Trouble Shooting Exothermic Electrodes.
Oxy-arc cutting, especially exothermic cutting relies on an unobstructed oxygen flow to be most effective. With inadequate oxygen flow, the rod will burn but not produce the desired cutting effect. Since the actual cutting result is derived from the volume of oxygen reaching the target, any restriction in oxygen flow will decrease efficiency.
Symptoms. The following are indications of an oxygen-delivery problem:
a. Oxygen jet at electrode tip less than 6 inches.
b. Electrode burns down in approximately 60 seconds of continuous use and cuts less than 12 inches of 1/2-inch plate.
Probable causes. The following are possible causes to an oxygen flow problem:
a. Regulator incapable of delivering 70 cfm.
b. Torch incapable of delivering sufficient flow. Older torches; those designed for 5/16inch
electrodes will not flow sufficient oxygen volume.
c. Torch obstruction, such as dirt in oxygen passage, a damaged flashback arrestor,
clogged or burnt monel screen or a damaged oxygen flow valve.
d. Oxygen hose too small, using 1/4- or 5/16-inch hose or a clogged or obstructed 3/8inch
In all the above cases the regulator pressure will appear normal. There simply is not enough oxygen
volume to allow the electrode to cut properly.