Tap to Read ➤

How to Arc Weld

Shrinivas Kanade Dec 1, 2018
Arc welding is extensively used for numerous applications with very good results. Let's learn more about this process.
Arc welding is a technique used to weld or join objects that are made up of metals such as stainless steel, aluminum, cast irons, etc. The welder works by using an electric current that passes through an electrode to heat, melt, and fuse together the edges of the metal in question.

Methods of Arc Welding Metals

There are some arc welding processes, wherein the metal of the electrode in itself melts to form the weld. Let's have a look into these.

Arc Welding Stainless Steel

One can use this to repair household items such as a cracked sink or a grain bin. While welding following safety precautions such as wearing welding helmet, leather gloves, and other related items to ensure personal safety is essential.
If you are new to this procedure, it will be beneficial to rent a Shielded Metal Arc Welding (SMAW) rather than buying it. Visit a hardware store or a equipment rental agency in your locality for this purpose, and also select pliers, a welding hammer, AWS E308 stick electrode, and a wire brush along with it.
SMAW is used to weld rusted metal, thin paint, and oils. It can be used in windy weather conditions, as it does not use a shielding gas. The base metal and the electrode thinness affects the weld quality.

To use this welder, plug it into a power outlet.

See to it that you properly connect the ground cord and the welder-electrode holder cord into the welder.
Prepare the surface of the stainless steel to weld with the help of the wire brush.

Attach the grounding clamp cord from the welding machine to the steel with the help of a clamp.

Secure an electrode into the welder-electrode holder, and lay it close by the stainless steel to weld. Put on your helmet to protect your face and eyes.
You can strike an electric arc to melt and weld the metal by tapping the electrode on it. The tapping action completes the electrical circuit, and when you pull the electrode half a centimeter or less away from the metal, it produces an electric arc.
Start welding together the steel pieces by weaving the electrode from side to side, and maintain the required distance to sustain the arc.

After a minute, let the weld cool by using a hammer to chip off the slag (a coating left by the electrode on the weld) from the top of the weld.

Arc Welding Sheet Metal

Using SMAW, one can weld in a wide range of conditions and applications. For welding sheet metal using 3/32-inch, a 6011 stick electrode is useful.
Set the welder to AC or DC positive, and maintain the current at 60 amps. Depending on the thickness of the metal and welding-style, you may need to change the amperage needed for the procedure.

Attach the welder to the holder, and take precautions for personal safety.

Touch the tip of the electrode to the metal, and start a welding arc.
Start working on the welding joint, and maintain the electrode about one-eighth inch above the sheet metal. Push the molten weld puddle along the joint to be made.

After finishing the weld, chip the slag from the weld with the hammer, and clean it with a wire brush.
Only after two or three hours, when you are sure that the joint has cooled sufficiently, think about moving the welded metal.

Arc Welding Cast Iron

Cast iron is difficult to weld even for an experienced welder, because of its properties of expansion and contraction. It is a skill in demand, as it has numerous applications in strength-required welding jobs, such as support beams and base brackets.
For this job, you will need nickel welding rods, which are also referred to as Softweld 55 Ni.

Brush clean all the areas to be welded, and one can even clean with a grinder. The area where the grounding rod is to be attached to the metal needs to be properly cleaned.
Attach the grounding clamp to the metal, and maintain the arc welder at the lowest possible setting; increase the current depending on the thickness of the cast iron.

Welding cast iron is a tricky job best done one inch at a time. Let the metal cool after each stop, to about 100 degrees Fahrenheit. Before resuming the welding, chip off the slag from the weld.

Welding Thin Metal

Arc welding thin metals is difficult as one can accidentally burn through them, rather than create a firm weld, and hence spoil the job. This happens because of the high temperature that arc welders are designed to produce during the welding.
Clean the area of the metal to weld with a wire brush, as the dirty metals can cause faulty welding.

By keeping the electrode centered on the weld puddle, one can prevent thin metals from the full force of the arc.
Move the electrode along the joint in a straight line rather than from side to side, during the welding process. This will help in preventing metal from over heating

Weld as fast as possible. Maintain proper weld pool between the two metal pieces.

One can prevent overheating the metal and achieve a quality weld by welding an inch and skipping some distance.

Vertical Arc Welding

Executing in an vertical manner as well as angled, welding is difficult because the person has to counteract the gravitational force that acts on the molten metal, and tries to pull it downward.
The solution is to weld vertically downwards, starting at the top of the weld by holding the electrode that is pointing up at 15 degrees to the horizon.

This helps in using the pull of gravity to finish the welding rapidly.

This method is best for welding thin metals.

Arc Welding Aluminum

Gas Tungsten Arc Welder (GTAW), also referred to as Tungsten Inert Gas (TIG) welding, is the most commonly used equipment to weld aluminum.
This metal has low melting point than steel. Aluminum sheets of 1/8 inch thickness can be firmly weld together by using a 115-volt arc welder.

A 230 Volt machine can be used to weld aluminum pieces that are up to ΒΌ inch thick.