-inch. Adjust based on puddle behavior — if the puddle is too fluid and sagging, drop 5–10 A; if it won’t wet the toes, raise slightly.

Should 7018 be welded vertical up or vertical down?

Uphill is the standard for low-hydrogen rods and structural work because it gives deeper penetration and better slag control. Downhill travels too fast for 7018, causing shallow penetration and slag inclusions, and is only used under a qualified procedure — often as a 6010 root with 7018 fill and cap.

What rod size is best for vertical 7018?

1/8-inch is the most controllable for vertical uphill, with 5/32-inch acceptable for experienced welders on heavier sections. Rods of 3/16-inch and larger deposit metal faster than most welders can control against gravity.

Why is my 7018 vertical weld sagging or dripping?

Usually too much heat or a weave that is too wide. Reduce amperage, narrow the weave to about 2.5–3 electrode diameters, and increase travel speed slightly. Also check arc length — a long arc adds heat without useful shielding.

Why do I get trapped slag in a vertical 7018 cap?

Slag left in a groove or between beads gets covered by the next pass. Chipping and wire-brushing each pass thoroughly, and weaving consistently so the puddle washes the previous bead’s edge, prevents the glassy slag lines that show up in bend tests.

Does 7018 need a rod oven for vertical structural work?

For code work, yes — low-hydrogen electrodes absorb moisture from humid air, and hydrogen is a leading cause of cracking. Keep opened packages in a controlled-storage oven and limit ambient exposure to the manufacturer’s stated time, rebaking when exceeded.

What angle should the rod be held at for vertical 7018?

Work angle stays near 45 degrees in a fillet corner, and travel angle uses a slight drag of about 5–15 degrees, with the rod pointed slightly up into the puddle so the arc force supports the molten metal.

Is 7018 vertical uphill required for structural certification?

It is the most common test condition for the AWS 3G plate qualification, and AWS D1.1 permits downhill only under qualified procedures. Check the specific WPS for preheat, pass technique, and weave limits before starting.