Tag: 7018 rod storage

Stick Welding Porosity Troubleshooting: Pinholes, Wormholes, Moisture, Arc Length, and Electrode Checks

Stick welding porosity usually comes from gas trapped in the weld metal before the puddle freezes. With SMAW, start with the electrode, base metal, arc length, amperage, polarity, and technique before blaming the welder. Pinholes after slag removal, wormholes in the bead, rough starts, popping arc behavior, and scattered pits usually point to moisture, contamination, long arc length, wrong rod handling, or welding over paint, oil, rust, zinc, primer, or damp steel.

The repair path is simple: stop welding, identify whether the porosity is surface-only or through the bead, clean the joint to bright metal, switch to known-good electrodes, shorten the arc, verify amperage and polarity, and run a controlled test bead on clean scrap. For low-hydrogen rods, especially 7018, porosity must be treated as a storage and hydrogen-control issue, not only a bead appearance problem. See the related WSP guide on 7018 rod moisture contamination when damp rods, sticking, or cracking risk are present.

Common Symptoms

Symptom	Likely Cause	First Check
Small pinholes after chipping slag	Moisture, contamination, or long arc	Try dry rods on clean scrap
Wormholes or tunnels in bead	Severe contamination or trapped gas	Grind out and clean joint
Porosity starts after rod change	Bad rod batch, damp coating, wrong rod storage	Compare against sealed rods
Porosity only at starts	Poor restart, long arc, damp rod tip	Clip/restrike properly and shorten arc
Porosity on rusty or painted steel	Surface contamination burning into puddle	Remove coating and re-test
Porosity with 7018 plus sticking	Low amperage, damp coating, bad arc length	Check storage and amperage

Likely Causes

Moisture in electrodes: Damp coating can release hydrogen and other gases into the weld pool. Low-hydrogen electrodes are especially sensitive. Opened 7018 should be stored according to the electrode manufacturer, code, and WPS requirements.

Dirty base metal: Oil, grease, paint, primer, rust, mill scale, cutting fluid, galvanized coating, and moisture can create gas pockets when heated. Stick welding is more tolerant than TIG or MIG, but it is not immune to contamination.

Long arc length: A long arc can reduce shielding from the electrode coating and pull air into the arc zone. This is common with new operators trying to see the puddle.

Wrong rod manipulation: Excessive whipping with low-hydrogen rods can cause porosity. Some cellulose rods tolerate whip-and-pause technique, but 7018 should normally be run with a short, steady arc.

Wrong amperage or polarity: Too-low amperage can leave a cold, sluggish puddle that traps gas. Wrong polarity can create instability, spatter, poor penetration, and porous starts. If the symptom includes sticking, review 7018 rod sticking causes and solutions.

Quick Checks

Use fresh, known-good electrodes from sealed or properly stored packaging.
Clean the weld area to bright metal at least 1/2 in beyond the weld zone.
Remove oil, paint, primer, zinc, moisture, rust, and grinding dust before welding.
Shorten the arc until the puddle is controlled and the arc sounds steady.
Verify polarity: 6010 commonly requires DCEP, while many 7018 rods run on AC or DCEP depending on formulation.
Check amperage against the rod diameter, position, and manufacturer chart.
Run one test bead on clean scrap with one change at a time.

Root Cause Analysis

If porosity disappears on clean scrap with fresh rods, the welder is probably not the root cause. The problem is usually the workpiece surface, electrode condition, or joint environment. If porosity follows one rod container but not another, quarantine the suspect rods. If porosity appears only in vertical or overhead work, look at arc length, travel speed, rod angle, and slag control.

For rod selection, the difference between cellulose and low-hydrogen electrodes matters. WSP’s 6010 vs 7018 guide explains that 6010 is used for digging penetration and root work, while 7018 is used for low-hydrogen structural welds. Do not store or run them the same way. Mixing 6010 and 7018 in the same oven or job box can create wrong-rod and wrong-storage problems.

