If you are interested in exploring the field of welding, good vs bad welding is one aspect that must be considered as a beginner.
Knowing which welding is best or bad can guide you when working later.
That said, understanding good and bad welding is fundamental for us as welders.
Especially if, in the future, you will be welding for large-scale metal fabrication products projects.
To help you understand the purpose and criteria of a good and bad welding process, I have prepared this article as a medium for us to learn together.
Check out the information below!
How to Distinguish Good vs Bad Welding
We must do special procedures to determine whether a weld is good or bad in its visual aspects and internal parts. For the visual element, we can see it directly, so it is easy to assess.
As for the internal aspects, a more detailed examination is needed using various assessment indicators.
To see good welds and bad welds from the visual aspect, we can use general assessments, such as the following:
- Size. Please pay attention to the size of the completed welding and whether it is following the desired connection.
- Aesthetics. The appearance of the welding results can indicate whether the welding procedure is suitable. Make sure the shape, consistency, and uniformity of your work.
- Defects. Look for defects in the weld, which could be undercuts or porosity. If the defect is significant, it can have a big impact on the appearance and performance of your product.
Weld Inspection Methods
In addition to using the visual assessment previously described, there are several tools that we can use to help check the state of the welding results, namely:
1. X-Ray Weld Inspection
Another name for X-Ray weld inspection is radiographic inspection, which welders widely use regularly because of its high accuracy and efficiency.
We can induce gamma rays on the weld and surrounding metal to check whether the work is up to standard and whether there are any defects.
2. Magnetic Particle Inspection
For the electric current to pass through the weld material, unique probes are installed on both sides of the inspection area.
The probe will be diverted when there is a discontinuity in the electric current, such as a crack.
Meanwhile, the leaking electric current will penetrate the surface, which produces points of attraction or magnetic poles.
In this way, we can see where there are irregularities.
3. Liquid Penetration
A bright liquid colorant is applied to the cooled weld surface and waited for it to soak into the material.
After that, we can see defects or irregularities in the weld because there is a change in color on the surface of the liquid. The liquid will darken at the problem location.
Characteristics of Good and Bad Welding
Based on the welding method we use, several criteria or characteristics will determine whether our welding results are good or bad.
Now, because you may use several welding methods, I have categorized the characteristics of each welding based on the technique. You can listen to them below.
1. Characteristics of Good Weld
What makes a weld good?
I believe one of the factors is using the proper method so that the results are more effective and optimal.
You already know we use three standard welding techniques as welders: MIG, stick, and TIG welding.
Well, to convince you of whether the welding process is correct or not, then pay attention to some of the characteristics of good welding below as a comparison:
In the MIG technique, the following characteristics are a reference to how good your welding results are, which include:
- All welds are uniform and straight
- The surface of the weld material is very smooth
- The size follows the predetermined conditions or according to the client’s request
- No defects, such as undercuts and holes
- Consistency in the width, height, and thickness of the weld.
- There are no craters or dips on the bead.
While the characteristics of good welding results on stick welding are:
- There is no splash on the surface of the weld
- The size follows the request or requirements that have been set.
- There are no defects at all.
- Consistency in width, thickness, and welding height
- Uniform shape and size
The characteristics of good TIG welding results include the following:
- The size meets the agreed requirements or conditions
- When the weld is in the cooling position, you can see the colorful and bright results
- No slag
- The size of the joint is the same as the weld
- No defects such as burn-through or cauliflowers.
2. Characteristics of Bad Welds
You can also determine if your welding results fall into the bad category by looking at some of the features of bad welds in each type of technique you might use.
Some characteristics of bad welding in MIG techniques include:
- Welding results that are not straight and less uniform
- The weld bead size is too big and fat or too small and thin.
- Visual defects are apparent, such as holes and cracks.
While poor welding results in stick welding include:
- Inconsistent height, width, and thickness
- You find defects in the welding results
- It is challenging to remove slag and spatter on the weld surface
- Weld beads that are too big and fat or too small and thin.
The characteristics of poor welding in TIG welding include:
- At the beginning and end of the welding, there are bumps
- There are defects
- It is difficult to clean the black or dull color on the weld result
- At the bottom of the joint, there is a burnt part
Preventing Bad Welding
To avoid bad welding, there are several considerations that we must make.
I suggest that you consider several aspects, such as welding techniques and information.
You can avoid the potential for making bad welds by using the proper methods and settings.
Some defects in welding results are generally caused by incorrect settings, techniques, and lack of knowledge. For example, spatter, voids, small holes, weld non-uniformity, porosity, weld overlap, etc.
The above problems can be reduced of course by improving your skills, knowledge, and techniques.
In addition, you can also look for professional mentors who already have a lot of experience.
By knowing important information about good vs bad welding above, you can avoid the risk of mistakes and losses.
Keep improving your skills with some of the previous suggestions. Remember to read books too!