Your MIG wire is burning back and fusing to the contact tip, stopping your weld cold. This happens when the wire arcs at the tip instead of at the workpiece—a sign of poor contact, dirty metal, or feeding issues. Fix it in 10 minutes with the right diagnosis.
Key Takeaways
- Contact tip burnback stops the arc and wastes time; most fixes are free or under $30
- Root causes: dirty contact tip, poor base metal prep, wire feed tension, or loose electrical connections
- Quick fix: clean the tip, prep your metal, check wire tension, and verify electrical connections
- Prevent burnback: replace tips every 50–100 hours of welding, use fresh wire, and keep the gun cable straight
Quick Diagnosis
What You’ll See:
- Wire sticks to the contact tip instead of feeding smoothly
- Arc won’t start or cuts out mid-weld
- Tip glows red or shows visible discoloration
- Wire may be bent or balled up inside the tip
Most Likely Causes (Ranked by Frequency):
- Dirty or worn contact tip (most common)
- Rusty or mill-scale base metal (prevents good arc start)
- Wire feed tension too tight or too loose
- Loose electrical connections (gun, ground clamp, or machine)
- Bent gun cable or kinked liner (restricts wire flow)
Safety Notes
- PPE: Wear ANSI Z87.1-rated helmet (down), welding gloves, and long sleeves. Contact tip burnback can cause sudden arc flare.
- Ventilation: MIG welding produces fume; ensure adequate shop ventilation or use a fume extractor per ANSI Z49.1.
- Electrical: Disconnect the machine or switch to standby before removing the tip or inspecting the gun.
- Hot Tip: Contact tips retain heat; let cool for 30 seconds before touching.
Step-by-Step Troubleshooting
Step 1: Inspect the Contact Tip (Free)
- Remove the nozzle and diffuser from the gun.
- Look inside the tip opening. If you see spatter, discoloration, or a balled-up wire, the tip is dirty or worn.
- Why: Spatter buildup reduces contact between the wire and tip, causing arcing instead of feeding.
- Fix: Use a small wire brush or a contact tip cleaner to scrub the inside of the tip. If the opening is enlarged or pitted, replace the tip (see Step 5).
Step 2: Check Your Base Metal (Free)
- Inspect the area where you’re welding. Look for rust, mill scale (gray/black oxide), or paint.
- Why: Dirty metal prevents good electrical contact, forcing the wire to arc at the tip instead of the workpiece.
- Fix: Use a wire brush, flap disc, or grinder to clean the weld area to bare metal. Wipe away dust.
Step 3: Verify Wire Feed Tension (Free)
- Locate the wire drive roll tension knob on your machine (usually on the side of the feeder).
- Loosen it slightly, then tighten until you feel light resistance when pushing the wire by hand.
- Why: Too much tension deforms the wire and causes slipping; too little causes the wire to slip in the rolls, starving the arc.
- Fix: Adjust to a gentle grip—the wire should feed smoothly without binding.
Step 4: Check Electrical Connections (Free)
- Verify the ground clamp is clamped directly to clean, bare metal on the workpiece.
- Check that the gun cable is plugged firmly into the machine.
- Inspect the gun trigger connection for corrosion or looseness.
- Why: Loose connections increase resistance, weakening the arc and causing burnback.
- Fix: Clean corroded connections with a wire brush and re-tighten.
Step 5: Inspect the Gun Cable and Liner (Free to $30)
- Straighten the gun cable. If it’s kinked or coiled, it restricts wire flow.
- Look inside the cable for a white or clear plastic liner. If it’s cracked, burnt, or clogged, the wire binds.
- Why: A damaged liner creates friction, slowing the wire and causing it to arc at the tip.
- Fix: If the cable is kinked, straighten it. If the liner is damaged, replace the gun cable or just the liner (see Step 6).
Step 6: Replace the Contact Tip and Liner (if needed) ($20–$50)
- If the tip is pitted, enlarged, or won’t clean, replace it with a new one matching your wire size (0.035″, 0.8mm, etc.).
- If the liner is clogged or damaged, replace it too.
- Why: A worn tip has poor contact; a clogged liner starves the arc.
