Vertical and overhead stick welding have never been so popular.Flat and horizontal are the fastest welding positions to use, but when vertical or overhead welding with a stick electrode cannot be avoided, doing it well requires attention to several considerations
First, choose the right electrode
Fighting gravity is the main concern in vertical-up welding—or with any position that is 45 degrees or steeper. Stick electrodes with an American Welding Society (AWS) classification of 7018 are considered the first choice because of their lower iron powder content.The molten metal produces a puddle that can freeze quickly and is less inclined to drip off the work during its liquid state. AWS 6010 also can be used for similar reasons, but 7018 enables a faster weaving pattern. Using 6010 requires a stacking or a whipping technique, where the stick is intermittently pulled in and out of the puddle.
A 6010 electrode will help overcome poor surface conditions, but using it takes more time and skill than weaving with 7018. Those new to vertical-up welding sometimes mistakenly choose a 7024, which lacks proper fill and often drips uncontrollably down the work.
Next, create a “weld shelf”
Of the five welding positions—flat, horizontal, overhead, vertical-up, and vertical-down—vertical-up is the slowest because the welder needs to combat gravity. A slow travel speed provides
Vertical and overhead stick welding skills are in greater demand than ever before.
Whip your stick.jpg
Vertical or overhead stick welding requires mastery of several new techniques and selection of the right stick material, such as AWS 7018, which allows a faster weaving pattern on fillet (top) and butt welds (bottom).
better penetration than vertical-down, so the technique is required on most material heavier than sheet metal.The trick to both vertical and overhead welding is preventing the puddle from spilling out of the weld. For material heavier than sheet metal, vertical welding generally should be performed uphill. Welding sheet metal can be performed downhill because less penetration is needed, and the faster travel speed produces cooler temperatures that prevent burn-through.
Vertical-up can be compared to bricklaying in that the welder slowly creates a weld base from the bottom up, one small section at a time, and continuously works above each previously laid weld. Each newly laid lower weld acts as a base upon which subsequent welds are made. That lower bead is referred to as the “shelf.” Each shelf step should be about 1.5 to 2 times the diameter of the electrode. A 1⁄8-inch electrode would create about a 1⁄6- to ¼-inch puddle needed to freeze in time to uphold the next weld.
When weaving vertical-up with a 7018 electrode, zigzag back and forth and allow each puddle section to freeze in place in time to weld up to the next stair step. Hold the electrode slightly uphill and keep a short arc to gain better penetration and fusion. During a weave, focus on welding the sides of the joint. Pause briefly at the sides to allow the bead below to cool and the lower shelf to form. Watch the puddle closely to allow the slag to drip off the shelf. Slag trapped in the weld will impair strength and diminish appearance. If the base metal overheats, the puddle will spill. If you see this start to happen, quickly move the electrode away from the crater without losing the arc.
With a 6010 electrode, a stacking technique replaces the 7018 weave. The stack should resemble poker chips—each chip creating a shelf for the next level. To stack a vertical-up weld, keep the electrode in the root of the material. As the puddle forms, whip the electrode upward, while maintaining the arc. When the puddle freezes, return the electrode and apply another
level to the leading edge of the weld. Continue until the weld is complete. Again, each puddle should be roughly 1.5 to 2 times the diameter of the electrode.
One error to avoid while weaving is undercutting. This is when the work is gouged without sufficient filler metal, as gravity draws the filler metal away from the work.One way to avoid
this is by reducing current and slowing the process. Sometimes simply reducing the puddle size improves operator control. Better out-of-position welders watch the puddle closely. They learn to read its characteristics. In both weave and stacking techniques, the slag should drip off the shelf, while the puddle forms well enough to fill the gouge and stay in place.
Use low power settings
Because a vertical-up puddle needs to freeze quickly and in place, lower amperage settings are needed to maintain control. Welding in the flat position has the benefit of gravity and can be performed at lower temperatures and faster travel speeds. In general, use the lower end of an electrode’s amperage rating when welding vertical-up or overhead. For instance, power to 120 to 130 amps using 1⁄8-inch 7018 electrodes, and 90 to 100 amps for 1⁄8-inch 6010 electrodes.
Flux-cored welding vertical-up
Flux-cored welding has replaced some of the traditional stick welding in many construction markets because of its faster productivity from a continuously fed wire. But many ironworkers prefer stick, which can be more convenient if the work is shorter in duration. When welding for extended periods in one place, flux cored might be a good alternative. If that’s the case, all the same rules apply as for the vertical-up 7018 stick weaving technique.
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With any out-of-position welding, all of the standard safety precautions for flat horizontal welding should be increased because of the added risk of falling molten metal and spatter. Safety glasses and a proper helmet, gloves,long sleeves, and leather or fire-retardant clothing are a must. Safetytoed shoes will prevent liquid metal from burning through to the skin.
Build a shelf and weave upward slowly enough to allow the level below to freeze while not overheating the base metal Becoming certified to weld in a vertical position is a good idea for anyone planning to do repeated vertical-up welding. Another benefit is that anyone certified in vertical welding is automatically certified in flat horizontal welding.