Stick Welding Pipe Root Passes: E6010 Then E7018
Ask an experienced pipe welder how to build a stick weld on a joint and you will often hear the same answer: E6010 for the root, E7018 for everything after. The pairing is a classic because each rod does the job the other one cannot. This guide explains why, where each electrode fits, and what to keep in mind when you stock both.
Why two different electrodes?
A root pass has to fuse the two pipe ends, penetrate the joint, and freeze fast enough to hold its shape across the gap. Fill and cap passes have a different job: stack clean, strong weld metal on top. No single stick electrode is the best at both, so pipe welders switch rods.
HYW E6010 is a high-cellulose sodium electrode that runs on DC+ (reverse polarity). Its tight, forceful, fast-freezing arc digs into the joint and works well on rust, scale and imperfect fit-up. E7018 is a low-hydrogen, iron-powder electrode with a smoother arc and a 70,000 psi minimum tensile strength, which makes it the usual choice for fill and cap passes.
E6010 vs E7018 at a glance
| Feature | E6010 | E7018 |
|---|---|---|
| Typical role on pipe | Root pass | Fill and cap |
| Coating | High cellulose sodium | Low hydrogen, iron powder |
| Arc character | Deep, digging, fast-freezing | Smooth, soft, stable |
| Min. tensile strength | 60,000 psi | 70,000 psi |
| Current | DC+ (DCEP) | DC+ or AC, per the product data sheet |
| Handling | Keep dry; do not oven-bake | Keep dry; rod oven after opening a can |
How the sequence works
- Root pass (E6010): open the joint and fuse both pipe ends. The fast-freezing puddle helps you control the keyhole and the root bead.
- Hot pass: many shops follow with E6010 again to clean up and burn out slag traps in the root before it cools. Follow your welding procedure specification (WPS) for the exact sequence.
- Fill and cap (E7018): switch to the low-hydrogen rod to stack smooth, strong layers and finish with a neat cap.
Rod sizes, amperage and direction of travel depend on pipe wall thickness, position and the governing code, so always work to your qualified WPS rather than a rule of thumb. For reference, the HYW E6010 product page lists 3/32 in at 40 to 80 A, 1/8 in at 75 to 130 A, and 5/32 in at 110 to 165 A as general guidelines.
Where this pairing is used
- Pipe and pipeline joints
- Storage tanks and pressure piping
- Structural steel and field construction
- Repair and maintenance on unprepared steel
Storage matters for both rods
The two electrodes want opposite treatment. E7018 is low hydrogen, so moisture pickup is a real concern, and opened cans should go into a rod oven. E6010 relies on a controlled level of coating moisture for its arc, so avoid high-temperature oven baking. Hermetically sealed 50 lb cans keep both rods dry until you open them. For more on this, see our guide on which stick rods need a rod oven.
Buying and bulk
Pipe crews burn through root rod quickly, and running out mid-joint is expensive. Both rods are available in 50 lb hermetically sealed cans, with 10 lb boxes for smaller jobs. If you run a shop or a crew, contact us about bulk and pallet pricing.
Stock the full root-to-cap set
Shop E6010 50 lb sealed can and E7018 50 lb sealed can, or browse the full E6010 collection and E7018 collection.
FAQ
Why not run E7018 for the root pass?
Some procedures do call for it, but E6010 is favored on open roots because its forceful, fast-freezing arc gives deep penetration and good control of the root bead.
Can I use the same machine for both rods?
Yes, a DC stick machine will run both. E6010 needs DC+, so check your machine's polarity before you start.
Do I need to dry E6010 in a rod oven?
No. As a cellulosic rod it depends on some coating moisture, so avoid high-temperature baking. Store it dry and reseal the can between uses.
Which diameter should I use for the root?
It depends on wall thickness, joint gap and your WPS. Smaller diameters such as 3/32 in and 1/8 in are common for root passes, but follow your procedure.
Safety: Welding fumes, arc rays and hot metal are hazardous. Use proper ventilation, eye and skin protection, and follow the manufacturer's instructions and applicable codes. Always weld to a qualified procedure for code work.