- Fix: Install new consumables and test.
Fix Options (Ranked)
- Adjustment (Free) — Clean the tip, prep the metal, adjust wire tension, and check electrical connections.
- Consumable Change (~$20–$50) — Replace the contact tip and/or liner if they’re worn or clogged.
- Gun Cable Replacement (~$50–$150) — If the cable is kinked or the liner is damaged beyond cleaning.
- Machine Check (~$100+) — If burnback persists after all above steps, the machine’s wire feeder or power supply may need service.
Recommended Fix: Contact Tip Replacement Kit
If you’ve cleaned the tip and it still won’t work, or if you’re welding regularly, a multi-pack of contact tips ensures you always have a fresh tip on hand. Worn tips are the #1 cause of burnback; replacing them every 50–100 hours of welding prevents the problem before it starts.
Why It Works:
- New copper tips have perfect contact geometry, ensuring smooth wire feed and strong arc start.
- High-quality copper resists spatter buildup and heat damage longer than worn tips.
- A 30-pack gives you backups, so you’re never stuck mid-job.
When to Use It:
- Your tip is pitted, enlarged, or won’t clean.
- You weld more than 10 hours per week.
- You want to prevent burnback before it happens.
When NOT to Use It:
- If the problem is dirty metal or loose electrical connections (fix those first).
- If the gun cable is kinked (straighten or replace the cable first).
What to Check Before Buying:
- Match the tip size to your wire (0.035″, 0.8mm, etc.).
- Confirm compatibility with your gun type (15AK, 24KD, MB15, etc.).
- Verify the tip is copper, not steel (copper conducts better).
- Check reviews for spatter resistance and durability.
No products found.
Comparable Options
If you prefer a smaller pack or different wire size:
- Lincoln Electric MIG Contact Tips (various sizes): https://www.amazon.com/s?k=lincoln+electric+mig+contact+tips&tag=weldsupport-20
- Tweco Contact Tips (OEM quality): https://www.amazon.com/s?k=tweco+contact+tips&tag=weldsupport-20
Common Mistakes
- Using a worn tip and hoping it works. A pitted tip won’t conduct current evenly; replace it.
- Not cleaning the base metal. Rust and mill scale block the arc; always prep the metal first.
- Over-tightening wire feed tension. This deforms soft wire (especially aluminum) and causes slipping.
- Ignoring a kinked gun cable. A bent cable restricts wire flow just as much as a clogged liner.
- Blaming the machine when the problem is the tip. 90% of burnback is a dirty or worn tip; check it first.
FAQ
Q: Can I clean a burnt contact tip and reuse it? A: Yes, if it’s just spatter. Use a contact tip cleaner or small wire brush. If the opening is enlarged or pitted, replace it—a worn tip won’t conduct properly.
Q: How often should I replace my contact tip? A: Every 50–100 hours of welding, or sooner if you see spatter buildup or burnback. Frequent welders replace tips monthly.
Q: Why does my wire burn back even after I cleaned the tip? A: Check your base metal (is it rusty?), wire feed tension (is it too tight?), and electrical connections (is the ground clamp clean?). Burnback is rarely just the tip.
Q: Can a kinked gun cable cause burnback? A: Yes. A bent cable restricts wire flow, starving the arc. Straighten the cable or replace it if it’s cracked.
Q: What’s the difference between burnback and wire sticking? A: Burnback is when the wire fuses to the tip (arc at the tip, not the workpiece). Wire sticking is when the wire jams in the tip but hasn’t melted. Both have similar causes: dirty tip, poor prep, or feeding issues.
Next Steps
- Clean your contact tip and base metal — most burnback stops here.
- Check wire feed tension and electrical connections — free fixes that work 80% of the time.
- Replace the tip if it’s pitted or worn — use the kit above for a reliable spare.
- Explore related guides:
- MIG Wire Selection Guide — ensure you’re using the right wire for your job
- Auto-Darkening Helmet Buying Guide — see the arc clearly and catch problems early
- Welding Ground Clamp Setup — proper grounding prevents arc issues
For more welding fixes and gear options, see our full resource page: https://blog.weldsupportparts.com/links/
