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Brazing vs Welding vs Soldering Guide

Posted on October 8, 2011 by JeremyLeave a comment

Introduction

Joining two or more pieces of metal has pretty much been a part of all the metalworking we encounter in society. The reason for this activity is a necessary means in order to come up with the required size, shape, and especially strength in producing certain metalwork. There are many ways with which metals of any kind can be joined and the approaches are generally inclined towards choosing between brazing vs. welding. The methods used could vary according to the peculiar needs of any given task but the objective is basically the same for both and that is to produce a final work that conforms to the specified needs. Though both methods produce the fusion of two or more pieces of metals into one cohesive piece, the difference basically lies in the types of metals to be fused and the overall objective desired. It is then important to understand the two methods before any of which are used in any given task.

Welding

Like other methods used in joining metals, welding is generally used for purposes of fabricating metals. It is applicable in metal workings that require heavy duty fusion of metals. The strength derived from the use of this method if done properly produces a sturdy bonding as compared to brazing or soldering. The most popular type and widely used is known as arc welding. The process involves the use of electric current that passes through an electrode stick attached to the handle and acts as metal filler at the same time. There are various types of welding methods and it can be done in different environments like underwater, and even in space.

For a more intricate form of joining delicate metals, TIG welding is also one form being used and this is especially applicable in joining and/or fabricating thin metal sheets like stainless, copper, alloy or aluminium and others. The use of this method requires expertise because it is more difficult to learn as compared to the usual arc welding done in households and many repair shops. It is actually the welding approach used in creating space vehicles and this could very well give an idea how delicate this process is as compared to other forms of welding.

Brazing

Brazing is one form of metal joining that fuses two metals using a filler. The heat is just enough not to melt the base metals but strong enough to soften or liquefy the filler. Once the heat subsides, the filler that melted becomes glued to the base metal and essentially becomes a part of the two pieces of metals joined together. Many questions have been asked on which is actually better and provides a stronger bond when it comes to some forms of metals like aluminium so the distinction is made between brazing vs aluminium welding in many instances. The main difference actually lies in the size of work to be done on the material such that if the work requires joining aluminium pieces on large scale, then welding it is the more practical approach. But if the work requires smaller or thinner aluminium, then brazing is much better in most instances.

There is also the question poised on tig brazing vs welding and it is interesting to note that the difference is basically the same as in the usual brazing and welding methods. With TIG brazing, as in other works employing the same method, the base metals must not be melted and the only thing that needs to be heated thoroughly to the point of melting is the filler which is then guided to flow into the joint and make that desired joint. As usual, this method is applicable to smaller pieces of fabrication and not advisable to be performed on large metal works.

Gas Brazing

Gas Brazing is one of the new forms of brazing nowadays and one of the latest technologies to use natural gas in high pressure state. It is more economical and less dangerous as compared to acetylene and that is why it is becoming very popular nowadays. Another form of gas is used and that is hydrogen, and is quite effective as well as a favorite of many blacksmiths. Depending on the type of work, and as regards gas brazing vs Welding the former is the preferred type and this is especially in small fusing metal tasks like auto radiators, fabricating copper tubings, and others that require a perfect sealing of the gaps just like in case of air and gas tank fabrication.

Soldering

Soldering is used interchangeably with brazing. The former is actually more regularly used in referring to brazing works but the experts know that the two are not the same in many respects. With brazing, it can be done on thick metal casts and even large sheets of metals, and the purpose is basically to fill the gap in the material like a hole or anything that requires filling. It can be used to fill and later on create a hole to accommodate a nut or a screw to improvise. It can be used to repair and fabricate metals to fit a specific purpose and the end product is basically as strong, or possibly even stronger than the base metal itself if done by experts.

