If you have run MIG long enough to feel comfortable with it and then picked up a spool of flux-cored wire expecting a similar experience, you already know something is different. The arc sounds different. The bead looks different. And if you ran it on the same polarity as your MIG setup, you probably got a mess of porosity and spatter that made no sense given your experience level. The problem is not your machine. Flux-cored arc welding (FCAW) is a distinct welding process with its own rules, and what works for MIG will not work here.
This guide covers what FCAW is, why the self-shielded versus gas-shielded distinction matters more than any other single factor, and how to set up your equipment, select wire, and adjust your technique. If you are coming from MIG, expect to unlearn a few habits. If you are new to welding entirely, this article will give you a clear framework for understanding FCAW on its own terms. Either way, the organizing principle is simple: FCAW comes in two fundamentally different types, and choosing between them determines everything else.
What Is Flux-Cored Arc Welding (FCAW)?
Flux-cored arc welding is an arc welding process that uses a continuous tubular electrode filled with flux compounds. When the arc melts the wire, the flux core performs several functions at once. It generates shielding gas (in self-shielded types), produces slag that protects the solidifying weld metal, adds deoxidizers and alloying elements to the weld pool, and stabilizes the arc. This is fundamentally different from gas metal arc welding (GMAW, commonly called MIG), where a solid wire is used and all shielding comes from externally supplied gas.
AWS classifies FCAW as its own distinct process under standards A5.20 and A5.36. It is not a subclass of GMAW. The electrode is tubular rather than solid, the shielding mechanism is split between flux-generated and externally supplied gas depending on wire type, and the arc characteristics, polarity requirements, and technique are unique to FCAW. You may hear FCAW described informally as “MIG without gas.” That description applies only to one type of FCAW (self-shielded) and even then it is an oversimplification that misses the deeper differences in polarity, wire construction, slag system, and operating technique.
FCAW was developed in the 1950s as a higher-deposition alternative to shielded metal arc welding (stick welding) for heavy fabrication and outdoor use. It has since become a primary process in structural steel erection, shipbuilding, heavy equipment manufacturing, field repair, and construction. The reason for its adoption in these industries comes down to the two faces of the process: the ability to weld outdoors without gas bottles, and the ability to deposit metal at high rates with good mechanical properties.
What FCAW is not: It is not MIG with a different wire. It is not metal-cored arc welding (a GMAW process under AWS A5.18, not FCAW). And it is not simply stick welding with a continuous wire. FCAW sits in its own category with its own advantages, limitations, and best-use cases.
Self-Shielded vs Gas-Shielded FCAW: The Key Difference
The single most important concept in FCAW is the distinction between self-shielded (FCAW-S) and gas-shielded (FCAW-G) wire. Every other decision you make about polarity, equipment setup, wire selection, and technique depends on which type you are running. If you understand nothing else about FCAW, understand this difference.
Self-Shielded Flux-Cored Arc Welding (FCAW-S)
Self-shielded FCAW uses a flux core formulated to generate its own shielding gas when the flux compounds decompose in the arc. The flux also produces slag that covers and protects the weld bead after the arc passes. No external shielding gas cylinder, regulator, or hose is required. You connect the work clamp, set the correct polarity (typically DC electrode negative, DCEN), and weld.
This makes FCAW-S highly portable and ideal for outdoor and field work. Structural steel erectors, field repair crews, and construction welders rely on self-shielded wire because it tolerates wind and drafts that would disrupt gas-shielded processes. Common self-shielded wire classes include E71T-8 (low-hydrogen, high-impact, used in structural code work), E71T-11 (general purpose, moderately forgiving), and E71T-GS (single-pass only, commonly used for thin metal and light repair). Each has different technique requirements and application limits.
A critical caveat: self-shielded is wind-tolerant but not wind-proof. Heavy wind (generally above 15 mph) can still disrupt the gas envelope generated by the flux. Wind screens are recommended for sustained outdoor work even with self-shielded wire.
Gas-Shielded Flux-Cored Arc Welding (FCAW-G)
Gas-shielded FCAW uses a flux core designed primarily for slag formation, deoxidation, and alloying. The flux alone does not generate enough shielding gas to protect the weld pool. External shielding gas (typically CO2 or argon/CO2 blends, similar to MIG) is required. The flux and the gas work together: the gas handles atmospheric shielding, while the flux handles slag coverage and weld metal chemistry.