Inspection Steps

Chip and wire-brush the weld. Confirm whether holes are isolated surface pits or continuous porosity.
Grind one defect open. If holes continue below the surface, remove the weld until sound metal is reached.
Inspect rod coating. Reject rods with cracked, swollen, oily, soft, rusty, chipped, or wet coating.
Check base metal. Look for paint, oil, water, galvanizing, primer, heavy rust, cutting fluid, and laminations.
Check machine setup. Confirm amperage, polarity, lead connections, work clamp contact, and cable condition.
Check technique. Look for long arc, excessive weave, whipping with low-hydrogen rods, or travel speed too fast for gas escape.
Make a comparison weld using clean scrap and fresh rods. If the test is sound, return to the workpiece and correct cleaning or joint conditions.

Test Procedures

Use a clean scrap coupon of the same material when possible. Run three beads: one with the suspect rod, one with a fresh rod from sealed storage, and one after changing arc length and amperage. Keep polarity, rod diameter, and base metal consistent. If only the suspect rod creates porosity, remove that rod batch from critical work. If all beads are porous, inspect work clamp contact, machine output, arc length, and surface preparation.

For 7018, test beads are not proof of low-hydrogen compliance. A rod can make an acceptable-looking bead and still be unacceptable for code, pressure, structural, lifting, or restrained work if exposure history is unknown. Follow the WPS, inspector, electrode manufacturer, or engineer requirement.

Visual Wear Indicators

Electrode coating cracks: moisture cycling, impact damage, or old stock.
Soft or powdery coating: moisture damage; do not use for critical welds.
Rust on exposed core wire: storage failure or aged rods.
Oily rod surface: contamination that can create porosity and fumes.
Blackened start pits: poor restart, contamination, or arc instability.
Glassy irregular slag on 7018: possible damp coating or incorrect settings.

Compatibility Notes

Verify electrode classification, rod diameter, polarity, amperage range, base metal, position, and storage requirement before ordering or welding. E6010, E6011, E7014, E7018, E7018-1, E7018AC, stainless electrodes, nickel cast-iron rods, and hardfacing electrodes do not share the same storage, polarity, or technique rules. When the rod is unknown, label it Unknown (Verify) and do not use it on critical welds.

What To Verify Before Ordering

Exact electrode class and brand required by the WPS or repair procedure.
Rod diameter that matches material thickness, position, and available amperage.
Machine output and polarity compatibility.
Whether 7018AC is required for an AC-only transformer machine.
Whether low-hydrogen storage, sealed cans, rod oven, or quiver control is required.
Base metal condition: clean mild steel, rusty repair work, galvanized, coated, cast iron, hardfacing, or unknown alloy.

Common Wrong-Part Mistakes

Using old open 7018 from a toolbox on a structural repair.
Buying standard 7018 for a machine that only runs AC poorly.
Using 6010 because it burns through contamination instead of cleaning the joint.
Running a specialty electrode like nickel or hardfacing without checking polarity and procedure.
Assuming porosity is always caused by amperage when the rod is damp or the base metal is contaminated.

Field Fix vs Proper Fix

Condition	Field Fix	Proper Fix
Pinholes with 7018	Try fresh dry rods on clean scrap	Correct rod storage and follow WPS exposure limits
Porosity over paint or rust	Grind test area clean	Remove coating from full weld zone before welding
Long arc porosity	Shorten arc and reduce travel speed	Retrain technique and verify settings
Damp rods in the field	Use sealed fresh rods for noncritical testing	Use approved oven/quiver procedure or discard
Wormholes in finished weld	Stop and mark defect	Grind out to sound metal and reweld under corrected conditions

Related Failure Paths

Porosity often travels with rod sticking, slag inclusions, lack of fusion, undercut, arc blow, cracking, and failed visual inspection. A bad ground or unstable arc can make the operator hold a longer arc, which then creates porosity. Damp 7018 can create porosity and increase hydrogen-cracking risk. Poor fume control is also common when welding dirty, coated, or contaminated steel; review welding fume extractor troubleshooting when smoke is not being captured at the arc.

Safety Notes

Do not weld over unknown coatings, paint, solvent residue, oil, galvanized coating, plating, or contaminated steel without identifying the hazard. Use ventilation, fume extraction, correct helmet shade, dry gloves, fire watch, and electrical safety practices. Keep your head out of the plume. Do not use wet rods, improvised rod heating, torch-baked electrodes, microwave drying, or truck-dash drying for low-hydrogen work.