Soldering on the other hand involves basically the traditional joining of two metals. The filler is allowed to melt to fill the gap and with a careful stroking fashion from left to right or up and down, the gap will be filled creating a fusion of two metal sheets. It is done on thin materials and not advisable on thick ones because only the external part is actually joined in most instances. The strength of the joints fused by soldering is not as strong as compared to brazing and that is why the former is not advisable on thick metal casts that will require the strength to withstand pressure in some metal works. So to decide which is better in terms of metal fusion and fabrication and whether to prefer brazing vs welding vs soldering in any given task is up to the blacksmith. Only one thing is required in all three options, and that is the necessary expertise in using any of the three methods.

The Brazing Hearth Wiki: Brazing Process, Building a Hearth, Safety & Parts,

Posted on October 8, 2011 by JeremyLeave a comment

Brazing is the process of joining metals using a metallic filler material to flow across the joints to create an invisible, resilient bond between the base metals. A perfect model for nearly all metalwork projects done in schools and colleges, brazing is also used in the industry for:

a) Tool-making,

b) Manufacturing of bicycle frames,

c) Fasten hard metal tips, such as carbide, ceramics, and cement to tools like saw blades.

Brazing vs. Soldering and Welding

Similar to soldering and welding, brazing forms a strong joint that can withstand a broad range of temperature and different motions, such as jolting, shuddering, and twisting.

However, brazing, soldering and welding use different metals and work on different temperatures. Brazing can be done using brazing rods, pipes, flat metals, or other shapes provided that the metal pieces can be mounted against each other without huge spaces or cavities. Welding creates spot welds on easier, straightforward, and uncomplicated shapes, whereas brazing can manage more unfamiliar and not-so-common configurations.

Brazing has more advantages over soldering and spot welding. A brazed coupling is smooth and complete that creates a sealed, flawless, and waterproof joint, which can easily be coated so the joint melts and vanishes. Brazing is the only process that can connect and bond divergent types of metals with different melting points, such as steel, bronze, aluminum, copper, and wrought iron.

How to Build a Brazing Hearth

A brazing hearth normally comprises of three vermiculite blocks with a 200-mm by 230-mm plate and insulation blanket. Thermalite and vermiculite are considered the best material to use in building a brazing hearth.

However, these blocks are difficult to find; hence, a firebrick can be used as a substitute as they are readily available from brick suppliers and companies selling stoves and fireplaces. Furthermore, firebricks are difficult to find and easily crack due to heat, it is recommended to purchase brazing hearth bricks for spare.

A homemade brazing hearth should be robust enough to withstand the high brazing temperature. Building a brazing hearth starts with building a jig, a fixture that is used to hold the metal pieces in its position while being assembled. A homemade brazing hearth is normally made of firebricks inside a steel enclosure that is welded on an angle. The brazing hearth bricks are simply held in friction and clamped in place using an angle iron. The strips are then welded so that they will not slide out.

Some people also use the big stones from pizza ovens as a replacement for vermiculite blocks and firebricks. A large brazing hearth can be constructed by purchasing extra briquette.

A lot of people also prefer mobile brazing hearths that they can use outdoors. Mobile brazing hearths are usually made of steel angle and sheets with a hood that catches and extracts fumes. These types of brazing hearths are lightweight so that they can easily be transported. These mobile brazing hearths are not more than 18 inches deep, which can pass through a standard door.

The Brazing Process

The brazing process normally comprises five steps: cleaning the mating surfaces, fluxing the metal pieces, assembly of parts for brazing, brazing the assembly, and cleaning the brazed joint.

1. Cleaning the surfaces of the metal pieces:

Capillary action does not work properly on filthy surfaces; hence, the whole area where the metal pieces will be joined should be cleaned to avoid clumping of the melted braze mixture. If the surfaces are contaminated with oil, dirt, or grease, the brazing filler metals will not hold and an inconsistent joint will form.

2. Applying flux to the base metals:

It is highly recommended to wash the surfaces of the material before applying the melted flux. Flux is a chemical compound, usually in the form of liquid or paste, which removes the oxides and prevents more oxidation that occurs during brazing. Additionally, flux smoothens the surface of the metal pieces to facilitate uniform flow of braze throughout the joint.

