How Should You Store 7018 Welding Rods Once the Can Is Open?

Two redry numbers circulate for 7018: 500 to 800 F and 650 to 750 F. Both come from Lincoln, and they are not in conflict. One is the generic range for the whole AWS A5.1 low-hydrogen class, the other is Lincoln's figure for its own E7018. The rest of this page assembles the holding, exposure and redry figures from two manufacturers side by side, settles which number to use, and then deals with the question most home shops are actually asking: what you can do without an oven, and where that stops being good enough.

Why opened 7018 needs special treatment

The "8" in E7018 is a low-hydrogen coating. It ships in hermetically sealed cans because the coating picks up water from the air, and moisture in the coating becomes hydrogen in the weld. Lincoln's storage document says the result can be hydrogen-induced cracking, "particularly in steels with a yield strength of 80,000 psi (550 MPa) and higher."

The part that matters for storage is how little warning you get. Lincoln describes three stages:

So "it runs fine" is not evidence that the rods are dry. A rod that misbehaves in the arc is already well past the point where the hidden damage starts. Storage is how you avoid having to guess.

The numbers, gathered from the data sheets

No single source carries all of these. Lincoln's current storage sheet (MC22-140, dated 12/22), an earlier Lincoln article reprinted by Rod Ovens, and two Hobart E7018 H4R data sheets each print part of the picture, and they disagree in ways that matter.

Read across the columns and three things are settled.

The holding temperature is not in dispute. Every source brackets 250 to 300 F. Set a holding oven there and you satisfy all four.

The exposure limit depends on the rod and on the code. Lincoln's "twice per shift" for standard rods works out, on an 8 hour shift, to the 4 hours its earlier text stated outright. Rods with an R suffix in the AWS classification are tested for moisture pickup after 9 hours of exposure, which is where the 9 hour figure comes from, and Lincoln's Excalibur 7018 MR brochure reports its moisture pickup after nine hours of exposure, charted at 80 F and 80 percent relative humidity. But Hobart's 718 sheet shows the same rod gets 9 hours under AWS D1.1 (structural steel) and only 4 under AWS D1.5 (bridges). The rod does not decide the limit on its own. The code does.

Redry temperature is where the confusion lives. That gets its own section.

500 to 800 F or 650 to 750 F: which one is right

The brief version: use the number printed for the brand in your hand. When that is Lincoln E7018, it is 650 to 750 F (340 to 400 C).

The 500 to 800 F range is real. Lincoln's earlier article gives it as the "typically" range for mild steel low-hydrogen electrodes under AWS A5.1, and immediately adds that "the manufacturer's recommendations should be followed." Hobart prints the same 500 to 800 F on its 718 data sheet. It is an envelope wide enough to cover every maker's product in the class.

Inside that envelope, each maker picks its own window. Lincoln's current table puts E7018 at 650 to 750 F. Hobart's 418, also an E7018 H4R, gets a single figure of 575 F. Those two do not overlap, and Lincoln is explicit that going hotter is not harmless: "DO NOT dry electrodes at higher temperatures."

Both figures keep circulating because the generic range is the one printed in general guidance, Lincoln's own earlier article and Hobart's 718 sheet included, while the narrow figures only appear on product-specific tables. The trap runs in both directions:

• Treating 500 F as good enough for Lincoln rods. It is inside the generic envelope but 150 F below Lincoln's floor. Lincoln says "several hours at lower temperatures is not equivalent to using the specified requirements," and the earlier text explains why: the moisture is chemically bound to the coating, and those bonds have to be broken at the proper temperature.
• Treating 800 F as safe for everything. It is the top of the envelope and 225 F above Hobart's 418 figure.

One secondary guide, Welders Supply's E7018 page, says Lincoln Excalibur rods call for 700 to 800 F. Lincoln's own table does not support that for E7018. In Lincoln's sheet, 700 to 800 F (370 to 430 C) is the row for E8018, E9018, E10018 and E11018, and the earlier Lincoln text gives the same 700 to 800 F for low-alloy rods under AWS A5.5. Where a guide and the maker's table disagree, the table wins.

How to redry correctly

The temperature is half the procedure. The rest comes from the same Lincoln documents.