Sources Checked

Washington Alloy electrode catalog sections on 6010, 7018, low-hydrogen welding tips, and porosity warnings related to whipping low-hydrogen electrodes.
Lincoln Electric consumables storage and handling guidance for covered electrodes and moisture-resistant packaging.
Weld Support Parts stick welding support articles on 7018 moisture contamination, 7018 sticking, 6010 vs 7018 selection, and fume extraction troubleshooting.

May 19, 2026

6010 vs 7018 Rod Selection Guide: When to Use Each Stick Electrode

Use 6010 when the weld needs deep penetration, fast-freeze puddle control, open-root tie-in, or tolerance for less-than-perfect steel. Use 7018 when the weld needs low-hydrogen deposit control, higher tensile classification, smoother fill and cap passes, or structural weld quality on clean steel. The common field mistake is treating them as interchangeable. They are not. A 6010 root can solve lack-of-fusion problems that a soft 7018 arc may not reach. A 7018 fill or cap can reduce hydrogen-cracking risk where a cellulose rod is the wrong choice.

For a quick comparison, the existing Weld Support Parts article 6010 Electrode vs 7018 Electrode: What Welders Need to Know covers the basic arc differences. This guide is focused on selection at the parts counter and in the field: base metal condition, machine output, polarity, joint type, code requirement, rod storage, and wrong-rod symptoms.

Fast Selection Rule

Job Condition	Choose 6010	Choose 7018
Open-root pipe or root pass	Best fit	Usually not first choice
Dirty, rusty, painted, or mill-scale steel	Better tolerance	Clean steel required
Structural fill and cap welds	Possible only if procedure allows	Preferred
Low-hydrogen requirement	No	Yes
Machine is AC-only	Wrong choice in most cases	Use 7018AC or AC-rated 7018
Need smooth bead appearance	Rougher, digging bead	Cleaner appearance
Vertical or overhead control	Strong fast-freeze control	Good with correct amperage and dry rods

What 6010 Does Better

6010 is a high-cellulose sodium SMAW electrode. Its value is arc force. The arc digs, the puddle freezes fast, and slag coverage is light compared with low-hydrogen rods. That makes 6010 useful for open roots, pipe roots, maintenance welds, and joints where penetration is the main concern. Weld Support Parts lists the Washington Alloy 6010 electrode as a high-cellulose sodium rod for deep penetration, fast-freezing puddles, and arc force, conforming to AWS A5.1 E6010 and ASME SFA 5.1 E6010.

Choose 6010 when the symptom is lack of root fusion, a cold root, poor tie-in at the land, or a root bead that will not keyhole. It is also the better rod when the base metal cannot be perfectly cleaned in field repair work. It does not replace cleaning, but it tolerates imperfect surfaces better than 7018.

What 7018 Does Better

7018 is an iron-powder, low-hydrogen SMAW electrode. It is selected for strength, crack resistance, smoother beads, and structural work where low hydrogen matters. The “70” indicates a 70 ksi tensile classification, the “1” indicates all-position capability, and the “8” indicates low-hydrogen iron-powder coating with AC or DC reverse polarity use depending on the specific product.

Choose 7018 when the weldment is structural, restrained, thick, high-strength, or subject to cracking concerns. Use it for fill and cap passes after a 6010 root where the procedure allows that sequence. For current selection on machines that do not run standard 7018 correctly, use the verified guide Should You Use AC or DC Current? When to Use 7018AC.

Common Symptoms When the Wrong Rod Is Used

7018 used where 6010 is needed: root bead sits cold, sidewall fusion is poor, arc will not dig through the joint, or slag traps appear at the root.
6010 used where 7018 is needed: bead profile is rough, hydrogen control is not acceptable, tensile classification may be below procedure, or cap appearance is poor.
Standard 6010 on the wrong machine: unstable arc, rod snuffing, arc outages, or inability to hold a keyhole.
Damp 7018: porosity, erratic starts, excess spatter, underbead cracking risk, and failed procedure control.

Inspection Steps Before Selecting Rod

Confirm the welding procedure or job requirement. Do not substitute 6010 for 7018 on code work unless the procedure permits it.
Check base metal condition. Rust, paint, heavy mill scale, and field contamination favor 6010 for penetration, but cleaning is still required.
Verify machine output. Standard 6010 normally needs DC electrode positive. 7018 may run DCEP or AC only if the rod is rated for it.
Confirm joint type. Open root and pipe root conditions often favor 6010. Structural fill, cap, and restrained welds often favor 7018.
Check rod storage. Opened 7018 must be handled as a low-hydrogen consumable. Do not treat it like 6010.

