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What MIG Burnback Does

Burnback is the short period during which the welder keeps power on after you release the trigger. It melts the wire back slightly so the wire does not freeze into the weld puddle or stick to the contact tip. The setting is usually measured in seconds, although some machines show a numbered dial instead of an actual time.

A correct setting leaves a short, clean wire stub at the end of the weld. A setting that is too low leaves the wire fused to the workpiece or contact tip. A setting that is too high burns the wire back into the contact tip, creates a large ball on the wire end, or causes an inconsistent arc the next time you pull the trigger.

Burnback is not the same as post-flow. Post-flow keeps shielding gas over the weld after the arc stops. It also is not the same as crater fill, which controls the final portion of the weld before shutdown.

Starting Settings by Wire Feed Speed

Wire feed speed is a useful starting point because faster wire requires more burnback time to stop cleanly. These figures assume a conventional short-circuit MIG setup with solid steel wire, a clean contact tip, and a stickout of roughly 3/8 inch. They are starting ranges, not universal specifications.

Some welders use a scale from 0 to 10 rather than seconds. Do not assume “5” means 0.05 seconds. On one machine it may represent a short pulse, while on another it may be a much longer timed delay. If the manual lists a conversion, use it. Otherwise, make small adjustments and judge the wire end after several starts and stops.

How to Set Burnback Correctly

First, set the wire feed speed and voltage for the material and wire diameter. Burnback should be adjusted after the arc is otherwise stable. A poor ground, dirty steel, worn liner, wrong polarity, or incorrect voltage can look like a burnback problem.

Make a series of short welds on scrap of the same thickness. Keep the gun angle, stickout, and travel speed consistent. Release the trigger normally, then inspect the wire end and contact tip.

• If the wire is welded to the puddle or contact tip, increase burnback slightly.
• If the wire burns back into the contact tip, decrease burnback.
• If a large ball forms on the wire, reduce burnback or check that voltage is not too low.
• If the next start is harsh or the wire protrudes an unusually long distance, reduce the setting and inspect the liner.

Adjust in small steps—about 0.01 to 0.02 seconds where the machine allows it. A useful target is a clean wire stub about 1/8 to 1/4 inch long. Exact stub length varies with wire size, transfer type, and the welder’s circuit design, so arc behavior matters more than a specific measurement.

Why Wire Feed Speed Changes the Setting

At higher wire feed speeds, more wire enters the arc during the same fraction of a second. The welder therefore needs more shutdown time to melt the wire back to the desired length. At low speeds, the same burnback time can remove too much wire and leave the end fused inside the contact tip.

Wire diameter also matters. A 0.035-inch wire carries more metal than a 0.023-inch wire, so it may need a different setting even at the same feed speed. Solid wire with a gas shield, flux-core wire, short-circuit transfer, and spray transfer do not necessarily stop in the same way. Begin with the manufacturer’s recommended range when available.

Long gun leads and worn liners can add feeding resistance. They may cause an apparent burnback fault because the wire hesitates before shutdown or does not restart smoothly. Before adding a lot of burnback, replace a badly worn contact tip, clean or replace the liner, and verify that the drive rolls match the wire.

Consumables and Equipment That Affect Results

A good contact tip should match the wire diameter and hold the wire without excessive looseness. A tip that is worn oversized can produce wandering, unstable starts that no burnback setting will fully correct. If you regularly change wire sizes, keep spare tips in the correct sizes rather than trying to compensate with machine settings.

For occasional garage work, standard copper contact tips and a properly adjusted drive system are usually enough. Spending more on premium consumables makes more sense for long production runs, abrasive flux-core wire, or work where repeatable starts matter. You can compare MIG contact tips by size and thread before buying.

A machine with adjustable burnback is useful when you switch between thin sheet and heavy fabrication. If a welder has only a fixed setting, you can often work around it by keeping stickout consistent and using the recommended wire diameter. Do not buy a more expensive welder solely for burnback adjustment unless your current machine regularly sticks wire or produces poor starts.

Related Settings and Safe Testing

Burnback cannot correct excessive stickout. Keep contact-tip-to-work distance near the range recommended for the wire and transfer mode, commonly around 3/8 inch for short-circuit solid wire. Excessive stickout cools the wire and changes arc length; very short stickout increases spatter and can overheat the tip.

Use the correct shielding gas flow, protect the work from drafts, and remove paint, rust, oil, and galvanizing where appropriate. Wear a properly shaded auto-darkening welding helmet, welding gloves, flame-resistant clothing, and adequate ventilation. Test burnback on scrap, not on a finished part.

If the wire still sticks after reasonable adjustments, stop and check polarity, grounding, liner condition, drive-roll tension, contact-tip size, and the welder’s manual. The best setting is the lowest burnback time that consistently leaves a clean stub and gives a smooth restart.