FCAW-G typically runs on DC electrode positive (DCEP, DC+) and uses a shorter stickout than self-shielded wire. It generally produces less spatter than FCAW-S, a cleaner bead appearance, and slag that is often self-peeling or easy to remove. Common gas-shielded wire classes include E71T-1 (general purpose, all position), E71T-9 (improved impact properties for low-temperature service), and E71T-12 (low-hydrogen, structural code work).
Because it requires external shielding gas, FCAW-G is primarily an indoor shop process. It is common in production fabrication, shipbuilding, and heavy manufacturing where high deposition rates and good bead appearance are priorities.
Self-Shielded vs Gas-Shielded Comparison Table
| Feature | Self-Shielded (FCAW-S) | Gas-Shielded (FCAW-G) |
|---|---|---|
| External shielding gas | Not required | Required (CO2 or Ar/CO2 blend) |
| Typical polarity | DC electrode negative (DCEN) | DC electrode positive (DCEP) |
| Typical stickout | 3/4″ to 1-1/4″ (19-32mm) | 1/2″ to 3/4″ (13-19mm) |
| Wind tolerance | High (usable outdoors in wind) | Low (similar to MIG) |
| Fume generation | Higher | Moderate |
| Spatter level | Generally higher | Moderate |
| Slag characteristics | Can be heavy, may need chipping | Usually lighter, often self-peeling |
| Typical wire classes | E71T-8, E71T-11, E71T-GS, E71T-14 | E71T-1, E71T-9, E71T-12, E71T-5 |
| Common applications | Field/outdoor, structural steel, repair, maintenance | Indoor production, shipbuilding, heavy fabrication |
| Deposition rate | Moderate | Moderate to high |
| Machine requirements | Polarity switchable to DCEN; self-shielded wire | Polarity switchable to DCEP; gas supply system |
Why does the distinction matter so much? Because choosing FCAW-S versus FCAW-G determines your machine polarity, drive roll and contact tip requirements, shielding approach, technique adjustments, and application compatibility. Using a gas-shielded wire outdoors without wind protection will likely produce porosity. Running self-shielded wire on DCEP (as if it were MIG) will produce a porous, spattery mess and may damage your wire feeder. The wire class tells you which type you have, and the wire class is printed on the spool. Read it before you set up.
Equipment Requirements for FCAW
Setting up for FCAW requires some adjustments from MIG. The machine, wire feeder, and consumables are largely the same hardware, but the configuration differs in critical ways.
Polarity: The Non-Negotiable Difference
Polarity is the most common setup error in FCAW and the one most likely to ruin your results. The rule is simple but not universal across all wire types:
- Self-shielded FCAW (FCAW-S): Requires DC electrode negative (DCEN, also marked DC- on many machines). The flux chemistry in self-shielded wire is formulated for negative polarity.
- Gas-shielded FCAW (FCAW-G): Requires DC electrode positive (DCEP, DC+). The combination of flux chemistry and external shielding gas requires positive polarity.
Using the wrong polarity with either wire type causes porosity (inadequate gas coverage), poor fusion, excessive spatter, and erratic arc behavior. Some welders have damaged wire feeders by running self-shielded wire on DCEP for extended periods.
Not all MIG machines allow easy polarity switching. Some entry-level machines come wired for DCEP only (MIG polarity) and require internal rewiring or a polarity reversal kit to run DCEN. Check your machine’s manual before assuming it can handle FCAW-S.
Wire Feeder Setup: Drive Rolls, Liners, and Contact Tips
FCAW wire is tubular and softer than solid MIG wire. It requires different handling through the wire feeder.
Drive rolls: Flux-cored wire can be deformed by smooth V-groove rolls designed for solid wire. Use drive rolls specifically for flux-cored wire. Some manufacturers recommend V-groove rolls for FCAW, others recommend knurled rolls (especially for self-shielded wire, which needs better grip). There is no universal answer. Check the recommendation for your specific wire and feeder.
Feed head tension: Less tension than MIG. Overtightening deforms the tubular wire, causing feeding problems and an inconsistent arc. Set tension just enough to feed without slipping.
Liners: Standard steel liners usually work for steel flux-cored wire, but the liner must be clean and sized correctly for the wire diameter. Wire debris buildup in liners causes erratic feed. Unlike aluminum MIG wire, FCAW does not require Teflon or nylon liners.
