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28 Detailed Questions (You Should Know) Answers About Brazing

  • By: Monica Shulz

Acknowledging the limitations, advantages, and strengths can help you know if it is the right technique for your applications. We, humans, have been brazing materials since the time of the Pharaohs.

Many years have passed but we often find brazed materials in various areas of human life. It is imperative to say that brazing has an important role in our industrialized community.

We use brazing for many applications such as kitchen cutlery, jewelry, automotive engines, bathroom faucets, HVAC systems, jet engines, high-temperature metalworking, ceramics, and much more.

However, you need to learn all there is about brazing, be it its end-use applications, adhesive bonding, or mechanical joining.

If you are an amateur hobbyist and looking for some answers, keep moving forward:

What Is TIG Brazing?

Making use of silicon bronze during TIG welding is technically termed TIG brazing. During welding, metal joints are created by applying concentrated heat. This phenomenon melts the metals and fuses them together.

As with TIG brazing, the base metal is at a higher temperature than that of filler metal. The filler metal is first melted and then directed in between the two metals to create a strong joint. As opposed to TIG welding, we take utmost care of cleanliness in TIG brazing. We apply less amount of heat and the contaminants are less likely to burn out during the process.

6 Filler Metals Used In The Capillary Action:

  • Nickel alloy
  • Silver
  • Gold-silver
  • Brass
  • Copper-silver
  • Aluminum silicon

Can You Use A Tig Rod For Brazing?

Yes you can use TIG rods can be used for brazing. TIG Brazing is another technique to join metals and is quite similar to welding. There is a huge variety of welding rods to braze two metals together. While some are ideal, others lack the element of cleanliness. Even though many welders prefer using brazing rods, TIG rods serve the same purpose.

2  TIG Rods That We Can Use For Tig Brazing:

  • Consumable electrodes
  • Non-consumable electrodes

However, experts say that one should only use TIG rod as a less-efficient substitute as welding and brazing are two separate techniques.

Why Are Bike Frames Brazed Instead Of Welded?

The reason why people braze the frames on their bikes instead of welding, because its much cheaper. Numerous custom bike frame builders prefer the brazing technique over the welding. Moreover, brazed frames are finished, cleaned, and neat-looking.

Coming more to the point, brazing has more scope with lugs as both are considered an expression of artistry and skills. Brazing and frame lugs go together well because the technique relies on the simple gap between two metals.

The aim is to fill the gap between the lug and tube without leaving excess material or voids. However, the expert has to move around the torch across the lug carefully to create a neat fillet.

Is Brazing As Strong As Tig Welding?

Welded joints are stronger than the base materials because metals are being fused together.
Welding creates joints by melting metals and fusing them together. However, we use a base material during the fusion process as the temperatures of the concentrated heat point must exceed the melting point of the filler material and metal.

On the other hand, brazing creates a metallurgical bond between the two surfaces and the filler metal. As temperatures are quite low in brazing, most physical properties of the filler material go unaffected. Therefore, brazing minimizes stresses, warps, and distortion.

Can Your Mig Weld Over Brazing?

No, you can’t MIG weld over brazing unless you start from scratch by removing the brazed filler material. Brazing filter metals such as nickel alloy have low melting points. Therefore, they will simply crack if you use a high-temperature MIG welding rod.

4 Reasons Why You Can’t Mig Weld Over A Brazed Filler Material:

  • It produces a weak weld
  • Weld pools contaminate
  • The base metal has a low melting point
  • Brazed filter metals have low melting points

Is Brazing Permanent?

Yes, brazing is permanent. It is designed to make a strong joint between two base metals with the help of filler metal. Unlike screws, bolts, nuts, and other mechanically fastened parts, you can’t take apart two brazed materials.

We choose either brazing or welding when it comes to creating strong metal joints. While welding joints are created by adding a filler metal, fusing and melting two base metals, brazing includes melting the filler metal and creating a strong yet permanent joint between two base metals. Technically, brazed materials form an assembly that stays permanent. However, one must do it properly and permanently to achieve optimal yet end-use conditions.

