GET YOUR SETTINGS RIGHT
PREPARE TEST PIECES
Make life easy for yourself by starting out on 3-5mm mild steel cut into handsized rectangles. Avoid rusty scrap or really thin metal, or you’ll give up before you start. Clean off any mill scale with a flap disc in an angle grinder and degrease it thoroughly.
Many modern sets have synergic controls. Some can work out the voltage and wire speed if you tell them the material thickness, wire diameter and gas type. Others maintain a predetermined relationship between voltage and wire speed.
A good earth is essential for a good weld. If you have a cheap welder with a jumper lead-style clamp, it’s worth investing in a more robust type. Place the clamp as near to the weld as possible. Copper strands will increase the contact area.
FIND A BASIC SETTING
Begin tuning-in your set with the voltage too low and the wire speed too high. It’ll look and sound nasty, but it’s a start. As you get used to your set, you’ll get better at predicting settings. Some sets come with handy charts to calculate basic settings.
VOLTAGE AND WIRE SPEED
All sets are different, but at the heart there will be two main controls: voltage and wire speed. A good weld relies on their correct relationship. Some sets have knobs; others buttons. The controls are rarely marked in actual volts or metres/min.
Turn on the set, gas and shield. Hold the torch in one hand with your forefinger on the trigger. Steady the torch with your other hand. Hold the torch’s contact tip 9-12mm from the surface at the angle shown. Pull the trigger for a few seconds.