Contact tips: FCAW wire is slightly larger than its nominal diameter because of the tubular construction. Use contact tips sized for flux-cored wire. The bore in an FCAW contact tip is typically 0.005 to 0.010 inches larger than a solid-wire tip of the same nominal size. Standard solid-wire contact tips may cause burnback or erratic feeding with FCAW wire. Some manufacturers offer FCAW-specific tip sizes.
Welding Machine Capabilities
FCAW requires a constant voltage (CV) power source, same as MIG. Most MIG machines can run FCAW if they can switch polarity.
Entry-level 120-volt MIG machines often run FCAW-S effectively, especially with E71T-GS. This is a common entry point for hobbyists who want to weld outdoors without buying gas. Industrial FCAW-G and larger-diameter FCAW-S (such as 5/64-inch E71T-8) require 240-volt or three-phase power and higher-duty-cycle machines.
If you are setting up your machine for FCAW, check three things before you start: polarity (is the machine wired correctly for your wire type?), drive rolls (are they appropriate for flux-cored wire?), and contact tip (is it sized for flux-cored wire?). A setup checklist helps catch the common oversights.
Polarity and Settings Starting Points
FCAW settings are not interchangeable with MIG settings. Wire feed speed (WFS) and voltage relationships differ because flux-cored wire has different current-carrying characteristics, a different deposition rate per amperage, and different arc behavior. Even for the same material thickness, FCAW typically uses different voltage and wire feed speed ranges than MIG.
Polarity by Wire Class
The table below summarizes typical polarity for common FCAW wire classes. This is a starting reference. Always verify polarity on the manufacturer data sheet for the specific wire you are using. Some dual-rated wires and newer classifications under AWS A5.36 may have different requirements.
- FCAW-S (self-shielded, DCEN): E71T-8, E71T-11, E71T-GS, E71T-14
- FCAW-G (gas-shielded, DCEP): E71T-1, E71T-9, E71T-12, E71T-5
Settings Starting Point Table
All values in the table below are typical starting ranges compiled from multiple manufacturer data sheets. They are not optimized for any specific product. Actual settings depend on material thickness, joint configuration, welding position, and operator technique. For code work, a qualified welding procedure specification (WPS) takes precedence.
| Wire Class | Type | Wire Dia. | Material Thickness | Amperage Range | WFS Range (ipm) | Voltage Range | Polarity |
|---|---|---|---|---|---|---|---|
| E71T-GS | SS | 0.035″ (0.9mm) | 1/8″ (3mm) | 100-150A | 200-350 | 15-18V | DCEN |
| E71T-11 | SS | 0.045″ (1.2mm) | 1/4″ (6mm) | 140-200A | 180-300 | 17-20V | DCEN |
| E71T-8 | SS | 5/64″ (2.0mm) | 1/2″ (12mm) | 200-350A | 90-180 | 20-28V | DCEN |
| E71T-1 | GS | 0.035″ (0.9mm) | 1/8″ (3mm) | 100-160A | 250-400 | 22-26V | DCEP |
| E71T-1 | GS | 0.045″ (1.2mm) | 1/4″ (6mm) | 150-250A | 250-450 | 24-28V | DCEP |
| E71T-9 | GS | 0.045″ (1.2mm) | 1/4″ (6mm) | 150-230A | 230-400 | 24-28V | DCEP |
| E71T-12 | GS | 0.045″ (1.2mm) | 1/4″ (6mm) | 150-230A | 230-400 | 24-28V | DCEP |
SS = Self-shielded, GS = Gas-shielded. All values are starting points only. Always consult the specific wire manufacturer’s data sheet for recommended settings before welding.
Why Settings Differ Between FCAW and MIG
If you are used to MIG, the FCAW settings table may look unfamiliar. Several factors explain the differences:
- Flux-cored wire has higher electrical resistance than solid wire of the same diameter, which affects the current draw at a given wire feed speed.
- The flux core affects arc stability and metal transfer mode. FCAW typically operates in a globular-to-spray transfer, not the short-circuit or spray transfer familiar from MIG.
- Deposition rate per amperage is generally higher for flux-cored wire than for solid wire.
- Different polarity (DCEN for FCAW-S, DCEP for FCAW-G) means the same wire feed speed and voltage produce completely different results.
