In stick welding we use a rod (welding electrode rod)
covered with flux. It was discovered in WWII that coatings on the filler rod made
it weld better. On ships and other production sites, bare metal rods were used
usually in the flat position. Rods were stored out in the open and not much care
was taken with them.
One day some guy in a hurry grabs a rod that's been
left out and is covered with rust. Next thing he knows, it is welding better than
a brand new clean one. After experimenting with various coatings of silica, cellulose,
sodium and other elements it was found that putting a flux coating on the filler
rod produced a very sound weld.
Click here to view our Electrode Rod Storage Ovens!
Flux burns and turns into a shielding gas
that protects the weld pool from atmospheric contaminants such as hydrogen, nitrogen,
oxygen and others. These contaminants get into the weld pool and cause defects
such as cracking, and porosity (worm holes.) These defects create a weak point
where the weld can fail under stress or load. To keep that from happening, rods
should always be stored properly.
What happens, especially in low-hydrogen
rods, is moisture gets into the flux. Low-hydrogen rods are just what their name
low hydrogen. They need to be kept dry or porosity will be introduced
into the weld bead. This will happen at the beginning of the bead with each new
rod used, and diminish as the rod heats up and burns the moisture out as it is
Many job sites and shops do not use proper electrode storagae and
moisture gets into the flux. This moisture turns into steam and leaves small bubbles
in the weld pool which leaves holes.
Rods need to be stored in hermetically
sealed boxes in a vacuum. Once the box is open, humidity in the air will enter
the rod flux, so something must be done to keep this from happening. Too many
people use methods they have heard from other welders which do not work. It's
almost like old wives' tales, the stories out there.
Improper Electrode Rod Storage
Some say proper rod
storage is wrapping the rods in plastic and putting them in the freezer. Others
say get an old refrigerator and put a light bulb in it. The only correct method
of storing rods properly is to put them in an approved rod oven.
rod oven will keep the rods at their manufacturer-rated storage temperature, and
can be used to re-bake the rods after they have been exposed to atmospheric moisture.
Although E-XX10, 11, 12, & 13 rods can be stored in dry boxes at room
temperature, most other rods are recommended to be stored at anywhere from 150
to 400 degrees Fahrenheit.
That's why the refrigerator with a light bulb
is not good for electrode storage. It will not achieve 400 degrees, and the light bulb
is not going to create uniform heat throughout the inside. The heat needs to be
consistent and that is achieved with a professional oven whether portable, floor