Welding is one of the most important jobs that exist today in society. Welders are often underappreciated, but the work that they do is skilled and requires a great deal of talent and experience.
There are many kinds of welds and techniques that welders can use to ensure the optimal quality of their welding. One of the most beneficial types of welds to ensure quality and alignment is the tack weld.
What Is Tack Welding?
Similar to what the name implies, a tack weld is a small weld about the size of a tack. According to the American Welding Society, Tack welding is described as a joint that holds two or parts in proper alignment until a welder performs the final welding job.
Simply to put it, A tack weld is when multiple pieces of metal are welded together at certain points in order to give a stable, final weld. Tack welding is done without extra tools to hold it in place, and preformed in short welds, usually on the ends and middle.
There is no specific size of a tack weld, however, it is understood that tack welds are small and frequent welds that can be applied to any area of a joint.
Why Use A Tack Weld?
If a welder is doing a large job that will require multiple areas to be welded it can be difficult to keep the entire structure in correct alignment. Tack welds enable a welder, novice and expert, to properly align all the joints before starting the final welding process.
Another great reason to use a tack weld is that they can easily be removed. Therefore, if a welder is applying tack welds to a structure and finds that near the end the pieces do not align properly they can move back through all the joints and remove the tack welds. Tacks welds can be removed before the final welding process, however, final welding jobs can rarely be undone.
Tack welds can also be used to help maintain the joint gap at the right place and value. If a welder is trying to ensure proper joint gaps between structures and areas, it can be hard to eyeball this during the final welding stage. To ensure that everything is set and ready for the final welding a tack weld can be done earlier in the process to ensure everything is set at the right value.
When a structure needs to be moved multiple times during a welding process it can be nearly impossible to keep everything in the right orientation and location. A tack weld helps make this process much easier.
They allow a welder to move and turn objects to weld in different areas while maintaining the proper structure and location of all joints. These small welds can help reduce the need for permanent fixtures within a facility and help welders and companies save more money but reduce the need for fixtures.
How To Perform a Tack Weld?
If you are looking to perform a tack weld on your upcoming project you may highly want to observe an expert. If this is not an option for you, you can follow the simple directions. Basically, a tack weld is applied to a joint in the same manner as a final weld would be. The method in which you perform the final weld will determine how you perform your tack weld as well.
Remember, tack welds are small and often evenly spaced but they are just as important as the final weld so it is critical that you take time to get it right. Not doing a tack weld right the first time can throw off the entire orientation of the project and result in you needing to do more work and spend more time.
If you are performing a weld using the friction stir welding method, you can weld with the same process as the final weld, the same tools and same aluminum alloy materials.
If you are using an electron beam tack welding process you will apply tack welds to your materials using a lower setting than you would for the final weld. A lower setting will still give you an excellent weld but will make it easier to undo if needed.
Tack welds are important due to the fact that it will give you accurate and clean welds while minimizing fixtures afterwards, here are some basic tack welding steps to look out for:
Reducing The Risks of Tack Welding Defectives
While tack welds are small welds that are used to hold together pieces of a larger project, they are just as important as any other weld would be. If a welder does not take proper care when applying tack welds it can significantly increase the risk of anyone in the area and risk the outcome and quality of the final project.
To help reduce risk, all welders should ensure that if they make a tack weld it is of high quality and high importance. If a tack weld is not welded properly and the structure gets moved the weld could break and this could result in pieces of the structure falling apart and causing severe injury or even death to innocent bystanders. No project should ever be moved unless it is cleared by an inspector or thoroughly looked at by a second party.
Another risk of tack welding is reducing the overall quality of the structure and the welds. Each time a welder welds a piece of metal on a larger structure they are changing the overall shape, composition and structure of it. If a weld is not performed properly it can result in damage to the metal, which may go unnoticed.
For example, a weld defect could cause strikes, hard sports, cracks and even craters. These sensitive areas will then completely change the structure and quality of the material. If there are invisible cracks it can cause danger and unnecessary risk during the quenching and cooling process.
To help reduce the risk of tack weld defects it is critical that all welders understand the importance of tack welds. While tack welds are small, they serve a greater purpose. They should only be performed if necessary and if the welder is going to take their time and care. Rushing the tack welding process will only cause more damage in the long run.
Reducing the Risk of Distortion
Tack welds are used to hold joints and materials in place until the final welding process. To ensure that the pieces are aligned properly, tack welds need to be welded correctly and that comes with practice.
If you are trying to weld a long seam of a metal object it may appear quicker to just start at one end and weld to the other end. This should always be avoided.
If you are performing tack welds, the proper way to do it is to start in the middle and weld one spot. From there you can move the one direction and place another tack weld. Then go in the other direction and make another small tack weld. You should continue in alternating directions until you finish the job.
This helps reduce the risk of distortion and ensures that everything is aligned properly. When you are finished, or even half finished, the seam you should inspect for movement, joint gaps, and stress deformation. If you notice any signs of these things you may need to remove the tack welds and start over again.
Tack welds are a crucial aspect of the welding process. They serve an important purpose before the final welding can be completed. Regardless of how large or small the job may seem, tacks welds allow even the most expert welders to deliver a high-quality structure at the end of their job.
Every welder wants to deliver work that they can be proud to put their name on. Using tack welds correctly can help ensure that you do deliver excellent quality work that you stand behind one hundred percent.