Do not attempt to convert MIG settings to FCAW. Start with the manufacturer’s recommended range and tune from there.
Wire Selection for FCAW
Choosing the right wire for your job requires understanding the AWS classification code printed on the spool. The code tells you what the wire is designed for.
AWS Classification Code Explained
The AWS classification for FCAW wires follows a standard format. Using E71T-1 as an example:
- E = Electrode (consumable)
- 7 = Minimum tensile strength in 10,000 psi increments (70,000 psi for T-7X; T-6X indicates 60,000 psi)
- 1 = Position capability (1 = all positions; 0 = flat and horizontal only; 2 = flat, horizontal, and vertical down; 3 = flat only; 5 = all positions with qualification)
- T = Tubular (flux-cored construction)
- Suffix tells you the shielding type, usability, and application:
- 1 = Gas-shielded, all position, multi-pass
- 8 = Self-shielded, all position, low-hydrogen, multi-pass (requires specific technique)
- 11 = Self-shielded, all position, general purpose, multi-pass
- GS = Self-shielded, all position, single-pass only
- 9 = Gas-shielded, all position, multi-pass, improved impact properties
- 12 = Gas-shielded, all position, multi-pass, low-hydrogen
- 14 = Self-shielded, all position, sheet metal and limited multi-pass
Common FCAW Wire Classes Reference Table
| AWS Class | Type | Positions | Polarity | Shielding Gas | Key Characteristics | Typical Uses |
|---|---|---|---|---|---|---|
| E71T-1 | Gas-shielded | All (1) | DCEP | CO2 or Ar/CO2 | General purpose, good appearance, multi-pass | Fabrication, structural, shipbuilding |
| E71T-8 | Self-shielded | All (1) | DCEN | None | Low-hydrogen, high impact, heavy slag | Field structural, bridge, heavy plate |
| E71T-9 | Gas-shielded | All (1) | DCEP | CO2 or Ar/CO2 | Higher impact properties, low-temp service | Pressure vessel, critical structural |
| E71T-11 | Self-shielded | All (1) | DCEN | None | General purpose, forgiving, moderate slag | Light fabrication, general repair |
| E71T-12 | Gas-shielded | All (1) | DCEP | CO2 or Ar/CO2 | Low-hydrogen, high impact, code work | Structural per D1.1, critical joints |
| E71T-GS | Self-shielded | All (1) | DCEN | None | Single-pass only, beginner-friendly, thin metal | Sheet metal, light repair, hobbyist |
| E71T-14 | Self-shielded | All (1) | DCEN | None | Sheet metal, limited multi-pass | Thin gauge, automotive repair |
Choosing Between Self-Shielded and Gas-Shielded Wire
The decision between FCAW-S and FCAW-G depends on your work environment, material, and quality requirements.
Choose self-shielded (FCAW-S) for:
- Outdoor and field work where wind makes gas shielding impractical
- Portable setups where carrying gas cylinders is a burden
- Repair and maintenance on dirty or rusty base metal (some wire classes have higher tolerance for surface contamination)
- Applications where gas logistics are a constraint
Choose gas-shielded (FCAW-G) for:
- Indoor shop work where wind is not a concern
- Production welding where bead appearance matters
- Applications requiring Charpy V-notch impact properties for low-temperature service
- Situations where lower fume generation is preferred
A note on E71T-GS: Per AWS A5.20, E71T-GS is classified for single-pass welds only. It is not designed for multi-pass applications. This wire is widely available and beginner-friendly, but the single-pass limitation is frequently overlooked. Do not use E71T-GS for multi-pass welds unless the specific manufacturer’s product data and a qualified WPS allow otherwise.
Wire diameter selection follows material thickness. Typical ranges: 0.030 inch for thin metal and light fabrication (FCAW-G), 0.035 inch for general purpose, 0.045 inch for moderate thickness, and 1/16 inch and larger for heavy fabrication and structural work.
Wire from different manufacturers with the same AWS classification is not identical. Formulations differ. Settings, slag characteristics, and spatter levels vary. Always start with the manufacturer’s recommended parameters for the specific spool you are using.
Technique Differences from MIG
If you have MIG experience, the technique adjustments for FCAW will feel deliberate at first. They become natural with practice.
Travel Direction: Drag Instead of Push
Most MIG welding uses a push technique, with the gun angled forward in the direction of travel. FCAW uses a drag (pull) technique, with the gun angled back toward the completed weld, typically 5 to 15 degrees from perpendicular.
