What's inside
As an Amazon Associate I earn from qualifying purchases. This post may contain affiliate links at no extra cost to you.
Hot start is the brief increase in welding current at the moment an inverter stick welder detects that you are striking an arc. It helps the electrode start without sticking, especially with difficult-to-start rods such as 6010 and 6011. It can also reduce the small cold section at the beginning of a weld.
On most machines, hot start is adjusted with a percentage, an amperage boost, or a simple low-to-high control. The setting is usually separate from the main welding-current knob. It only works during arc initiation, typically for a fraction of a second, so it is not a substitute for setting the correct welding amperage.
What Hot Start Does
When a stick electrode touches cold metal, the arc may be difficult to establish. The rod can freeze to the work before the arc becomes stable. Hot start briefly raises the output current—often by roughly 20 to 100 percent above the selected welding current—then returns to the normal setting.
For example, if the welder is set to 90 amps and hot start adds 40 percent, the machine may briefly deliver about 126 amps. The exact output and timing depend on the welder. Many compact inverters do not provide precise control, so the numbers on the dial should be treated as a starting point rather than laboratory measurements.
A useful hot-start setting should make the arc start cleanly without producing a large flash, excessive spatter, or a crater at the beginning of the bead.
How to Set Hot Start
First, set the main amperage for the electrode and material. For a general starting point, a 1/8-inch 6013 rod often runs around 90 to 125 amps, while a 1/8-inch 6011 commonly works around 75 to 120 amps. Follow the electrode manufacturer’s range when available. Rod type, joint position, steel thickness, and polarity all affect the correct setting.
Set hot start near the middle of its available range. Strike an arc on scrap steel of the same approximate thickness, using the same electrode and polarity as the real weld. Watch the first 1/4 to 1/2 inch of the bead, not just whether the rod starts.
- If the rod sticks repeatedly, increase hot start slightly.
- If the arc starts with a violent pop and throws metal, reduce it.
- If the bead begins with a wide, deep gouge, reduce the setting or shorten the hot-start duration.
- If the start is dull and the electrode drags before stabilizing, add a small amount.
Make adjustments in small steps. On a percentage-controlled machine, change by about 5 to 10 percentage points at a time. On a low-to-high knob, move only one or two marks. Always retest after changing the main amperage, because a hot-start setting that works at 80 amps may be excessive at 140 amps.
Hot Start Settings by Electrode
| Electrode | Typical starting approach | Hot-start requirement | Common problem when too high |
|---|---|---|---|
| 6010 or 6011 | Use the rod maker’s range; often a firm, fast arc | Medium to high | Violent ignition, excessive spatter, undercut |
| 6013 | Moderate current with a smoother arc | Low to medium | Large start crater or a blown-through edge |
| 7018 | Use correct storage and the recommended current | Low to medium | Porosity, spatter, or a rough first inch |
| Stainless or hardfacing rods | Follow the specific rod instructions | Usually low to medium | Overheating, cracking, or excessive dilution |
6010 and 6011 rods often benefit most because their arc can be harder to establish on rusty or contaminated steel. 7018 rods can also stick if the arc length is wrong, but turning hot start to maximum is not the cure. Correct amperage, dry electrodes, clean contact surfaces, and a quick scratch or tap start matter more.
Hot Start Versus Arc Force
Hot start acts at ignition. Arc force, sometimes called dig, acts while you are welding and the arc length becomes short. Arc force increases current momentarily to help prevent the electrode from sticking during tight arc conditions.
| Control | When it works | What it changes |
|---|---|---|
| Hot start | At arc initiation | Makes the rod easier to light and can improve the first part of the bead |
| Arc force | During a short or unstable arc | Adds digging action and helps resist sticking |
| Main amperage | Throughout the weld | Sets the normal heat and penetration level |
If the rod starts easily but sticks whenever you shorten the arc, adjust arc force instead of hot start. Too much arc force can make a normally smooth 6013 electrode harsh and spattery.
Choosing a Welder With Hot Start
For occasional repairs, a low-cost inverter with automatic or fixed hot start is often adequate. You do not need a fully adjustable control to weld brackets, gates, farm equipment, or general mild-steel repairs. Look for a machine with a believable duty cycle, stable output at low amperage, and the correct input voltage for your shop.
If you use several rod types, weld thin material, or need repeatable starts, adjustable hot start is worth paying for. A machine with separate hot-start and arc-force controls gives you more control than one advertised only as having “anti-stick.” Anti-stick generally reduces current after the rod has already stuck; it does not replace a useful hot-start circuit.
When comparing machines, consider inverter stick welders with adjustable hot start if you regularly use 6010, 7018, or stainless electrodes. For basic repair work, a dual-voltage inverter stick welder can be a better upgrade than paying extra solely for more hot-start adjustment.
Safety and Troubleshooting
Hot start can produce a brighter initial arc and more spatter. Wear a properly rated welding helmet, gloves, nonflammable clothing, and leather footwear. Keep flammable materials away from the work area, and clamp the work lead to clean metal rather than painted or rusty surfaces. Use a quality auto-darkening welding helmet with a shade suitable for the welding current.
If the rod still sticks with high hot start, check the basics: verify electrode polarity, clean the work clamp connection, remove heavy scale, and confirm that the machine is not overheating or operating on an undersized extension cord. If the first inch is sound but the rest of the bead is poor, hot start is not the problem. Correct the main amperage, arc length, travel speed, or electrode angle instead.
For repeatable results, mark the settings that work on a scrap test: rod type, diameter, polarity, amperage, hot start, and arc force. That small record is more useful than leaving every control at maximum.