Welding Basics

Welding is a basic skill that can be useful in a number of situations. Read on to know more about the different types and techniques of welding…

One of the very first attempts at welding by man was called forge welding. It consisted of joining two metals through heating and pounding. From rudimentary metalwork, we have now progressed to underwater welding. Having a basic knowledge of welding can actually come in pretty handy if you are performing any type of welding work, in the house, at your workplace, or even at a farm.

Aluminum Welding

Aluminum is a nightmare for welders. It is considered the most difficult metal to weld, because, in its ore or alloy form, it has various physical and chemical properties that need to be understood in detail before working on it. As it is mixed with many other metals, it is difficult to decide the melting temperature of aluminum. It doesn’t even change color noticeably when its heated, which makes it difficult for the welder to spot it.

Before you start working on its ore form, there are some characteristics about this metal that you should know.

• The melting point of aluminum oxide is higher than its base alloys―3722°F (2050°C).
• It is noticed that hydrogen dissolves in aluminum very easily, but the main problem starts when the aluminum is in its solid stage. Hydrogen cannot gel with solid aluminum.

• If you are planning to do arc welding, aluminum will need a high level of heat, as it is a better conductor of electricity than most other metals. The higher the conduction of electricity, the lower is the heat produced, because the electrodes allow the electricity to pass easily.
• Thermal conductivity of aluminum is six times more than steel, this is because aluminum is more sensitive to heat than other metals.

• The tools required to work with aluminum are TIG welder (Tungsten Inert Gas Welder), a good pair of gloves, and a strong welding helmet. Make sure to wear a long-sleeved cotton shirt, as TIG welding emits UV rays, which can cause burns.
• A mix of argon and helium gas works best with aluminum. Use a steel brush for cleaning.

TIG Welding

It is necessary to know the basics of TIG welding, which can be used for the welding of any type of metal like stainless steel, carbon steel, nickel alloys, aluminum alloys, titanium alloys, etc. TIG welding is also a kind of shielding arc process, which is very similar to MIG welding. The only difference is that the arc is not made of a consumable wire, but of a non-consumable tungsten electrode.

• The instrument for TIG welding should always be a AC/DC welder with a duty cycle of at least 60%. The welder should also have a high frequency generator added in the machine. High frequency is required to keep up a stable arc during the zero-voltage conditions in the current cycle.

• Always buy a branded torch for TIG welding. It will be useful to deliver both shielding gas and electric current to the weld joint. Buy a torch that fits comfortably in your hand. There are many types of torches available, such as air-cooled or water-cooled, which can make TIG welding easy.

Ultrasonic Welding

When you use ultrasonic welding, you apply high-frequency vibrations of an ultrasound to the metals that has to be welded. It puts them under pressure, and holds them together until they join together. Ultrasonic welding is also used for plastic welding and various metals. Let’s have a look at some information on ultrasonic welding.

• When you are using an ultrasonic welding, there is no need of bolts, nails, soldering, or adhesive to keep the materials bound. Vibrations are used on thermoplastics, as plastic is melted due to vibrations of the ultrasonic.
• These vibrations are produced through a welding sonotrode (welding horn).

Flux Wire Welding

Flux wires or flux cores are used by wire-feed welders. The flux is found inside the wire, and gives out a shielding gas when the wire is welded. In flux wire welding there is no need of compressed shielding gas. Flux wire is ideal in windy conditions and is popular for hobbies and farm work. So let’s see some basic information about welding a flux wire.

• Welding solid wires need a shielding gas, which is also called a metal inert gas (MIG). It’s available in a cylinder and is either CO₂ or a mixture of CO₂ and argon. MIG gas offers you a clean weld without any slag and with minimal spatter, and gives you the advantage to weld thinner wires.
• People prefer wire feed welders because they are easy to use and you are able to maintain a safe distance from the welding process, which is absolutely necessary.

• Make sure you use the correct type of wire for the base metal.
• CO₂ is good for welding steel, but is not recommended for thin metals―this is where you use C₂₅ gas (argon 75%/CO₂ 25%). For aluminum welding go for argon.
• Purchase the right kind of wire. Consider the nature of your project, and take into account the nature of your metals.

These were some different tips that can be very useful for both pros and amateurs. Always use branded equipment and the right safety gear while performing any type of welding task.