How to Braze
Posted on October 12th, 2009 by Marck
Loading ...
Joining two pieces of metal together is a very important skill learned in craftsmanship, metalworking, and industrial applications. A popular technique used by many craftspeople and metalworkers is brazing, where a strong, sturdy joint is built between two pieces of metal. If you need to braze metals for small handicrafts, here are the tools and steps you need.
What Is Brazing?
Like welding, brazing is a way of joining two pieces of metal together with the application of heat and another alloy. The joint is created by passing soft, molten metal through the gap between two stronger metals through capillarity. The combination of rapid cooling and the chemical bonds that take place between the metals creates a very strong joint that is very useful for many handicrafts, repairs, and other objects made from metal.
There are two kinds of joints that are used in brazing:
- Butt joint. The butt joint is a brazing joint made between two metals positioned edge to edge. The brazing alloy is applied directly to the edges of the metals, creating a seamless surface across the two metals when done correctly.
- Lap joint. The lap joint is a brazing joint where one piece of metal overlaps the other. The brazing alloy is applied in between the sandwich of metals, creating a very strong bond useful for applications and uses that require strength.
Tools
For many industries, acetylene torches and other high-end tools are used for brazing as well as welding. Small, hand-held brazing torches are particularly useful for people who work in cottage industries or want to use brazing as a repair method. Most of these brazing torches are powered by oxygen and acetylene tanks. Brazing rods are also available from hardware stores.
Some of the most common brazing alloys (also called filler materials) include the following:
- Copper alloys (may be alloyed with phosphorous or zinc, or used on its own)
- Aluminum-silicon
- Nickel
- Silver
Tips
To braze metals together, follow these tips:
- Always use safety equipment to avoid sustaining serious injuries.
- Brazing bonds only work if the metal surfaces are as clean as possible. Dust and debris can compromise the metallic structure formed between two brazed metals.
- Set the torch to the correct brazing temperature recommended for the alloys.
- Use the brazing rods to guide the heated brazing alloy along the gap or seam of the metals. One way to make sure that the alloy is evenly distributed and forms a cohesive, durable bond is to distribute and move the alloys in small, circular motions.
- Finish off the brazing process while allowing the metal to cool rapidly. Watch out for cracks and fractures, however, that could develop from the brazing process.
Metalworking can be quite easy if you have the right tools and techniques to do it. With these steps, you can braze metals easily and efficiently.
Ask a question
Comments