Burnback is when the MIG wire melts back and welds itself to the contact tip, stopping the feed and forcing you to cut wire and swap parts. The fast fix is usually a fresh tip + a quick wire-speed correction, not a full re-tune of your machine.
Where to Buy (Quick Fix Parts)
Most likely failed components for burnback (in order):
- Contact tip (worn/oversized, dirty, or wrong size for the wire)
- Nozzle/diffuser area (spatter buildup causing poor gas coverage and heat issues)
- Liner (drag causing wire to hesitate, then burn back)
Key Takeaways
- Burnback usually means the arc is melting wire faster than it’s feeding (wire speed too low, or feed is slipping).
- Replace the contact tip first if the problem isn’t fixed in 2–3 minutes.
- Don’t “chase it” by changing multiple settings at once—fix one variable at a time.
- If wire feed feels inconsistent, suspect liner drag or drive-roll tension before you keep turning voltage up/down.
Symptoms (Fast Diagnosis)
- Wire sticks in the tip right at arc start
- You hear the arc, but wire stops advancing
- Tip is hot and the wire is fused inside
- Excessive spatter buildup in the nozzle right before it happens
- Wire feed feels “surgy” or inconsistent even before the burnback
Root Causes (Mapped to Symptoms)
- Wire fuses to tip at arc start → wire speed too low, stickout too short, tip partially blocked, poor ground
- Burnback after a few seconds of welding → tip overheated/worn, wrong tip size, excessive spatter restricting gas, incorrect technique (too close)
- Wire feed surges then sticks → drive-roll tension wrong, liner drag, kinked gun lead, worn rollers
- Repeated burnback after tip changes → wrong polarity for wire type, incorrect process setup, or a deeper feed restriction upstream
Quick Fix (Do This First)
Do these in order. Stop as soon as the problem is gone.
- Replace the contact tip (correct size for your wire diameter).
- Clip wire clean and re-seat the tip tight (loose tips can arc internally).
- Increase wire speed slightly (small change first).
- Check stickout (don’t run extremely short stickout unless the procedure calls for it).
- Check drive-roll tension (enough to feed, not enough to crush/flatten wire).
Step-by-Step Fix
- Confirm wire diameter matches the tip and drive rolls
- Wrong tip size = poor electrical contact or overheating.
- Wrong drive roll groove = slipping or deforming wire.
- Inspect the contact tip (replace if any doubt)
Replace if you see: ovaled bore, heavy spatter inside, discoloration/overheating, or inconsistent feed through the tip. - Set wire speed before you touch voltage
- If the wire keeps burning back: wire speed is typically too low or feed is slipping.
- Increase wire speed in small steps until the arc stabilizes.
- Check stickout and gun angle
- Too short stickout increases heat at the tip fast.
- Keep a consistent stickout and avoid “stuffing” the puddle.
- Check drive-roll tension and spool brake
- Too loose: slipping → wire pauses → burnback.
- Too tight: deforms wire → liner drag → inconsistent feed.
Set tension so it feeds reliably without crushing the wire (verify by observing consistent feed at the gun).
- Rule out liner drag
- Straighten the gun lead.
- If feed improves when straight, your liner is likely dirty/worn or the lead routing is the issue.
- Confirm basics that cause repeat burnback
- Ground clamp on clean metal (paint/rust causes instability).
- Correct polarity for the wire type (verify with your wire manufacturer).
Parts That Actually Fix This
- Contact tips
Replace when: burnback repeats, bore is worn, wire feels tight through the tip, or you see internal spatter.
Adjust when: tip is new/clean and the issue is clearly settings-related. - Liner
Replace when: feed improves only when the lead is straight, wire feels “draggy,” or you’ve had repeated feed issues.
Adjust when: the lead routing is kinked or you’re running an unnecessarily tight bend radius. - Drive rolls
Replace when: grooves are worn smooth, wire slips at normal tension, or wire is being crushed/flattened.
Adjust when: tension is clearly too high/low or the wrong groove is being used. - Diffuser / nozzle (if spatter is severe)
Replace when: threads are damaged, gas flow is disrupted, or spatter buildup is constant and unmanageable.
Adjust when: it just needs cleaning and the gas setup is correct.
Replace vs Adjust (Fast Decision Table)
| Problem | Adjust First | Replace |
|---|---|---|
| Wire fuses to tip on arc start | Increase wire speed slightly; confirm stickout | Contact tip (first), then check liner if feed is inconsistent |
| Burnback repeats after small wire-speed increase | Check drive-roll tension; straighten gun lead | Contact tip + inspect diffuser/nozzle; replace liner if drag persists |
| Feed surges then sticks | Drive-roll tension; spool brake; lead routing | Liner (common), drive rolls (if worn) |
Rule: If it’s not fixed in 2–3 minutes, replace the consumable (start with the contact tip).
Prevention Tips
- Keep consumables on a simple interval: tips/nozzles are wear items—replace before they cost you downtime.
- Avoid tight bends in the gun lead during welding (especially on small machines with softer wire).
- Keep wire clean and dry; dirty wire accelerates liner wear and tip fouling.
- Clean the nozzle/diffuser area routinely to prevent spatter restricting gas and overheating parts.
Safety note: Use an ANSI Z87.1-rated welding helmet and safety glasses, wear gloves, and ensure proper ventilation—burnback events often come with extra spatter and fume.
FAQ
How to fix MIG burnback fast?
Replace the contact tip first, clip wire clean, tighten the tip, then increase wire speed slightly. If feed still surges, inspect liner drag and drive-roll tension.
Why does my MIG wire stick to the tip when I start welding?
Most commonly: wire speed is too low, stickout is too short, the tip is worn/dirty, or the tip is loose and arcing internally.
Can a bad liner cause burnback?
Yes. If the liner drags, wire feed becomes inconsistent. The arc melts wire while the feed hesitates, which can fuse wire into the tip.
Should I change voltage to stop burnback?
Not first. Start with tip condition and wire feed consistency. Then fine-tune voltage only after feed is stable.
Internal Links (Related Guides)
- For the full diagnostic flow, see complete MIG wire feed troubleshooting: https://blog.weldsupportparts.com/
- If your issue flips between feed jams and tip fusion, read birdnesting causes and fixes: https://blog.weldsupportparts.com/tag/tension-adjustment/
- For wire selection variables that affect feed stability, see MIG wire selection guide: https://blog.weldsupportparts.com/2025/12/04/mig-welding-wire-selection-guide-2025-er70s-6-vs-er70s-3-specs/
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