ALUMINUM WELDING GUIDELINES FOR THE RWII
When welding aluminum, be sure to use a contact tip which is .005” larger than the wire diameter itself and extending the nozzle out approximately 3/8 of an inch. Recessing the tip helps reduce burn back (ie. melting the wire to the tip). Because aluminum conducts heat so rapidly, some users find it preferable to increase the wire feed speed and move the bead more quickly across the metal being welded than with steel, especially on thin aluminum of 1/8th inch and less. Please consult the Chart on page 15. Preheating aluminum over 1/4’’ to approximately 250 degrees F., is a widely recognized practice and helps on the start of the bead while increasing the penetration. Using a heat sink (ie. steel plate) on thin aluminum will help prevent burn through, also quenching thin aluminum with water will help keep the metal from over heating. When welding thin aluminum it will help to reduce the voltage and amperage. See thin metal guidelines on page 5. Also on 1/8’’ metal thickness or less the travel rate must be faster then on steel and similar to drawing a line on a piece of paper. Having extra contact tips is highly advisable. When the wire speed is adjusted correctly there should be no splatter and the weld process should be very quiet, similar to the sound of a gas leak. The proper travel is to push with aluminum, usually right to left.
OPERATION
Duty Cycle
Unlike conventional welders, which are limited in how long they can weld because of heat build-up, the RWII has a 100% duty cycle when shielding gas is being used. Use of flux-core wire with high amperage levels may require cooling periods. The welder can be cooled rapidly with compressed air. When operating from direct cur-rent drawn from batteries, there are no power source components to overheat. The system can be operated con-tinuously for as long as the batteries deliver power. Leave a small space between the nozzle and the face of the gun so as to not transfer heat directly into the plastic.
Using the MIG Gun
RWII can use any of a number of types and sizes of welding wire, as shown in the Application Chart on page 15. One of the major advantages of RWII is the ability to control the speed of the wire directly from the gun. Wire speeds can range from 49 inches per minute for lighter work to 900 inches per minute for heavier metals. Speed selection is done using the speed selector knob. The Application Chart lists applications for various metals that can be welded with RWII, including recommendations for wire, gas tips, and various system settings to be used for different applications.
RWII CONNECTIONS
BATTERIES
Batteries make an excellent power source for welding, as this is pure DC power. Two 12 volt batteries connected in series at 24 volts DC will pull approximately 275 amps of power with .045 wire to single pass up to 1/2 inch plate. At 36 volts DC the RWII will pull approximately 350 to 400 amps. The RWII will under the correct circumstances makes an ideal thin metal welder using 12 volts. Larger wire has less resistance so at 12 volts the RWII should be able to weld 18 to 24 gage metal using .035 wire. The opposite is the rule for 24 volt power as smaller wire down to .023 will increase the resistance to help reduce the output power. By adjusting the gas mixture and voltage, the RWII will adjust to spray transfer. Deep cycle marine batteries have a longer discharge/recharge life over standard batteries. However welding performance will be the same with either type of battery.
MODEL 10000
Connect two 12volt batteries in series by connecting the positive terminal of battery #1 to the negative terminal of battery #2. This set up provides the necessary 24 volts. For all gas shielded wires use reverse polarity (green light). Connect the lead (gun) to the positive terminal on battery #2 and the ground to the negative terminal of battery #1. Again the green polarity light indicates proper reverse polarity. For flux core, self-shielded, wire use straight polarity (red light) with the gun lead connected to the negative terminal of battery #1and the ground connected to the positive terminal of battery #2. See illustration on page 10.