Flux Core Wire Feed Welding Procedures

Electrodes

• The wire or electrode the machine feeds out when welding is called the electrode. It has an outer shell made of metal surrounding a core made of "flux," a substance intended to shield the nascent weld from the oxygen in its immediate surroundings. You can purchase electrodes in one of several standard sizes: 0.035, 0.045, 0.052 and 1/16 inches. The electrode you use for flux core welding is different from the electrodes you would purchase for MIG welding.

Types

• The electrodes also come with a code to indicate the type. These codes always begin with the letter E for electrode, followed by a single digit indicating the amount of tensile strength in 10,000 pounds per square inch. Next you'll find another digit that will be either a 0 or a 1; a 0 electrode can only be welded in a horizontal position, while a 1 can be welded in any position. T indicates a flux core electrode, and the final number designates the type of flux.

Feed & Transfer

• The welding machine can use either a globular transfer or a spray transfer. The former uses a dual-shielding electrode; the later does not. Spray transfer is the more common of the two. The rollers that feed the wire through the machine must also be set to the right tension -- just tight enough to feed the wire, but not so tight they crush it. The voltage and feed speed are the other two important settings on the machine, and these are quite critical.

Settings

• A faster feed speed creates a higher current and thus more heat. Too fast and too slow are both undesirable. Most welding machines come with a chart that lists recommended speed and voltage combinations, although many welders prefer to use the manufacturer-recommended voltage while choosing the feed speed on the basis of experience rather than chart recommendations. When the settings have been chosen properly, the weld should make a deep, fast crackling sound.