 3 Reasons To Braze For Permanent Joints:

  • Brazing is achievable in large surface areas
  • It is an economical yet effective technique in complex assemblies
  • It is effective in creating permanent joints between dissimilar metals

Is It Better To Braze Or Weld Cast Iron?

Brazing is the best approach to repair cast iron, especially if you need to build it again and achieve the right tolerance. The disadvantage of welding cast iron is you have to heat it before welding it. So, you can’t weld iron cast if it is cold.

Cast iron is a man-made malleable alloy made from carbon, silicon, and iron. A small portion of graphite or carbon exists as a free element.

You do not have to melt the base metal when brazing cast iron since the brazing rod has a built-in flux.

You Can Braze Cast Iron Under The Following Conditions:

  • The brazing rod must take a temperature above 1400 degrees to penetrate through the metal
  • For maximum shear and tensile strength, clearance of the brazing rod should be around 0.003

Can You Braze With A Bernzomatic Torch?

Yes, you can braze with a BernzOmatic Propane torch. The precise yet high-intensity flame from the torch provides sufficient heat output for brazing two metals permanently. Moreover, you can modify the flame sizes for various applications by using the control knob.

Best Way To Braze Using A Bernzomatic Torch:

  • Take the emery cloth or a wire brush to scuff the metal’s surface and clean it using a degreaser
  • For an overlapped joint, position the metal accordingly
  • You can use clamps to secure the brazing point
  • Heat the meeting point or the joint of two metals until it glows
  • Use BernzOmatic torch while applying heat to the joint
  • Use a wire brush to scrape off any kind of residue or oxidized debris

What Is Stronger Brazing Or Silver Solder?

Brazing is stronger as compared to soldering it has a lower processing temperature. This accounts for lower strength in a joint as compared to a brazed point. In fact, the shear and tensile strength of a brazed joint exceed that of silver solder joints by an element of 5.

3 Disadvantages Of Soldering Over Brazing:

  • Soldering can’t joint large surface joints
  • The produced joints are not designed for high-temperature application
  • Joints are of lower strength

Can You Braze Aluminum To Steel?

Yes, you can braze aluminum to steel but it requires a fast-heating ramp, rapid processing, and a short time when it comes to brazing temperature. Usually, we use induction brazing to join aluminum to steel.

Other Techniques To Joint Aluminum To Steel:

  • Friction welding
  • Arc welding

 

Is Braze Welding Strong?

Yes, a brazed joint is stronger than a welded joint. As the base metals do not melt in the process, we use low temperatures than welding to create strong joints. Only a filler metal is melted due to which the base metals get to retain their physical properties.

Whether you go for thick-section joints or thin joints, the base metals will have the characteristic to bond better from the filler material.

Moreover, the lower temperature ensures that the base metals are not warped or distorted. This does not only save your cost but also prevents the metals from bending.

4 Factors Of Metal Joining Process:

  • Base metals
  • Joint requirements
  • Assembly size
  • Base metal’s thickness

 

What Is Brazing Used For?

  • Light fixtures
  • Musical instruments
  • Installation of air condition systems, HVAC, and refrigeration
  • Industrial heating and cooling exchangers
  • Solar panels
  • Towel warmers
  • Radiators
  • Metal fittings of the chandeliers
  • Hard metalworking
  • Diamond tools
  • Tubular applications
  • Electromechanical systems
  • Silverware
  • Silver jewelry
  • Automotive and jet engines
  • Calibration instruments
  • Glasses

Brazing is a commercially accepted metal-joining technique to join two dissimilar metals. The technique is used in various industries due to its unique integrity and flexibility. The characteristics of brazing make it ideal for various critical and non-critical applications. In fact, it is one of the most widely used techniques to create strong bonds between different metals.

With its use in a variety of products, we can solve several technical issues and also manage the harsh production processes.

 

What Is Brass Brazing Used For?