3. Aligning and supporting metal parts:

Before heating and brazing the parts, they need to be aligned and supported. The best allowance between two metal pieces that will be brazed is usually 0.001 inch to 0.003 inch, generally not more than 0.005 inch. During assembly, it is necessary to ensure that the first metal piece is fully inserted to the other metal piece before brazing them together.

4. Brazing the metal pieces for assembly

The actual brazing process consists of two parts: heating the base metal pieces and applying the filler metal to the connection. Regardless of the heating apparatus utilized, make sure that both metals are extensively and equally heated. The heating equipment can be a brazing torch that uses acetylene or hydrogen that will help create a very high brazing temperature. The standard RF80 brazing torch usually gets hot between 800°F and 2000°F, but low enough not to melt the base metals.

The joint is completed by brazing a tube to a fixture or connector. After the brazing torch has heated the base metals, bring the brazing rod to the hot base metals until the braze melts and flows around the joint, penetrating the entire junction. The brazing rods melt at a lower temperature than the metal so it forms a molten liquid, which flows along the joint between the two metal parts. When the joint solidifies and cools completely, the junction becomes permanent as long as the brazing process is done correctly.

5. Cleaning the brazed joint

While flux was applied to the metal pieces before brazing them, it is necessary to remove the flux residues after performing the brazing process, by brushing or swabbing the flux using hot water. More stubborn flux residues can be removed using wire brush.

Some Products: –

Flame fast have developed brazing hearth DS320 where brazing and forging can take place in the one part in the combination unit sections. This unit is an improved version of the brazing hearth units DS430S and DS430D that have individual brazing and forging areas.

Brazing Hearth Safety

The brazing process itself and utilizing a brazing hearth are potentially dangerous. When reached a very high temperature, it can result to serious burns; hence, safety procedures should always be observed and never ignored. It is highly recommended to observe the following safety tips when working with brazing hearth:

Always face the brazing hearth when using it.
Remember to wear goggles to shield the eyes against hot splashes of flux, which could cause permanent damage to the eyes.
Wear leather aprons and gloves for protection against hot metals.
Use tongs to handle the heated material.
Allow the substance to cool on a block or steel plate before moving it to another place in the workshop. The steel plate will absorb the heat from the metal but not trying to cool it too quickly.
Turn the brazing torch on slowly and carefully but never turn the brazing torch around, which is highly dangerous.
Focus on the brazing process while heating the base metals, and place the brazing torch back to its place after using.

Keep in mind that to be successful in brazing or any kind of metalworking, safety should be considered a priority.

What Is Brazing Used For? Plus Supplies, Technique And Equipment Review

Posted on September 4, 2011 by JeremyLeave a comment

The process of solidifying two metals to one another is typically referred to as welding, save for those professionals who understand the difference between brazing and welding. For the most part, welding is the process of joining to metals which are melted together, through a variety of mediums, and are then filled with another material to form a solid and durable connection between the two metals. Welding is commonly used in joining materials like steel and iron and is used in a variety of settings, including underwater.

While the two techniques may seem similar, brazing is actually not the same metal-joining technique as welding. The process of brazing is different in that there is no melting of the original metals to be attached together. Instead a filler metal is melted, then placed at the joining point of the two metals to be attached to one another, where it is then cooled and solidifies the two metal materials together. Unlike welding, brazing can only be done under certain conditions as the hot filler metal needs a sufficient atmosphere to solidify the two pieces together.

While brazing vs welding will not be a topic of consideration, it is important to understand that there is a difference between the two techniques.

Brazing techniques

Like welding there are several brazing methods and brazing tools that can be used, each appropriate for different forms of metals to be joined and different uses of those metals. Each form of brazing requires various brazing supplies, based on the metals to be brazed, the atmosphere, and the type of brazing.

