Welding Preparation – Important Facts for Every Welder
Welding preparation is vital to produce strong, high-quality welds that look great and won’t crack. Removing contaminants and oxides is crucial for preparing the weld, whether you’re welding mild steel, stainless steel, aluminum, or another base metal. So, if you want great results from your welding, do the prep before you start to weld.
It’s tempting to skip the prep work before welding. After all, grinding metal or scrubbing with a steel brush is laborious, time-consuming, and dirty. And it seems like you’ve already worked up a sweat before striking an arc. But preparation is a step in the welding process you can’t afford to miss.
Why is welding preparation such a critical step in welding? What are the best ways to prepare metal for welding? These questions will be answered further in the article.
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Importance of Welding Preparation
Alexander Graham Bell—inventor of the telephone—is quoted as saying, “before anything else, preparation is the key to success.” This can also be said of tackling any welding job. Great welds start with thorough weld preparation. And it doesn’t matter if you have the best welding equipment, preparation before welding is most important.
Base metals quickly accumulate impurities on their surfaces. These could be as simple as dirt, grime, and grease. Or the metal surface could have signs of oxidation, rust, or be painted. Whatever the cases, these contaminants will impact the weld quality if they get into the weld pool.
Planning Your Welding Job Before Getting Started
Another aspect of weld preparation you can’t forget is planning. The best welders are masters at thinking backward. They envisage the finished result and then work back, meticulously planning each stage until they come to the first step.
Of course, a successful welder isn’t a backward thinker. They plan for success and never fail to prepare. Therefore, getting the proper safety equipment is another crucial step in welding preparation. So, before cleaning metals, get your welding safety equipment ready.
What you will need:
- Safety glasses
- protective visor for grinding
- heavy-duty gloves
- welding helmet
- welding jacket
- Good working boots
Surface Preparation in Welding
Surface preparation is one of the most crucial steps of all the welding processes. Preparing metal for welding has two steps—edge preparation and surface cleaning. First, the edges of the metal you weld must be shaped appropriately. Second, the joint surfaces must be free of contaminants.
The right type of surface preparation in welding depends on the metal. And every metal has different impurities to remove. Additionally, certain impurities have different melting points and conductivity levels. If these remain on the surface, the result will be an uneven arc, excessive spatter, discoloration, and weld defects.
For example, surface preparation for welding aluminum and it’s alloys involve removing the oxide layer. Also, aluminum welds are easily contaminated by moisture or grease.
Also, surface cleaning mill scale from steel differs from removing paint or rust. And the last thing you want is to use the wrong technique and drive impurities into the metal. Additionally, excess surface material on stainless steel can cause cracking when the weld cools.
And not to be forgotten is the need to ensure filler metals are perfectly clean. For example, cleaning filler metals is essential when arc welding stainless steel or aluminum.
Tools necessary for surface preparation to clean metal before welding
- Steel wire brush
- Knurled brush wheels
- Sandpapers in various grades
- Acidic (acetone) or alkaline (soapy) solutions for preparing aluminum surfaces
Before Welding there are 4 steps to TakeBefore welding pieces of metal together, experienced welders always prepare their equipment, plan the welding project, and take appropriate safety measures. Besides producing beautiful welds, the appropriate preparation before welding can minimize risks and safety hazards.
1. Plan the Welding Process
The first thing is to plan each stage of the welding process methodically. This step will help you decide on the best method of welding to use, what consumables you’ll require and other necessary materials. For novice welders, this stage is critical to avoid any hindrance during the welding process.
2. Inspect Surfaces and Metal Edges before Welding the Metals
A solid weld depends on surfaces being 100 percent free from contaminants and smooth edges that are ground to the proper angle. So, it’s time to put on safety goggles, gloves and the clear visor and grind the base materials to prepare them for welding.
After surface preparation and grinding the edges, thoroughly inspect all parts. The slightest scratch, speck of paint or rust, or rough edge could negatively impact the weld quality.
3. Organize Tools and Materials you Need for the Welding Job
Before switching on the welder, look around to ensure all tools are in their proper position. If possible, put the pieces of metal to be welded on the workbench as you plan to weld them. If that’s not possible, have your sketch visible and put individual pieces in order of welding.
Taking your time at this stage before welding can save you a significant amount of time later. It is also helpful to write out a list of the steps in the welding process and the order you will do them—something like a cooking recipe.
4. Take Appropriate Safety Precautions When Welding
Safety is not an option when welding. Therefore, before you pick up the welding hand piece and start the arc, you must have all the safety gear in place. You will require the appropriate personal protective equipment (PPE) and to always wear it.
It’s vital to consider other safety hazards when welding. For example, ensure the workshop is well ventilated to avoid exposure to harmful fumes and gasses. Remove all flammable materials and liquids from the welding zone. And inspect all welding current and current return cables thoroughly to prevent electrocution.
What Is Edge Preparation in Welding?
Edge preparation in welding involves beveling or grooving the metal to produce a strong weld. Preparing edges ensures excellent joint penetration. It is necessary when using groove or butt joints to create a bridge between the metal parts. Typically, the metal is removed from the edges to create a bevel angle or a V-shape.
What Is the Importance of Edge Preparation?
Edge preparation before welding metal is vital for achieving strength in a finished weld. Because the weld replaces the removed metal, the resulting weld is stronger and more robust than welding flat surfaces together. Although edging metal for welding won’t prevent every defect, it will increase weld quality in every case.
Especially for thicker materials, making a bevel on the plate edges allows for complete joint penetration. The electrode can then reach the root of the joint. The type of edge required—a V-shape, J-shape, or U-shape groove—depends on the metal plate thickness
Welding Preparation in Conclusion
Welding preparation is just as vital for producing strong welds as mastering welding techniques. The two essential aspects of preparing metal for welding are surface preparation and edge preparation.
Cleaning surfaces ready for welding must remove all impurities from the base material, reducing the risk of cracking and discoloration. Additionally, choosing the correct edge for welding strengthens the weld and reduces the likelihood of defects. The result of a beautiful looking weld will make all the effort of the preparation work very much worth it!
Leo Buckingham has a lifetime of welding experience. Working in Agriculture I can remember learning how to weld. It became a passion, first learning to stick weld and then progressing to MIG welding. Over the years I have learned a lot and wish to share this with others, and that is why I created Welders Galore.