Brass brazing is commonly used for making strong joints among iron, copper, and steel. In this brazing technique, brass alloys are used to carry out the Oxy-Fuel Gas Braze-welding process. Experts suggest using liquid flux through the torch flame to create strong and clean joints through brass brazing.

Brass brazing is as cheap and effective as welding. The great physical characteristics of cast iron, hard carbide, and carbon steel tools are the existing proof that brass brazing is commonly used in various industries.

4 Things Brass brazing Can be Used For:

  • Marine repair
  • Metal processing
  • Diamond tools
  • Bicycle frame

What Is The Working Principle Of Brazing?

  • Manual torch brazing
  • Torch brazing
  • Vacuum brazing
  • Silver brazing
  • Induction brazing
  • Dip brazing

In the brazing technique, the base metal has a high temperature as compared to the filler metal, that a low temperature. The filler metal is then heated. As a result of heating, the metal starts to melt and flows evenly.

The liquid filler metal then flows into the gap between two base metals to form a workpiece.

Simultaneously, the filler metal is protected by liquid flux to let it flow evenly. When the gap fills, the filler metal starts to flow on the base metals and wets then. The workpiece is cooled to inspect if the joint is clear, smooth, and strong.

Can You Chrome Over Brazing?

No, you can’t chrome plating on brazing unless you redo the joint. The same answer goes for brazing over a chrome-plated metal. The joint will not hold due to excessive oxidization on the surface of the metal. To braze chrome over the metal, you have to remove the braze plating in addition to grease, old paint, oil, rust, decals, and corrosion.

In short, you have to scrape off every element to adhere to the brazed metal over the base metal.

Can You Use Welding Rods For Blazing?

Yes, you can use welding rods for blazing. Even though welding and brazing are two different metal-joining techniques. A brazing rod is specifically used for welding. However, a traditional welding rod can bear the process of brazing due to low temperatures.

You would have to alter your technique a bit if you want to try brazing with a welding rod. But you can’t get a clear joint as only the brazing rod has the capability to heat the filler metal without coming in direct contact with it.

Best Welding Rods Are For Brazing:

  • Aluminum
  • Copper, bronze, and brass
  • Copper, nickel, and steel
  • Malleable iron galvanized or cast iron

Can MAPP Gas Be Used For Brazing?

Yes, genuine MAPP gas can be used for brazing, welding, and even soldering. However, it has to be used in combination with oxygen to provide sufficient heating. As compared to acetylene, it has a high-temperature flame. Moreover, it does not require a special container filler or dilution during transportation.

But the hydrogen concentration in the flame of MAPP gas is higher than acetylene. Therefore, it is not appropriate for high-scale welding or brazing application. The hydrogen infuses into the molten alloys and makes the joint a little brittle. But when it comes to small-scale brazing projects, MAPP gas is just the right product.

2 Advantages Of Using MAPP Gas:

  • Higher combustion temperature
  • Colorless

Can Soldering Flux Be Used For Brazing?

No, you can not use soldering flux for brazing. Only white/silver brazing fluxes are used for this process. Flux plays an integral role in all air brazing applications. If you apply it unprofessionally or use the wrong flux, it can ruin the quality of the brazed joint.

Special fluxes are available for brazing aluminum bronze, stainless steel, carbine, and tungsten. To reduce red staining and to achieve clear and strong joints, hobbyists use commercial flux-coated roads for induction brazing.

Properties Of White Flux, Used Specifically For Brazing:

  • Organic fluoride flux
  • Low temperature
  • Suitable for most non-ferrous and ferrous metals
  • Outstanding adherence
  • Enhances active lift during brazed temperatures
  • Great flow and fluidity

Can We Do Brazing For Mild Steel?

Yes, we can braze mild steel or cast iron because it gives strong joints as compared to welding. The purpose of brazing is to join dissimilar metals, mostly alloys. The metals which can’t be joined through welding are joined using the brazing technique.

When joining mild steel, you don’t need high temperatures. Therefore, brazing with a propane torch will do fine. Silver solder or the filler metal in the brazing technique flows better. Therefore, you will end up achieving a strong fillet covering all the internal corners.

