7018 rod storage: drying, rod ovens and exposure limits
The 7018 has a reputation as a difficult rod, but a good part of that reputation comes from rods stored the wrong way. An open box in the corner of the shop, soaking up humidity from the air, is enough to make the arc unstable, fill the weld with pores and, in the worst case, crack the joint hours later. The rule is simple: low-hydrogen rods live in the oven.
Once the sealed container is open, keep 7018 (and other low-hydrogen rods) in a rod oven at about 250–300 °F (120–150 °C) and carry the day's rods in a portable rod oven. How long they may sit outside depends on the rod maker and the code (AWS D1.1); after that they go back to the oven or get reconditioned. Exact times and temperatures: follow the package and the WPS.
Why moisture ruins 7018
The coating on a rod is the “shielding gas” of stick welding. On the 7018 that coating is low-hydrogen, and it absorbs moisture from the air. In the arc, the water breaks down and releases hydrogen, which enters the molten metal.
The result shows up in two ways. The most visible is porosity: even pinholes along the bead. The most dangerous is cold cracking (hydrogen cracking), which can appear hours or even days after welding and is sometimes invisible to the eye. It is the reason 7018 is used on critical structures only when it is properly dry.
Rutile, cellulosic and low-hydrogen: who needs an oven
| Rod | Coating | Moisture sensitivity | How to store |
|---|---|---|---|
| E7018 | Low-hydrogen | Very high | Rod oven after opening; portable oven on the job |
| E6013 | Rutile | Lower, more forgiving | Closed package, in a dry place |
| E6010 / E6011 | Cellulosic | — | Follow the package: do not treat it like low-hydrogen |
Table 3.1 and the low-hydrogen rule (Section 3.2) of the e-book The Welder's Forge.
Cellulosic rods work differently, and drying them hot can damage the coating, so the hot-oven rule is for low-hydrogen rods. When in doubt, the maker's package rules.
The oven routine, in practice
- New package opened: the rods go straight into the oven, not onto the bench.
- On the job: take only what you will use in a portable oven that is switched on, not in a pocket or an open box.
- Track the time outside: past the limit (often a few hours, with 4 hours a common limit for 7018, but it depends on the code, the rod type and the maker)? Back to the oven, or reconditioned per the maker's instructions, before you use them.
- Truly wet rods, with a swollen, cracked or flaking coating: throw them out. Redrying does not repair a damaged coating.
The complete e-book
Reference tables, stick, MIG/MAG and TIG technique and safety in one PDF, written in plain American English.
Holding temperature and reconditioning temperature are not the same thing. Holding keeps dry rods dry. Reconditioning is a separate, much hotter bake, in the range of 500–800 °F (260–425 °C) for many low-hydrogen rods, with a time and temperature that differ by maker. Never guess it: use the numbers on the package.
For gates, railings and home repairs, 6013 does the job and is much more forgiving: keep the package closed in a dry place, off the floor and away from damp walls. Save the 7018 for when the job calls for it and you have a way to keep it dry. Which one to choose in each case is in 6013 vs 7018.
Signs of damp rods at the bench
| What you see | Likely cause | First fix |
|---|---|---|
| Even pores in the bead | Moisture in the rod | Dry the consumables; preheat when indicated |
| Droplets stuck around the bead | Spatter | Shorten the arc; dry the rod; check the polarity |
| Arc that strikes poorly and wanders | Damp rod or chipped coating | Change the rod; recondition the lot |
Tables 12.1 and 12.2 of the e-book The Welder's Forge.
Pores also come from dirt, a long arc and low current; the full diagnosis is in weld porosity. And if a damp rod is sticking when you strike, see welding rod sticking to the metal.
Match the oven to the right supply (120 V or 240 V, read the nameplate), keep it away from flammables and on a proper outlet, with no improvised extension cord. Open it and handle rods with gloves: they come out at well over 250 °F (120 °C).
Frequently asked questions
What temperature should a 7018 rod oven be?
How long can 7018 stay out of the oven?
What is a portable rod oven?
Does 6013 need an oven?
Want all of this in one PDF?
The e-book The Welder's Forge covers stick, MIG/MAG and TIG from the first arc to the shop floor, with reference tables and technical figures, in plain American English.
PDF for phone, tablet or computer · instant access · 14-day guarantee