The reason is slag management. FCAW generates slag that floats to the surface of the weld pool. Dragging the gun allows the slag to form behind the advancing arc. Pushing with FCAW can cause the slag to run ahead of the weld pool, leading to slag inclusions in the finished weld.
Some gas-shielded FCAW-G wires (especially certain T-1 products) can be run with a slight push or neutral gun angle in flat position. But drag is the standard teaching point for FCAW, and it is the safest starting point.
Stickout: Longer Than MIG
FCAW requires a longer electrode stickout (the distance the wire extends past the contact tip) than MIG. Typical ranges:
- Self-shielded FCAW-S: 3/4 inch to 1-1/4 inches
- Gas-shielded FCAW-G: 1/2 inch to 3/4 inch
- MIG comparison: Typical MIG stickout is 3/8 to 1/2 inch
The longer stickout preheats the wire before it enters the arc, improving deposition efficiency and stabilizing the arc. Self-shielded FCAW-S specifically depends on this extended stickout to allow the flux to fully react and generate adequate shielding gas. If your stickout is too short, you may get insufficient flux heating, inadequate shielding, and excessive spatter. If it is too long, the arc becomes unstable and penetration drops.
Travel Speed and Gun Angle
FCAW generally runs at moderate travel speeds, slower than MIG short-circuit transfer and comparable to MIG spray transfer. Travel speed affects slag coverage: too fast produces stringy slag that is hard to remove, while too slow creates excessive slag buildup.
Gun angle for FCAW is typically 5 to 15 degrees drag from perpendicular. For vertical-up welding, angle slightly upward. For vertical down (when appropriate for the wire class), angle downward. Not all wire classes perform equally in all positions. Check the position rating on the spool.
Arc Sound and Metal Transfer
FCAW has a distinctive arc sound. Self-shielded FCAW-S produces a frying, ripping sound. Gas-shielded FCAW-G produces a steady crackling sound more like MIG but with a different character. The arc is generally more active than MIG spray transfer. Metal transfer in FCAW is typically globular-to-spray, and self-shielded wire produces a unique transfer characterized by small droplets propelled axially. You learn to tune your settings by ear once you are familiar with the sound of a stable FCAW arc.
Slag Removal
FCAW produces slag that covers and protects the solidifying weld bead. This is different from MIG, which produces no slag. Slag characteristics vary significantly by wire class.
Self-shielded FCAW-S: Slag tends to be heavier and can be more tenacious. E71T-8 produces a distinctive heavy slag that fully encases the bead and may require chipping. E71T-11 and E71T-GS produce moderate slag that often self-peels or chips easily.
Gas-shielded FCAW-G: Slag is typically lighter. Many T-1 wires produce self-peeling or easily chipped slag. T-5 wires produce a heavier slag that is more difficult to remove.
Important: FCAW slag is not the same as stick welding slag. The slag systems are formulated specifically for the continuous-feed process and have different removal characteristics. Do not assume techniques from SMAW apply directly.
Slag removal is done with a chipping hammer after the weld has cooled, followed by a wire brush for light residues. Grinding may be necessary when heavy slag remains or when weld appearance demands it. Slag must be removed before multi-pass welding; embedded slag in a joint causes inclusions and lack of fusion in subsequent passes.
When to Choose FCAW
FCAW has specific strengths that make it the right choice for certain jobs. It is not universally better than MIG. It is different, with its own appropriate applications.
Outdoor and Field Welding
Self-shielded FCAW-S is the go-to process for outdoor structural welding, field repair, pipe welding, and construction. It does not require external shielding gas and tolerates wind better than any gas-shielded process. Lincoln Innershield wires (E71T-8, E71T-11) are widely used in structural steel erection and field welding for this reason.
Thick Material and Heavy Fabrication
Gas-shielded FCAW-G offers high deposition rates on heavy plate, often exceeding GMAW spray transfer rates in certain positions. Common applications include shipbuilding, heavy equipment manufacturing, and production fabrication where deposition speed matters.
Dirty or Rusty Base Metal
Self-shielded FCAW-S wires, especially T-8 and T-11 classifications, have higher tolerance for surface contamination than GMAW or FCAW-G wires. The flux provides deoxidizing and scavenging action that handles moderate contamination better than solid-wire processes. Surface preparation is still recommended and will produce better results, but FCAW-S is more forgiving when prep is limited.