The Metals That You Can’t Braze:

  • Gold
  • Silver

Can You Tig Weld With A Brazing Rod?

No, you can’t use a brazing rod to TIG weld. However, you can use the TIG welder to perform both metal-joining techniques, brazing, and welding. If you use a TIG welder to braze, it is called TIG brazing.

3 Advantages Of Tig Brazing:

  • Suitable for conductive metals
  • Precise brazing job
  • High-quality joints

Can You Use A Brazing Rod On Aluminum?

Yes, you can use a brazing rod on aluminum to repair broken ears, rivets, holes, leaks, and threads. In addition, you can also use it on cast iron and cast aluminum to fabricate easily and promptly. If you want a working temperature of 700 to 750 degrees, you can always use the BernzOmatic AL3 Brazing rod.

Apart from needing a brazing rod to join aluminum, you require flux in the form of dry powder. Mix it with water and apply while brazing to achieve smooth joints.

You Can Use The Brazing Rod On The Following:

  • Aluminum boats
  • Fuel tanks
  • Wheels
  • Aluminum heads etc.

Can I Braze Aluminum With A Propane Torch?

Yes, you can braze aluminum with a propane torch. In fact, a propane torch with a pointed tip is better than using a brazing rod to join braze aluminum.

4 Steps To Braze Aluminum:

  • Get the right propane torch to braze aluminum
  • No need to look for the working temperature as the propane torch burns enough to melt the filler metal
  • Clean your joint with a wire brush
  • Apply the flame from the propane torch to the joint until all the filler material has dissolved evenly

Can You Braze Over Solder?

Yes, you can braze over soft solder as long as you heat the metal fitting, wipe off as much solder as you can, and rag at the end for a clean brazed joint.

How Thick Of Aluminum Can You Braze?

You can braze easily if both the sections are 0.5 in. or greater in thickness. However, brazing works well if you want to join thin sections. If you wish to use a propane torch, you can braze 1/8” gauge aluminum. But make sure not to heat the rod with the propane torch.

The lower temperature and the broad coverage of heat help us create joints without distortions.

Can You Solder Steel Tubing?

Silver solder is ideal for brazing all types of steel. However, you have to use the solder with 56% silver in order to solder steel tubing. You can either use an oxyacetylene torch for quick joints or use acetylene, MAPP gas, or propane torch if it is not available.

11 Steps To Solder Steel Tubing:

  • Clean the steel tubing before the silver soldering process
  • You can use a wire wheel, a Dremel, or any such tool to clean the steel tubing
  • Heat the base metal with your propane torch to increase the temperature of the working area
  • Watch for the color change of the heated metal before adding flux
  • Apply flux around the steel tubing’s circumference while moving the torch with a flame
  • Make sure that you do not overheat the base metal
  • When the steel turns red, add the silver solder rod
  • Use your torch to move the melted silver solder around the tube’s circumference
  • Make sure that you fill the gap completely
  • Use warm water or a wire brush to remove residues of flux
  • Lastly, use the wire wheel to polish and finish the steel tubing repair

Can You Paint Over Brazing?

Yes, you can paint over brazing. However, you have to make sure that there’s no slag left. Otherwise, the painted fixture will look unclean.

Can You Powder Coat Over Brazing?

Yes, you can powder coat over brazed joints. Many bike owners are familiar with the process. However, the brazed joints with powder coating need special attention.

Brazing the metal leaves residues of flux, which can be a haven for contaminants. Therefore, the residual flux should be properly removed to ensure that the powder coat is all over the brazed joint.

You can remove these contaminants and the residual flux through a pickling solution or by sanding, grinding, and blasting.

How Much Pressure Can Brazing Hold?

The typical pressure that brazing can hold ranges from 1.3 to 0.13 pascals. However, the strength of a brazed joint depends on several factors. The bulk tensile strength of a silver brazed joint is between 40,000 to 70,000 psi.

4 Factors Brazing Strength Depends On:

  • Composition of the base metal
  • Joint quality
  • Service temperature
  • Clearance or gap between the parts

 

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