What's inside
As an Amazon Associate I earn from qualifying purchases. This post may contain affiliate links at no extra cost to you.
A stick arc restart is a small weld made under awkward conditions: the rod has to strike, establish a steady arc, and tie into the previous bead without leaving a crater, slag pocket, or cold lap. The fix is mostly preparation and a repeatable restart technique. If you keep welding over a rough stop, the defect can remain hidden until the joint is inspected or loaded.
Why restarts fail
When you stop welding, the puddle cools and contracts, often leaving a crater at the end of the bead. Slag can cover that crater. If you strike on top of the slag or start too far away from the bead, the new puddle may not fuse cleanly into the old one. Common results include a pinhole, trapped slag, a raised lump, or an unfused seam.
A restart can also fail because the rod sticks. This is more likely with a damp or contaminated workpiece, poor ground connection, low amperage, or an electrode that has picked up moisture. A sticking rod is not just an inconvenience: pulling it free can damage the coating, and forcing the next strike can leave an irregular bead.
Prepare the joint before striking
Chip away slag at the bead end and brush the area until you can see clean metal. Use a chipping hammer and a wire brush; don’t assume that a dark surface is clean just because it looks smooth. If the stop ended in a deep crater, grind it back to sound weld metal and feather the edge so the restart can blend in. Remove paint, rust, oil, and moisture from the surrounding base metal as well.
Check that the work clamp has a solid connection to clean metal. Make sure the electrode is dry and undamaged, and confirm that the polarity and current match the electrode maker’s guidance. A typical 1/8-inch E6013 or E7018 electrode often runs somewhere around 90–130 amps, but the right setting depends on the electrode, position, machine, and joint. Use the range printed on the electrode package as your starting point, then test on scrap of similar thickness.
A basic chipping hammer and wire brush are enough for routine cleanup. A small grinder is useful when a crater is too deep or the bead is irregular, but it removes more metal and can thin a small workpiece if you lean on it.
Strike and restart in a controlled way
With your helmet down and a steady hand position, strike the rod on clean metal just ahead of the previous bead, then move it back toward the bead end as the arc establishes. Keep the rod angle and arc length consistent. A drag or scratch start can work; use the method you can control without gouging the plate or scattering the arc across the joint.
As the puddle forms at the old bead, pause briefly to let it wash into the bead end. Then continue along the joint at your normal travel speed. Don’t hold the arc in place for a long time: excessive dwell can make a bulky spot, burn through thin material, or overheat the electrode. The aim is a smooth overlap, not a separate blob sitting on top of the old weld.
For a short restart, overlap the earlier bead by roughly 1/4 to 1/2 inch where the joint and weld size allow. That gives the new puddle time to fuse into sound metal. On thin stock, use a shorter overlap and watch for burn-through. On a thick or highly restrained joint, follow the applicable welding procedure rather than treating that distance as a universal rule.
Which restart method fits the job?
| Method | Best use | Trade-off |
|---|---|---|
| Strike ahead, then move back | General repairs and short beads | Simple to control, but needs a clean patch of metal for the strike |
| Strike on the bead and move forward | When there is no room ahead of the weld | Can leave a high spot if you don’t blend the puddle into the old bead |
| Grind the stop and restart on a feathered edge | Critical welds, deep craters, or slag-trapping risk | More preparation; grinding can remove too much material |
Whichever method you use, avoid restarting directly on loose slag. If you have to strike near the bead, first expose clean metal and aim to melt into the old weld rather than simply laying new metal over it.
Recognize and correct common problems
The rod sticks on contact: Check the ground, clean the strike area, and increase amperage slightly if you are below the electrode’s recommended range. Don’t compensate by holding the rod hard against the plate. For practice, a mild-steel practice coupon lets you test settings without risking the actual workpiece.
The restart leaves a crater or pinhole: The arc may have stopped too abruptly, or the puddle may not have filled the end. At the next stop, slow down slightly and shorten the arc as you finish, adding enough metal to fill the crater. At a restart, clean out any crater that remains before welding over it.
Slag is trapped at the join: Stop and clean more thoroughly. If the seam still looks suspect, grind out the restart to clean, sound metal and weld it again. A fresh bead over an unremoved slag inclusion does not fix the defect.
The join is a raised lump: The restart may have overlapped too far, moved too slowly, or used excessive current. Grind the high spot only as needed to restore the bead profile, and check that you have not ground below the surrounding weld. Thin sheet is especially easy to damage this way.
Inspect before calling it done
After the weld cools enough to handle safely, chip and brush the slag. Look for a continuous bead with no visible cracks, pinholes, undercut, or sharp notch at the restart. A restart that looks smooth is not automatically sound, particularly on a structural or safety-critical joint. Follow the required inspection method and welding procedure for that work; visual checks alone cannot find every internal defect.
For ordinary practice or noncritical repairs, clean metal, a correctly set machine, and a deliberate overlap are usually enough. If you repeatedly get sticking, porosity, or visible cracks despite good preparation, stop and troubleshoot the electrode storage, polarity, machine output, and joint fit-up before making more passes.