Ever wondered why building a structure, vehicle, or machine made primarily of metals takes a long time to finish? For instance, it takes about four to six months to build a plane, and over ten times that to build an aircraft carrier. Thanks to advances in manufacturing technology, smaller vehicles such as cars and trucks can now be built in less than a day and that’s only because most of their components have already been prefabricated. So, it’s more like basic assembly than a construction.

One of the reasons is that a lot of factors must be taken into account when constructing these metal beasts, and there’s a different set for each type. Whether they are made up mostly of steel plates or bronze bars, their construction is at the mercy of these considerations. Safety, stability, and durability are just some of them. Manufacturing components and merging them together also take time. The assembly of machine parts is only made possible by a variety of techniques, the most common of which are fabrication and welding. Depending on the function and location of the machine parts, either method must be carried out.

Definition

Before we delve into the differences between welding and fabrication, it’s important that we first understand what they are and how they are carried out. Welding is a method of joining metal pieces together by melting their point of connection. Fabrication, on the other hand, is a method of joining metal pieces through cutting, bending, and assembly. Welding, however, must be distinguished from metal-joining techniques such as brazing and soldering, which involve melting a filler metal and not the base metal itself. As for fabrication, any metal-joining method that does not involve heating or melting the base metal belongs to this category.

Key Differences between Fabrication and Welding

Now that we know what welding and fabrication are, let’s try to differentiate them so we can identify situations in which they are ideal. It will also help us understand how they work and who we should turn to if we need either method for our projects.

They Require a Different Set of Tools

The fact that welding requires heating the base metal and fabrication doesn’t only means the tools they use are not the same. When you see a tradesperson prepare equipment like welding clamps, torches, power sources, and consumable electrodes, you can quickly tell that they will be performing welding. You may even find safety equipment and gear, such as auto-darkening welding helmets and respirators in the setup. When you see tools like cutting machines, including mechanical saws, laser cutters, and plasma torches, lathe, and bending machines, you know fabrication is about to happen.

Variety of Techniques Involved

In terms of goal, there’s a big, apparent difference between welding and fabrication. While both methods share the same purpose of constructing metal-based assemblies, welding’s main goal is to bond metal pieces together. By contrast, the goal in fabrication may vary as there are many different techniques classified under this category. For instance, your goal may simply be creating detailed cuts on a metal piece that would later be part of a machine, or perhaps you just need to bend metal plates to form a casing for delicate machine parts. Individually, these techniques are considered fabrication.

They Are Not the Same Profession

Unless you are a highly skilled and experienced metalworker, it’s hard to imagine you could perform both tasks excellently. Welding and fabrication are completely different disciplines, and so they require different skill sets, which can only be developed through many years of separate experience. If you need both welding and fabrication in your project, take note that you will have to hire two different groups of professionals—welders and fabricators.

Pros and Cons

Even though there are circumstances where either welding or fabrication is the ideal method to use, they still have a share of pros and cons that you can consider in your choice when you’re working with metals. For instance, when it comes to efficiency, welding is occasionally a better bet because you can do it onsite and instantly without the need to take the metal to a metalworking facility. It’s also the preferred option for large-scale construction applications.

Contrariwise, fabrication has many perks over welding, too. If you want quality work with guaranteed stability, you’d like the parts of your machine to be fabricated rather than welded together. Welded structures are likely to be less sturdy than fabricated ones because their parts don’t initially come in one piece. Also, let’s not forget that heat used in welding may trigger a chemical reaction on metals, which affect their properties on a molecular level, ultimately reducing their sturdiness.

Can Copper Alloys Be Welded or Fabricated

Metals like bronze and brass are among the most commonly welded and fabricated materials around. Assemblies with intricate compositions that are made mostly of these metals are proof of that. Their malleability and ductility allows them to melt and weld easily as well as be machined into accurate cuts and shapes.

This, however, depends on the type and quantity of metals alloyed to them to manipulate their properties. For instance, if you mix too much lead, the alloy becomes less workable, which makes it hard to bend without breaking. Understanding proper metalworking can help produce high-quality copper alloys that are ideal for welding and fabrication applications.

There’s no denying the suitability of copper alloys for welding and fabrication work. The question now is how can you be so sure that you are using the highest quality materials? That’s when reputable bronze and brass suppliers like Rotax Metals come in. Not only do they have their own certified foundry, but they also have an amazing selection of products. You’ll never have to go to multiple providers again.