Portability and Simplicity
Self-shielded FCAW-S with a small 120-volt MIG machine and E71T-GS wire allows welding without a gas cylinder, regulator, or hose. This is a common entry point for hobbyists and mobile repair work where gas logistics are impractical.
When MIG Is the Better Choice
MIG remains the better choice for thin sheet metal (under 18 gauge), aluminum and other non-ferrous metals (which require solid wire), indoor production of thin materials where short-circuit MIG excels, applications requiring minimal post-weld cleanup, and situations where bead appearance without slag removal is the priority. For thin-gauge work, MIG short-circuit transfer generally produces better results than FCAW.
Common Mistakes in FCAW
The most frequent mistakes beginners make with FCAW, especially those coming from MIG, fall into a few categories.
Wrong polarity. This is the number one mistake. Using DCEP (MIG polarity) with self-shielded FCAW-S wire, or DCEN with gas-shielded FCAW-G wire. Results include porosity, spatter, and poor fusion. Always check the wire manufacturer’s polarity recommendation before welding.
Incorrect stickout. Using MIG stickout (short) with self-shielded FCAW-S causes inadequate flux heating and poor shielding gas generation. With FCAW-G, incorrect stickout affects gas coverage and arc stability.
Pushing instead of dragging. MIG-trained welders tend to push the gun. With FCAW, pushing can cause slag inclusions and poor bead shape. Consciously adopt the drag technique.
Wrong drive roll setup. Using smooth V-groove rolls designed for solid wire can crush tubular flux-cored wire. Overtightening the feed head pressure deforms the wire. Using the wrong contact tip size causes burnback or erratic feed.
Ignoring the E71T-GS single-pass limitation. Running multi-pass welds with E71T-GS violates the AWS classification and risks weld metal brittleness. This is a common beginner trap.
Assuming all self-shielded wire runs the same. E71T-GS, E71T-11, and E71T-8 have different optimum settings, slag systems, and technique requirements. Read the spool and the data sheet.
Skimping on ventilation. FCAW-S produces significant fume. Adequate ventilation or fume extraction is required per OSHA standards.
Excessive wire feed speed. FCAW wire has different feed rate characteristics than MIG. Starting too high causes burnback or an unstable arc.
Safety Notes
FCAW has specific safety considerations beyond general welding safety. These are driven primarily by fume generation, spatter behavior, and polarity requirements.
Fume exposure. FCAW generally produces more fume than GMAW on equivalent base metal, with self-shielded FCAW-S producing the highest levels. The flux compounds in FCAW wire generate additional fume components compared to solid wire. Adequate ventilation or local exhaust ventilation (LEV) is required per OSHA 29 CFR 1910.252(c). If ventilation is insufficient, respiratory protection may be needed based on exposure assessment.
Spatter and slag hazard. FCAW-S produces significant spatter, generally more than MIG. Hot slag from FCAW can travel farther than MIG spatter and is a fire hazard. Proper PPE (leather gloves, flame-resistant clothing) and fire prevention measures (35-foot clearance from combustibles per OSHA 1910.252(a)) are essential. FCAW generates a large, fluid weld pool. Burns from slag drips, spatter, and contact with the workpiece are real risks.
Polarity switching hazard. Incorrect polarity can damage equipment and produce hazardous weld conditions. Always verify polarity per the wire manufacturer’s specification before welding. If your machine requires internal rewiring for polarity change, follow the manufacturer’s instructions precisely.
Electrode handling and storage. Flux-cored wire is moisture sensitive. Store in a clean, dry area. Low-hydrogen classifications (E71T-8, E71T-12) require storage in hermetically sealed containers or a ventilated holding oven at manufacturer-recommended conditions per AWS D1.1. Wires with damaged flux, visible rust, or suspected moisture contamination must be discarded.
Standard welding PPE applies. Welding helmet with proper filter shade per ANSI Z87.1, no exposed skin, welding gloves, flame-resistant clothing, and leather boots.
Understanding FCAW as its own process, respecting the self-shielded versus gas-shielded distinction, and following manufacturer guidance for your specific wire will get you to good results faster than trial and error. The process has been doing heavy industrial work for over seventy years. It works well when you work with it on its own terms.
