Welding is been an important part of today’s modern world and becoming the most used profession in the world. According to the US bureau of labor statistics, the USA is facing a massive shortage of welders. So, many new guys are into the welding profession, but struggle to achieve the perfect welds.
Making welds on your own isn’t a big deal, achieving quality and excellent welds is the job that should be done. There are some welding techniques that require proper skill and practice. However, we’ll discuss the attributes of quality welds and the difference between good weld vs bad weld.
Contents
Features of Perfect and Quality Welds
Every sector and person places high importance on having high-quality welds. We require strength and quality in every weld. These two are directly proportional since a weak weld would have a weaker strength and a strong weld would have a high quality and strength.
Apart from the welding process from which it’s created, good quality welds speak itself with a nice appearance, smooth bead, continuous welds, very less slag and spatter, strong and leakproof joint. The main point is that solid welding eliminates risks and expensive damage.
Welds are made using a variety of welding techniques, so we’ll talk about the most popular ones and what’s the reason for their good and poor welds.
TIG Welding
Tungsten inert gas welding is the most technical and complex welding procedure. Beginners will second me that it’s a dream of many to achieve perfect weld using the tig technique. However, with all its complexities, it’s the best for aluminum welding. As shown in the image, it produces the cleanest and most smooth welds without spatters. It’s used to weld copper, brass, carbon, stainless steel, and many others.
Reasons behind bad TIG welds
The common reasons behind the bad tig welds are the inappropriate size of filler metal, no cleaning before weld, improper amperage flow, and incorrect angle. These images clearly explain the whole scenario.
Signs of Good and Poor TIG Weld
- No slag
- Neat & clean welds
- Flawless welda
- Appealing
- Without any pattern
- Looks terrible
MIG Welding
Metal inert gas welding is the fast-growing and simple method that’s the first choice of many. One can achieve perfect welds without too much practice or skill. The process is so simple, welding gun uses the wire electrode to join two metals. Instead of tig, you don’t need filler wire because the wire electrode also acts as a filler material. Mig welding is widely used in home repairs, auto work, and DIY projects.
How to achieve good MIG weld?
Before diving into this process, you should be aware of wire feed rate, shielding gas, travel speed, and proper use of voltage according to the metal. If you’re mig welding aluminum, you should know about the usage of a spool gun. Keeping in mind these factors can lead to quality welds.
Reasons for poor MIG welds
Some of the most common reasons are very fast or low traveling speed, incorrect voltage selection, using the wrong mixture or shielding gas and improper use of wire feed rate can results in these welds as shown in images.
- Smooth
- Without any cracks and holes
- Uniformed
- Straight welds
- Too much spatter
- Weak joints
- Thin beads
Stick Welding
Stick welding is the most widely used welding method around the globe because it’s easy to use, the most economical method doesn’t include much complexity and can work on multiple metals like nickel, copper, alloy steel, stainless steel, and iron.
Good and Bad Stick Weld Bead
The stick bad welds occur due to improper use of current, voltage, and travel speed. With the high amperage, you can’t control the weld puddle that creates spatter whereas low amperage will stick the electrode while initiating the arc. Moreover, arc balancing is also important because a short arc keeps the electrode stick with base metal, and a longer arc creates the spatter.
Instead, a good weld looks appealing with a straight, uniform bead and less spatter. There won’t be any flaws, cracks, or holes in a high-quality stick weld. Rest can be seen in the image.
- Less spatter
- Straight
- Uniform
- Cracks and holes
Oxy-Acetylene Welding
It used to be the most popular welding technique, but since the development of more advanced techniques, only experienced welders and few industries still utilize it. In the process, acetylene and oxygen produce heat to weld base metal by adding filler metal.
Inaccurate torch adjustment, incorrect flame, travel speed, and improper weld surface cleaning can all have an impact on the weld bead produced by oxyacetylene. A good bead, on the other hand, is one that is consistent and free of flaws like holes or cracks.
- Smooth bead
- No cracks or holes
- Consistent
- Unstable bead
- Inconsistent
- Holes
What Impacts the Weld Quality in Good Weld Vs Bad Weld?
Every welding procedure has several variables that may influence the quality of the weld. The common points are voltage, amperage control, welding speed, and shielding gas. Anyway, we’ve discussed all this in detail.
Travel Speed
It should be controlled by a welder. Too slow travel speed puts a lot of heat on metal resulting in a wide bead and poor penetration. Slow speed can burn thin metals like aluminum. On the other side, fast travel speed creates narrow beads without any consistency and penetration. So, weld or travel should be according to the metal.
Voltage Selection
Keep in mind that voltage affects the height and width of beads. Low voltage affects the arc start, penetration, and control. There are high chances of spatter and ugly weld. On the opposite side, one has no control over arc, penetration, and weld pool with a high amount of voltage. So, follow the manufacturer’s instructions for each metal that is given on the welder.
Shielding Gas & Metal Cleaning
Use the correct shielding gas or a mixture of gases for every material welding. Incorrect gas flow rate according to metal can’t secure the weld pool from atmospheric impurities. Before welding, clean the metal surface with the grinder or brush to remove rust, oil, or paint to increase the life expectancy of the welded part.
Filler Rods
We all emphasize choosing the appropriate filler metal for the base metal while using welding operations like tig, mig, or stick. Additionally, the filler rod thickness should match the welding machine. This info would be interesting for you that a large filler rod can’t generate the required heat to melt its metal quickly into the weld pool. On the other side, a small rod will consume quickly, so you can’t manage the weld bead in a smooth way.
Frequently Asked Questions
Even though there are many points to measure weld quality and every one has its own criteria but all are agreed on these points:
- Weld finishing according to design.
- No crack, holes, or undercut.
- Appearance and strength of the weld.
You ought to be known with the fundamentals of the welding process before you begin. For a good and quality weld, learn the basics that are explained above such as heat control, weld speed, and filler metal selection.
Due to several technicalities, TIG welding is the most difficult and complicated type of welding, whereas stick welding is the simplest.
Conclusion
Welding is an in-demand skill with a lot of potential. There’s always to learn more and more in the welding profession. After giving a read to this article, you’ll be able to find the difference and reason between good weld vs bad weld.
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