1. Take the rods out of the can. The earlier Lincoln text says not to put the can in the oven: "the cardboard liners can char, and the temperature of the electrodes will not be uniform."
2. Spread them out. Lincoln's current sheet: rods "should be removed from the can and spread out in the oven because each electrode must reach the drying temperature." A tight bundle has a cold core.
3. Start low. The earlier text says the oven should be at no more than half the redry temperature when the rods go in, held there for half an hour, then brought up to the final temperature.
4. Pre-dry wet rods. For rods that contacted water or sat in high humidity, Lincoln's table adds a pre-dry at 180 to 220 F (80 to 105 C) for 1 to 2 hours before the final temperature, to "minimize the tendency for coating cracks."
5. One hour at the final temperature. That is Lincoln's figure and Hobart 418's. Hobart 718 says one to two hours.
6. Move them straight to the holding oven. A redried rod that cools on the bench starts its exposure clock again.

Lincoln limits E8018 and stronger rods to no more than three one-hour redries at 700 to 800 F, because repeated heating can oxidize alloys in the coating and lower tensile or impact properties. It does not print a count for E7018. Its discard rule applies to every low-hydrogen rod: throw it out if the coating becomes fragile and flakes or breaks off while welding, or if the arc changes, "such as insufficient arc force."

Which oven does which job

This is the gap most shops fall into. Rod Ovens sells stick electrode ovens in three classes, and their maximum temperatures line up against the figures above like this:

A holding oven tops out at 550 F, below every specific E7018 redry figure on this page. It falls inside the generic 500 to 800 F envelope, which is exactly why people assume it can redry. For Lincoln and Hobart 418 rods, it cannot. A holding oven keeps dry rods dry. Only a rebake oven puts over-exposed rods back to spec.

The same check applies to any oven you are thinking of borrowing. If it cannot hold 650 F for an hour, it cannot redry Lincoln E7018, and running it cooler for longer does not make up the difference.

Storing 7018 in a home shop without an oven

Most home shops have no holding oven and burn a few rods at a time, weeks apart. Here is what the alternatives actually do, measured against the figures above.

Sealed tube with desiccant. A gasketed rod tube or a capped pipe with a charge of dry silica gel holds the rods in low-humidity air between sessions. The rate of moisture pickup depends on relative humidity, so this slows the clock. It does not reverse it. Silica gel adsorbs water from the air around the rods. It cannot pull out moisture already bound into the coating, which takes the redry temperature. The desiccant also saturates, and needs regenerating at low oven heat, about 250 F (120 C) for silica gel, as covered under desiccant sizing and regeneration. A sealed tube without fresh desiccant just traps whatever humid air was in it when you closed it, the same mechanism that rusts tools in a gasketed box that was sealed while damp.

Heated cabinet at 100 to 120 F. A light-bulb or low-wattage cabinet heater is the setup Lincoln specifies for opened non-low-hydrogen rods, 100 to 120 F (40 to 50 C), for types like E6010 and E7014. It keeps the rods warmer than the room, so they stay above the dew point. It is not a 7018 holding oven, which runs more than twice as hot, and like the tube it cannot dry a rod.

Leaving them in the opened can. This is the worst option. The can no longer seals, the cardboard liner holds moisture, and the rods sit at shop humidity indefinitely.

A workable routine for general fabrication on mild steel, without an oven:

• Buy the smallest hermetically sealed package you will use, so less of it sits open.
• At each session, take out only what you will burn within the exposure limit: about 4 hours for standard E7018, up to 9 for H4R or MR rods.
• Put the rest back in the tube with regenerated silica gel the moment you are done. Use indicating gel so you can see when it is spent.
• Mark the tube with the date the can was opened and a running tally of hours out. When that tally passes the exposure limit, the rods are, by the manufacturer's definition, due for a redry.
• Keep the tube in the shop's consumables zone near the welder, off the floor and away from the wet and dirty end of the room, as laid out in garage shop zoning. Not in a truck box, where daily temperature swings drive condensation inside the box.

If you settle on a dedicated cabinet for rods, wire and flux, give it a place on the wall rather than a corner of the floor. Wall position is covered in the shop wall system comparison.

Where the home routine stops being good enough

The tube-and-desiccant approach is a compromise, and it has hard edges. Move to a holding oven, and a rebake oven or fresh sealed rods for redrying, when any of these apply:

The honest framing: for non-critical work on mild steel, slightly damp 7018 still makes a weld, and a disciplined tube routine keeps the rods well inside the range where that is true. The moment the work has to meet a standard, or the steel is strong enough to crack, the question is no longer how well you stored the rods but whether you can show they were held at 250 to 300 F and redried to the maker's figure. Without an oven, you cannot.

For a small shop that welds code work only occasionally, the cheapest compliant answer is often not an oven at all. Open a fresh sealed can for the job, hold what you need in a portable oven at 250 to 300 F while you work, and treat the leftovers as general-purpose rod from then on. A portable oven needs a live outlet within reach of the machine, which is one more argument for a welding cart with properly integrated power.