Welding can be somewhat complicated, no thanks to the abundance of things that could go wrong during a welding job. One major fault you’ll possibly encounter pretty frequently is crater cracks. But what are craters in welding exactly, and how do you handle crater cracks?
A crater is a welding fault that occurs when an inadequate amount of molten metal is used to fill a cavity. It creates an opening for cracks, and when a crack occurs due to the presence of a crater, it’s usually referred to as a crater crack.
In this article, you’ll learn all a professional welder should know about craters and crater cracks. You’ll also learn some of the most common causes of this fault during a welding job and how to prevent it from happening while you work.
What Does a Crater Mean in Welding?
While a crater doesn’t sound like something that you should avoid, it’s one of the major faults that can occur during a welding job. Unless you’re satisfied with subpar works, you may want to take a deeper look at craters and what they mean.
A crater occurs in welding when an insufficient amount of molten metal is used to fill a cavity in a welding job, leading to a thin section. A crater looks like a hollow opening in the metal, due to the space caused by the inadequacy of the molten metal.
This defect usually forms when a welder stops welding prematurely. Since the welder doesn’t provide enough time for the molten metal to fill the cavity, it messes up the weld, creating craters.
Most craters happen at the end of a weld when the operator passes on the weld joint. Thus, craters almost always occur at the end of a weld.
A crater is a problematic part of the welding job, as it leaves a spot for the cracking of the weld. The opening at the end of the weld where the crater occurs can start a major crack, damaging the entire weld in no time.
What Is a Crater Crack in Welding?
If you already understood what a crater means, it’s quite easy to imagine what a crater crack means. Since a crater is an opening that’s very prone to a crack, the most logical conclusion is that crater cracks are cracks from a crater.
For a person with no previous knowledge of what a crater means, however, that will not be very helpful. A standalone definition will be more helpful, painting an accurate picture of what a crater crack means without having to rely on the definition of a crater.
With that said, a crater crack is any crack that occurs due to an opening created by the inadequacy of molten metal when filling a cavity in a welding job. It usually occurs when a crater is left unattended, and it’s one of the major types of cracks in welding.
When a welding job starts cooling, it begins to contract, starting from the ends. Throughout the process of cooling, the ends of the weld will be exposed to the highest residual stress, as the contract the most for obvious reasons.
Due to their exposure to this stress, they’re typically weaker than other parts of the weld. If you read the previous section, you should also know that most craters occur towards the end of the weld, a place where the metal is supposed to be at its weakest.
If your welding job has a crater to the end, the weakness caused by the disproportionate contraction will be made even worse. Eventually, the weld will be forced to crack, partly due to the residual stress from the constant contractions and mostly due to the crater.
Crater cracks don’t usually occur immediately after the welding job. Sometimes, it may not occur for months or even years after the weld. The only certain thing, however, is that the job won’t live its supposed lifespan with a crater defect.
The best way to avoid experiencing a crater crack is by preventing the craters from occurring in the first place. Preventing craters from occurring isn’t rocket science, but it isn’t the easiest thing you’ll be doing in your welding career.
In the next section, you’ll learn some of the best ways to prevent crater faults from occurring. Then, you’ll also learn how to repair a crater if it has already occurred to prevent unwanted faults in the long run.
How to Prevent Craters from Forming in Welding
Before hating yourself over a minor crack, it’s important to understand that mistakes are an important part of welding. While you try out new tools and equipment, you’ll make mistakes and experience cracks, and frankly, they’re no big deal.
That doesn’t mean you shouldn’t take proactive steps to prevent a crater from occurring. While there are many suggestions for preventing craters when welding, the best way yet is by reversing the main cause.
Always try to ensure that the weld puddle is filled before stopping the arc during a welding job. You’ll make a lot of mistakes at first, but with time, you’ll gradually learn to do it without messing it up.
If you noticed that the craters usually happen when you’re using a specific material for your welding job, you should consider changing those materials. Always choose base and filler materials that you’re comfortable with and you shouldn’t experience any crater cracks during the welding job.
How to Repair a Crater in Welding
Sometimes, all of your preventive tactics won’t work and you’ll be left with an annoying crater in your weld. You don’t have to make do with that, as there are many ways to repair a crater that you discovered after a weld.
In most cases, you’ll have to remove the weld material by grinding it until the crater is nonexistent. Then, you restart the job, ensuring you use enough molten metal to prevent the crater from reoccurring again.
While other alternative solutions may work, most of them are iffy. But instead of betting your weld on an iffy solution, It’s best to try one that’s almost guaranteed to work.