Today, the welding machine has become the irreplaceable equipment for beginners and professionals. Different types of welding machines allow performing various operations, ranging from domestic work to complex projects.
Many DIY enthusiasts don’t know how to choose the welding machine that will meet their needs. If you are one of those people who want to try their hand at welding but don’t know where to start, this guide will be handy.
Specifications of Electrode Welding Machines
Depending on the welding technique you choose, you may need different types of electrodes. Thus, manual arc welding uses a replaceable rod electrode. In gas-shielded welding (MIG/MAG), a motor is used to feed a wire filler material from a roll through a hose to the welding gun. At the end of the welding gun is the contact tip, through which the wire is fed. In TIG welding, a non-consumable electrode is used.
Before buying the welding machine, you should get a clear idea of what jobs it will tackle and which specifications it should have. Take the following specifications into account:
- It should have a dual voltage input (110V/220V or 115V/230V).
- There should be an adjustable output current (20-160 Amp).
- Multifunction TIG/MIG/ARC welding is a plus.
- The working temperature should be 14℉-104℉. The duty cycle at 77℉ shouldn’t be less than 40% and the duty cycle at 104℉ shouldn’t be less than 30%.
- Ingress protection (IP) grade should be minimum IP21 (2 – protection against solids, 1 – protection against liquids). In this case, the digit “2” indicates protection against objects whose size is more than 12.5 mm. The second number indicates protection against the ingress of moisture. The digit “1” is the minimum protection against water droplets that fall vertically if the welding machine is installed in a horizontal position.
- The electrical insulation system determines the maximum hot-spot temperature allowed. Usually, this is the insulation class “F”, which means that the maximum hot-spot temperature allowed is 311 °F.
Types of Welding Rods
For amateurs, it can be difficult to figure out which electrode to use and what specifications to consider. There are so many questions that beginners face, so this FAQ section will help you clarify some issues.
- What is a welding rod?
The welding rod is a coated metal wire. Electrodes can be consumable (they melt, they are used in shielded metal arc welding) and non-consumable (they do not melt during welding, they are used in TIG welding).
- What do the numbers on a welding rod mean?
As a rule, a number on the welding rod consists of a prefix and four or five digits.
For instance, the electrode used for welding a mild steel joint has the following number format – E6011.
The prefix “E” means a consumable type of an electrode. The first two digits (60) mean that the minimum tensile strength of the filler material is 60,000 pounds per square inch (psi). If there is a five-digit number, then the first three digits indicate the minimum tensile strength (e.g. the digit “100” means that the tensile strength is 100,000 psi). The next digit (1) indicates the position the rod can be used in. In this case, the digit “1” means that the electrode can be used in all positions.
The last digit (1) shows the type of coating and current.
0 – High Cellulose Sodium – (DC+)
1 – High Cellulose Potassium – (AC, DC+, DC-)
2 – High Titania Sodium – (AC, DC-)
3 – High Titania Potassium – (AC, DC+, DC-)
4 – Iron Powder, Titania – (AC, DC+, DC-)
5 – Low Hydrogen Sodium – (DC+)
6 – Low Hydrogen Potassium – (AC, DC+)
7 – High Iron Oxide, Iron Powder – (AC, DC+, DC-)
8 – Low Hydrogen Potassium, Iron Powder – (AC, DC+, DC-)
- What are welding rods made of?
Consumable and non-consumable electrodes can be with or without coating. Usually, the coating is a 1-3 mm layer that forms from 15% to 30% of the total electrode weight. Rods with the coating are more effective because they provide numerous advantages, including arc stabilization and the creation of a protective atmosphere.
Consumable electrodes have a thin coating. Shielded arc electrodes have a heavy coating (this coating can consist of organic materials, e.g. cellulose, mineral substances, binders (simple or complex silicates of sodium, potassium, and lithium), or a combination of cellulose and minerals).
Non-consumable welding rods can be of two types. The first type of welding rods is made of carbon graphite (in some cases, there is copper coating). Usually, these electrodes are used for both welding and cutting.
The second type includes electrodes, used in TIG welding. They can be made of pure tungsten, tungsten with 1% thorium, tungsten with 2% thorium. Besides, there can be tungsten electrodes that contain 0.3-0.5% zirconium.