Test Procedures

Before committing to production welds, run a short test bead on matching scrap. With 6010, confirm arc force, keyhole control, root tie-in, and slag release. With 7018, confirm restart quality, slag peel, toe wet-out, and bead profile. If 7018 sticks immediately, review the troubleshooting path in 7018 Rod Sticking: Causes & Solutions before blaming the electrode.

For 1/8 in rods, many field settings fall near 75-125 amps for 6010 and around 90-140 amps for 7018, but the product data sheet and welding procedure control the final setting. Arc length should stay tight with both rods. Long arc length increases spatter, porosity risk, undercut, and poor bead control.

Visual Wear and Defect Indicators

6010 too cold: sticking, ropey bead, poor root wash, inconsistent keyhole.
6010 too hot: excessive burn-through, undercut, hard-to-control keyhole, thin root bead.
7018 too cold: high bead crown, slag inclusions, rod sticking, poor restart.
7018 too hot: undercut, excessive puddle fluidity, flat washed bead, poor vertical control.
Damp 7018: rough starts, porosity, arc instability, and higher cracking risk.

Compatibility Notes

Verify the rod against the base metal, welding procedure, machine output, polarity, position, and storage requirement. 6010 is not a low-hydrogen electrode. 7018 is not a deep-digging cellulose root rod. A machine that runs 7018 well may still run 6010 poorly if it does not support the required arc characteristics. A small AC transformer machine may require 7018AC instead of standard 7018.

Also verify the electrode holder and lead set. Overheated holders, loose jaws, undersized cable, and poor work clamp contact can mimic rod problems. For holder sizing and lead compatibility, use Welding Electrode Holder: Choose the Best for Stick Welding.

What To Verify Before Ordering

Electrode classification: E6010, E7018, E7018-1, E7018AC, or required low-alloy variant.
Rod diameter: match amperage range, joint size, position, and base metal thickness.
Polarity: DCEP, AC, or both depending on rod and machine.
Storage: low-hydrogen rods require dry storage control after opening.
Code requirement: AWS, ASME, customer WPS, or repair procedure.
Base metal: mild steel, low-alloy steel, pipe grade, weathering steel, or unknown steel.

Common Wrong-Part Mistakes

Ordering 6011 when the procedure calls for 6010 because both are cellulose rods.
Ordering standard 7018 for an AC-only machine instead of 7018AC.
Using 6010 for a low-hydrogen requirement because it penetrates better.
Using old opened 7018 from a shelf for critical welds.
Choosing rod diameter by habit instead of joint size, position, and amperage range.

Field Fix vs Proper Fix

A temporary field fix is to switch from 7018 to 6010 only when penetration or root control is the actual issue and the procedure allows it. Another temporary fix is to increase amperage slightly if 7018 is sticking. The proper fix is to match the electrode classification to the WPS, clean the joint, verify polarity, use dry low-hydrogen rods, and correct the ground path.

For 7018 storage, use a proper rod oven where required. The related Weld Support Parts rod oven guide YESWELDER BWX-01 Welding Rod Oven Review discusses portable electrode storage for E7018 and similar rods.

Related Failure Paths

Lack of fusion from soft arc or low amperage.
Hydrogen-assisted cracking from damp low-hydrogen electrodes.
Slag inclusion from incorrect rod angle or cold 7018 puddle.
Burn-through from excessive 6010 heat on open-root joints.
Arc instability from wrong polarity, poor ground, or incompatible machine output.

Safety Notes

SMAW produces arc radiation, fumes, hot slag, electrical shock hazards, and fire hazards. Use correct PPE, ventilation, dry gloves, proper work clamp contact, and approved electrode storage. Do not weld unknown coated, galvanized, painted, or contaminated material without identifying the coating and controlling fumes. Never substitute electrode class on load-bearing or pressure work without the welding procedure or engineer approval.

Bottom Line

6010 is the penetration and root-control rod. 7018 is the low-hydrogen structural rod. For pipe and open-root work, 6010 often starts the weld. For strength, fill, cap, and crack resistance, 7018 often finishes it. Selection should be based on WPS, polarity, base metal condition, storage control, and the failure you are trying to prevent.

May 19, 2026