Welding Different Thickness Metals. For instance when welding aluminum the heat dissipates much more quickly than if you were welding something like mild steel. The Type of Gas You Use.
The same electrode which works well for a thin piece of steel would not be as useful when welding a thicker piece of steel. Stick welders work best on thicker metals and are not a good choice for thin sheet metals. HAZ sizes are influence by several factors such as heat input welding traveling and metal thicknesses.
Otherwise you run the great risk of insufficient heat to securely weld to thick material creating likelihood of failure.
0030-inch diameter is the most commonly used wire due to its versatility dealing with various thickness of metals. Stick welders work best on thicker metals and are not a good choice for thin sheet metals. Before welding I set my inverter welder to 150 amps output pulse rate at 200 and clamped 18 x 34 copper bars behind the sheet metal. They are excellent for fabrication of structural steel fixing farm equipment tractor repairs ship building power plant construction welding pipe and any metal 116 or thicker.