Factors Affecting the Feedability of Aluminum Electrode

Feedability of Aluminum Electrode: Significance of GMAW Equipment and Accessories 

The performance of GMAW equipment used for welding aluminum significantly affects electrode feedability. Arcing or burn-backs are often the result of deficiencies in accessory equipment. Such deficiencies can be attributed to improper combinations of accessories and poor care or lack of preventive maintenance. Correcting these deficiencies often improves electrode feedability markedly. Shown above are important accessory components, each of which must be the manufacturer’s recommended equipment for the specific size of electrode employed.

Functions and Maintenance of Accessory Equipment:

Drive Rolls

In addition to proper U-type drive roll contours, correct drive roll pressure must be maintained. Excessive drive roll pressure distorts the electrode increasing frictional drag through the liner and contact tip. The edges of the U-groove must be chamfered, not sharp.

Dust Covers

Using dust covers and periodically cleaning the dust and dirt from the liner increases service life. Proper storage is also important in reducing contamination. AlcoTec recommends storing the electrodes in a controlled atmosphere below thirty percent relative humidity, preferably a temperature and humidity-controlled cabinet. Packages containing electrodes should never be left outdoors or stored in unheated buildings. Electrode should never be left in equipment overnight unless protective means are added to the equipment, such as gas purge, resistance heater, etc.

Contact Tips

Correct I.D. of the contact tip is of paramount importance. Arcing will occur if there is too much clearance between the electrode and the contact tip. Continuous arcing causes a buildup of particles on the I.D. surface of the tip, increasing the drag force and producing burn backs due to unsteady feed. Deburring and polishing new contact tips and repolishing or changing contact tips when unsteady feeding is noted also improves overall performance.

Conduit

Properly sized flexible conduit with teflon, nylon, or plastic liners improves the feeding of electrodes through long distances by avoiding abrasion of the electrode. Non-metallic connection fittings also ensure smooth feeding, which should be checked periodically.

Achieving High-Quality Welds

Although welding equipment is sturdy, the abuses of day-to-day work make regular maintenance important. Faulty or improperly maintained welding equipment can result in poor welding work. Nevertheless, with the proper selection of welding parameters, correct equipment and accessories, an effective program of preventive maintenance, and the purchase of AlcoTec Almigweld electrodes, high-quality welds are attainable.