Source:
https://howchimp.com/how-long-does-it-take-to-build-an-aircraft-carrier/

We’ve all been taught about Bronze Age being one of the most popular and longest periods in human history. This is the period where bronze production and use first became widespread across the globe. Even when the Iron Age finally set in, bronze remained an essential metal for a vast array of industry-specific and day-to-day applications. In fact, even today, bronze production is a thriving industry.

Bronze is an alloy commonly made of about 88% copper and 12% tin. This proportion can be adjusted to produce different types of bronze, each with distinct qualities that fit specific applications. Other metals, such as aluminum, manganese, nickel, and zinc, and non-metals or metalloids, such as arsenic, phosphorus, and silicon can also be added to improve bronze’s properties so as to make high-quality brass bars, tubes, and plates.

Why does bronze tarnish?

While metals are among the toughest materials on the planet, they do have a weakness. Some metals corrode when exposed to certain substances for a significant period, while others form a protective layer that prevents further deterioration. Bronze belongs to the second group, thanks to its copper component.

Copper is well-known for its natural ability to turn green over time. This green film, called patina, is the result of copper molecules reacting to the elements in the air or liquid they are exposed to. It takes years for copper to become fully cloaked with a green patina. It all starts with tarnishing, which doesn’t cause bronze to change color yet but it takes away its luster.

Stages of Bronze Patination

All metals that contain copper undergoes the same patination. They only differ in the rate of color transformation. The process is quite easy to understand, too. Natural patina formation is triggered by the oxygen present in the air or moisture, although other elements may have the same if not greater effect on copper.

As oxygen molecules land on the surface of copper, a reaction is triggered, causing the formation of copper dioxide. At this stage, patina is just in its tarnish form, nothing too vivid has taken place yet. Copper dioxide makes contact with a new batch of oxygen and reacts to form another layer of material called copper oxide. At this point, you’ll notice a significant change in the color of the surface of bronze. Different colors can be produced by exposing bronze to other chemicals, such as sulfur and carbon dioxide.

When two molecules of copper dioxide react with one molecule of carbon dioxide and one molecule of water, a type of patina called malachite is formed, which is characterized by a dark green or bluish color. Two molecules of carbon dioxide and one molecule of water reacting with three molecules of copper dioxide form azurite, which gives bronze a shade of blue or purple. To achieve a dark green or emerald shade, four molecules of copper oxide must react with one sulfate molecule and three water molecules.

How to Clean Tarnished Bronze

No matter how long it takes patina to form on the surface of bronze, it’s actually quite easy to remove. It’s even easier to polish bronze if it has just started tarnishing. If you have bronze tube, plate, and other items at home that you’d like to bring back to their elegant, shiny state, here are some simple tips on how to clean bronze that you should follow.

1. Wash the item with soap to remove excess dirt and grease from the surface of your bronze item. Rinse carefully and dry under the sun.
2. While drying your bronze item, prepare a lemon juice and baking soda solution. Two tablespoons of baking soda drizzled with a small amount of lemon juice should form a paste, which you will later apply on the surface of the item.
3. Once the bronze item is completely dry, start applying the solution on its surface. You can do this using your hand but make sure to wear gloves or by dabbing with a clean, dry cloth.
4. Allow the paste to stay on the surface of the bronze item for 20 to 30 minutes. Then rub gently with a clean cloth until it becomes shiny again.
5. You can do this process with other copper alloys, such as brass. However, some brass items have a gold-like coating for added luster, which may come off if you rub too hard.

How to Force Tarnish Bronze

Of course, if there’s a way to remove tarnish fast, there’s also a way to expedite the formation of patina on bronze. Patina, after all, isn’t always considered a blemish that needs to be polished off. Some people love the look of aging bronze furniture or fixtures. Here’s a quick guide.

1. Clean and dry the bronze item thoroughly to remove dirt and grease.
2. Heat the bronze item and apply an undercoat of bismuth nitrate. This will give the item an opaque white coat.
3. After applying the undercoat, start brushing on ferric nitrate, but make sure to keep the bronze item warm by periodically heating it.
4. When you’re done applying ferric nitrate, you should be able to see a little bit of change in the color of the bronze item. You can further increase this color change by applying cupric nitrate next.
5. Apply wax to protect the surface of the item and wait for your desired tarnish shade to emerge.

It pays to know a thing or two about removing and forcing tarnish on bronze. If you are into crafts, this can be a profitable skill. Then again, to make sure that your bronze items are of high quality, you need to consult with copper alloy experts like Rotax Metals. Not only do they give the best advice when it comes to choosing the perfect metal for every project, but they supply the highest quality products, too.

Sources:

https://www.worldcoppersmith.com/copper-patina-guide/