All about Sheet Metal Welding
Welding is part and parcel of almost all manufacturing processes, as material (after being cut) needs to be joined. However, when the metal sheets are assembled, they are joined together using various methods– sheet metal welding is a common one.
To know more about the different types of sheet metal welding techniques, you must read the guide below.
What is Sheet Metal Welding?
The process of welding sheet metal is a basic one when it comes to joining the metal sheet together. The process involves heating the two metal sheets and then welding them together with the torch. The process is widely used for components used in trucks, ships, aircraft, boats, and appliances.
6 Methods of Sheet Metal Welding
Sheet metal welding is conducted using different methods, and 6 of these methods are discussed below:
MIG Welding
MIG welding is a process of welding sheet metal with the help of an electric arc. The electric arc melts the material and joins the pieces together.
The shielding gas used in the process consists of carbon dioxide and argon. It has a filler material that is fed using a welding gun. The filler material melts and creates a bead on the joint’s end.
TIG Welding
TIG welding uses tungsten in the arc, which creates low vapor pressure and a high melting point. Helium and argon gasses are very commonly used in welding. The filler material creates seamless, and the electric torch helps to weld them by releasing heat.
Stick Welding
Stick welding uses electric current, and due to it, the metal wire is melted and focused. This requires two electrodes and a shield plate, which provides a route for the electric current to follow. Stick welding is very commonly used in steel fabrication, shipbuilding, and construction applications.
Plasma Arc Welding
Plasma arc welding melts the wire with the help of electric current. After the wire is melted, a gas is blown into the molten metal pool, and a plasma is formed, creating a strong arc. The arc heat then lets the base material melt and form a weld. It is used in many industrial applications.
Electron Beam and Laser Welding
Electron beam welding joins the metal sheets with the help of electron beams. The beam melts the filler and creates a weld by joining materials together.
Gas Welding
Gas welding is also a very popular method of welding in which sheets of aluminum, brass, stainless steel, and copper are joined together.
It uses no electricity and offers affordability. Gas welding is suitable for small-sized components like washers, screws, springs, etc. Gas welding needs experience and skills. The process burns the fuels and creates heat to join metals.
Metal Types Used in Sheet Metal Welding
Stainless steel is one of the most common materials for sheet metal welding. However, other materials like carbon steel, gold, and aluminum are even welded. Every metal has its own pros and cons, which are considered when welding them.
- Carbon steel is a cheaper material and is easier to weld; moreover, it offers strength. However, it is not corrosion-resistant.
- Aluminum is also very commonly used for sheet metal welding; it offers corrosion resistance and even is lightweight. But, welding aluminum is difficult.
- Gold has a very high strength and is very expensive, too, but it is also challenging to weld.
Surface to Consider for Sheet Metal Welding Method
When choosing materials and workpieces for sheet metal welding, some of the considerations regarding the surface to make are discussed below:
Flat Surface
Flat welding is suitable for flat surfaces, and when you weld a flat surface, the angle of the point of the torch is at the surface. You can also move the torch back and forth to check if all the sides are melted or not.
Horizontal Surface
On the horizontal surface, the metal sheets offer welders a flat impression. It can take two different forms as follows:
Fillet Weld
Fillet welding is the process in which two surfaces are united at an angle to create a fillet weld. The metal pieces are kept over one another and heated to fuse. After the fusion has taken place, the weld looks like an L-shape.
Groove Weld
A groove weld, on the other hand, is created at the point where the two metal sheets are met at an angle. They are pressed into one another, and a groove is made by welding.
Vertical Surface
When welding the vertical surface, the torch is held at an angle of 45 degrees to the welding sheet. The tip of the electrode is kept away from the molten material so that the metal doesn't stick to it while flowing.
Overhead Surface
Overhead welding is a complicated form of welding because, using the welding process, the metal drops after melting. You can use sufficient filler material to reduce the weld pool and use enough heat to achieve a clean weld.
Practical Tips for Sheet Metal Welding
Some of the essential tips that you must consider during sheet metal welding are given below.
1. Select the Filler Metals
Choose the filler metal which is compatible with the mechanical characteristics of fabrication. It should be thinner compared to the metal sheet. When the wire is thin, the heat requirement is also lower, and hence, clean and high-quality welds are achieved.
2. Use Skip Welding Technique
Skip welding is composed of using short welds at critical points so that the thin sheet is in place. Once cooled down, the other points can be easily welded. It helps to avoid warping and ensures well-finished walls.
3. Use Tack Welding Technique
Tack welding is a method that reduces the risk of heat build-up. These tracks are temporary welds that hold the metal sheet till the final welds are achieved. These tack welds prevent the burning holes, and the metal sheets are aligned properly.
4. Use Small Wire Diameter
During the welding process, the material type is very important. When welding aluminum, you will need a different size of wire, and when welding steel, you need a different size. Hence, based on the material welded, make sure to select the right wire size.
5. Use Small Electrode
The electrode you choose for welding should be thinner compared to the metal. It allows you to come up with an arc that is tighter and even reduces the burn on the sheet metal.
6. Clamp a Backing Bar
The backing bar is meant to take away the heat from the metal, and hence, the risk of warping is reduced. Therefore, clamping a backing bar is suggested for sheet metal welding. These metal bars are mostly made of aluminum or copper and can dissipate heat efficiently.
7. Use High-Argon-Based Shielding Gas
During welding, ensure that the shielding gas you are using has a high amount of argon. A shielding gas that has more argon offers less heat emission.
8. Fit-up and Joint Design
Thinner sheets of metal are very challenging to weld because they need a tight fit-up. Hence, the welders need to be careful with their measurements while cutting the sheets.
9. Adjust Heat
During the process of sheet metal welding, managing heat is very important. If there's a lot of heat during the welding, the metal melts, and it leads to a failure in the joint. Hence, the heat varies based on the metal type.
Conclusion
Sheet metal welding is a prevalent form of welding across many industries and needs to be done carefully. Reading the guide above must have provided you with all the relevant understanding of the process, its types, and tips that are important.
DEK: Your Trusted Sheet Metal Welding Partner
If you are looking to have components manufactured based on your custom requirements using sheet metal welding, DEK can be your service provider. We have a wide range of welding methods offered to cater to every industry and every type of material.
FAQs
Which welding is suitable for thin metals?
TIG welding is one of the most suitable types of welding methods for materials that are thin.
How to weld thin sheet metal?
Welding a thin sheet metal needs high temperatures; hence, heat management and an adequate supply of heat are crucial.
Is TIG or MIG better for sheet metal?
Sheet metal is usually thinner, and hence, TIG offers better welds; however, if the sheets of metal are thick, MIG can be chosen.
Can I use AC or DC to MIG weld aluminum?
MIG welding is a rapid method for welding material, and both AC and DC are suitable for working with aluminum.
