Arc Welding

The arc welding process or the stick welding process uses a simple electrical circuit to melt the welding electrode, burn the flux and melt it all together with the base metal that you are welding. This can be seen in the diagram below.   Now the flux that burns off the rod does not actually mix in with the molten metal, but it sits and floats to the top. This can be seen on the diagram above as the "green" coloured layer that is sitting on the weld bead. If the slag gets into the weld bead you can get what's called "slag inclusions" and pin holes and other defects in your welds. Arc welding with AC or DC  You can stick weld using alternating current or direct current. Using a machine that has an AC, alternating current output is very common as there are lots of these machines in the world today. But just so that you know amig welder is usually DC output. It is cheaper and easier to make a simple alernating current welding machine than it is to make a DC output machine. Although, times are changing and there are a lot of newer machines out there that are inverter driven and have the capabilities to do both AC or DC output. If you use a DC or direct current machine you can choose which way you want the polarity to be. You can have the welding rod positive or negative. And this can be changed easily using a rotary switch on the front of the arc welding machine or by switching over the welding cables. Some welding rods will only work with AC power. And some are only designed to work with DC power. It all depends on the welding application.

Constant Current Machines

 The arc welding machine is also what is called a constant current machine. This means that the current output is set by the initial power setting on the machine. Voltage is adjusted by how big an arc there is at the end of the electrode. The bigger the arc the higher the voltage, the smaller the arc the lower the voltage. This is called the "arc length". The arc voltage has a direct impact on the heat being made. So it is important when you are welding that you keep you hands, arm and body steady and travel smoothly when stick welding.

Manual Metal Arc Welding Machines

From small DIY home hobby arc welding machines right up to large three phase industrial units. The arc welder has earned a reputation for versability and durability throughout the world. Some of the benefits of using an arc welder are:

1. Cheap and available everywhere.
2. Portable, even more so now with the little inverter arc welders.
3. Can be used outdoors in windy conditions.
4. Robust and last for ever. No mechanical components to replace, except fan.
5. No need cart around a gas bottle.

Who uses an arc welding machine?

From small DIY home hobby machines right up to large three phase industrial units. The arc welder has earned a reputation for versability and durability throughout the world.  They are used on just about evey farm to repair tractors and farm machinery. Qualified welders and boilermakers use them for pipe welding.  And the average person uses a stick welding machine to make basic repairs, and projects around the house.

For the electric arc welding process to work you need.

1. Electricity, either AC or DC.

Most arc welding machines are AC output. Plug it into the wall socket (120v AC, 220-240v AC) and the electricity goes through a transformer, and is "transformed" down lower voltage suitable for welding with. Chances are the small machine you have a home in the shed will be a AC output.

2. You need an electrode to burn.

The electrode is what melts down into molten metal and fuses to the base metal.

3. And you need to make a basic electrical circuit.

Clamp the earth lead to the base metal, touch the electrode to base metal to complete the circuit.

When the rod touches the "earthed" base metal. The electrode will spark up generating high amounts of heat. This heat will melt the electrode, and also the base metal. As the electrode melts the molten metal will attach itself to the base metal, forming a weld deposit.

Simple as that

Now, you can't just grab a bit of fencing wire and hook it up as an electrode and weld. It will not work. Why?.... All welding electrodes have what is called a flux coating on the outside of the rod. This flux coating burns and creates a "shield" to keep unwanted gases out.  Unwanted gases are in the air we breath. This is why the techincal name for arc welding is " Shielded Metal Arc Welding" or "manula metal arc welding"..

Now you need to learn how to use it.........Arc welding is not rocket science. It's simple, fun and easy to do, providing that you learn a few basic techniques from the start.

Other ARC welding links of Interest

How to ARC Weld

Here are some simple steps and instructions for how to arc weld. Hopefully I have made these easy enough for you to follow through and get a good idea and a good start to using a stick welder.

Lets take a look at an   ARC welder and find out the basics of what they are and how to set one up. In the video we take a look at a small AC stick welding machine that is the type of machine that you can get from any hardware store or auto shop in town.

Return from ARC welding to home.