Stick welding which is also known as Shielded Metal Arc Welding (SMAW) uses an electrode with fixed dimensions along with a power source for joining different kinds of metals.
What is Stick Welding?
This process generates the heat through an application of electric current. The electrode is consumed in this process while the coated flux on it, covers the molten weld to protect it from the environment. An electric arc which is generated between the metal and electrode gets either DC or AC from the power source. The temperature can be up to 7000 degrees Fahrenheit.
How to Stick Weld?
This process is one of the most used and famous processes in the industry. The easy use and simple techniques make it favorable for the number of applications. Especially for maintenance and repair demands – stick welding is preferred.
However, SMAW is also widely used in fabrication and steel industry. Metals like Nickel, Chrome, Copper and Steel family can be welded through this gas shielded technique.
The metal surface and electrode both becomes molten in the process of heat that eventually cools to become a joint. Just after providing the power supply, the flux covering the electrode erupts out from its surface and act as a shielding gas to cover the molten pool through a layer of slag.
The voltage range is between 15 to 40 Volts. However, how much voltage is to be given? This depends on the perimeter of the flux coated electrode.
The relative amperes are normally 30 to 500 amps. Whatever is the range; the power source should have the regular or digital control to adjust the voltage as per the demands of metal or the environment or in sudden changes that usually occur during the high temperatures processes.
Apart from providing cover to the molten weld; the shielding gas also helps to maintain the stability of arc. Without the proper protection of flux, the chemical, metallurgical properties, and internal structure can’t be achieved according to the prevalent standards.
- The equipment especially the coated electrodes and associated power does not cost much and helps to achieve the economic edge.
- Some industries are situated in the areas where the wind speed hinders the maintenance process. However, stick welding does not get affected by the environmental ups and downs.
- This process can be applied to almost all the metal and alloys in the common use of industry and public.
Among all the available techniques, SMAW is the most versatile with respect to its use in difficult locations and environments. In production lines, water refining plants, oil refineries, and pipelines – in all these fields, stick welding helps the welders to perform their task with ease and concentration without caring much about the equipment and accuracy.
- In some cases, the rate of deposited weld metal is high which is not favorable for the latter application of the welded metal.
- The level of manual operation is high and it is difficult to induce the mechanical or automated aspect. This makes it difficult to co-opt with the automatic process.
Shield metal welding can’t be applied to the reactive materials e.g. Zirconium and Columbium for their reactive nature. The reason behind is the gases in shielding, which may react with the above-stated materials.
Some Stick Welding Tips
How to deal with common mistakes
This process is manual usually and the common defects while performing SMAW are porosity, hole and uneven structure of the weld. The weld angle greatly affects the final shape.
The variation of voltage and required amperes changes the shape of a weld. High or low current, changes the dimension as with high current – the bead would be wide and spatter would cause the distortion along the weld line.
In case of low current – the bead will be narrow than the required size and the penetration would be inadequate and not conforming to the requirements.
Speed of the weld
While performing SMAW – welder should be careful with speed as more than required speed would cause irregular structure. The reverse will be expected in case of less speed (the bead will be convex shaped).
Weld Angle and Slag
The angle should be according to the recommended practice otherwise the slag cover will be disturbed and consequently leading to unwanted results.
In case, slag is removed easily, this shows a smooth and standard completion of the process while any difficulty shows the irregularity in the final structure and the process.
The Length of Arc
The work distance greatly determines the quality and shape of the weld bead. As with increasing length of arc and risen voltage would result in spatter and widen weld.
In case of less distance, the voltage will be dropped resulted in the convex look of the bead.
In order to avoid these circumstances, there should be adequate distance so that consistent weld with sound metallurgical structure could be obtained.
These are some of the things that should be cared of while performing the stick welding.
Safety Measures for a Stick Welder
In addition to above-mentioned care, one vital factor is the PPE (Personal Protection Equipment). Use of proper welding helmet, gloves and goggles is compulsory. Safety tops the chart of preferences in all welding tasks.
Also, maintain a position from heat work for any sudden explosion. Some metals could react in an unusual way in the presence of contamination (if any).