Furnace brazing

Through the process of furnace brazing metals are joined rather quickly and still very efficiently, for that reason it is one of the most popular forms of brazing for manufacturing industries that are producing numerous products. The equipment used for this form of brazing is easy to operate and can produce the filler metal at a particularly fast rate. However, as popular as this form of brazing is it is expensive and it requires the right atmospheric conditions to thoroughly fuse the metals together.

Torch brazing

Torch brazing is usually used on an individual basis in which there is only the need to produce one item of metal fused together by heat. This process is the most common across the world and is considered to be more affordable as it can be done manually, as well as with automatic machines if you so desire. Perhaps more so than any other form of brazing, those who torch braze manually must use extreme caution at all times. No form of brazing should be done however, without prior training.

Brazing Equipment

There are several pieces of equipment that are importantly incorporated into the brazing of metals. The following are just a few of those items:

Brazing rods

The brazing rod is the actual metal that is used as filler, the metal that melts when it is heated to connect the other two pieces of metal. Brazing rods can be made from a variety of metals and each is appropriate for the brazing of different materials. For example aluminum brazing rods are only appropriate for use in the fusion of certain metals.

Blazing rods vary in thickness based on the types of brazing metal that is used and based on the metals that are bonded together. Getting a brazing rod that is too thick or thin can have a dramatic effect on the drying and final process of brazing that you are doing.

Flux

The two metals that are joined must be purified prior to the cooling of the brazing metal, this cleaner is called flux. Some brazing rods come coated with flux, whereas other brazing rods have to have it added. Brazing flux should be cleaned off the finished product as it is known to cause corrosion.

Atmosphere

While an atmosphere is typically assumed there are various atmospheres that need to be used to solidify your brazing. Depending on the brazing metal that is used the atmosphere must be considered and altered. Some of the other atmospheres include Nitrogen, Argon, Hydrogen, and even vacuum chambers. Without the proper atmosphere the final brazed metals may not be able to firmly solidify.

Whether you are brazing steel or brazing cast iron it is important to find out the most suitable brazing rods for your base metals. Certain metals do not create a strong bond with other metals, for that reason it is critical that you understand the temperatures and strengths of the brazing rods with your original metals.

Brazing- Real World Applications

While there are smaller automotive and welding shops that integrate the use of brazing within their day to day activities brazing most commonly has a real world application in industrial settings. The following are just a few of the areas in which brazing is common practice:

Electronics manufacturers- Companies that produces televisions, radios, and even cameras commonly use brazing to fuse together metals and glass pieces, as well as metal and ceramics. Brazing is ideal in components that are small and hard to get to as welding in those areas would be nearly impossible.

Automotive industry- With a variety of metals under the hood of the car brazing is perfect for items on an engine block and even the successful implementation of pistons. Automotive manufacturers also need brazing tools which will help them produce thousands of the same car parts over and over.

Aeronautic industry- Several of the metals which are used in the engines of airplanes are joined through brazing because of the density ratios that must be maintained during flight.

While brazing and welding each have their ideal applications, requirements and conditions, brazing has proven to be superior to welding in several different applications. Understanding and learning the brazing of metals is a skill and a trade which will always be of use in our society. So long as the proper safety precautions are taken and there is proper training you can apply brazing techniques to just about anything.

Brazing Steel Metal, Tubing And Wire How-To Guide Plus Copper And Aluminium

Posted on September 4, 2011 by JeremyLeave a comment

Brazing is done when a filler material is heated to high temperatures and liquefied around two metals. It is then cooled within the appropriate atmospheric conditions. Once the filler has cooled within the appropriate atmosphere the two metals are fused together now as one. Brazing metal can be done with several types of metal including aluminum, stainless steel, copper and titanium.

How to Braze Steel

There is a process for brazing steel that should be followed in order to successful merge two pieces of metal. That process is as follows:

All measurements should be double checked and considerations should be made for metals that contract and expand under high heats. You must keep in mind that the filler must reach all points of the new joint in order for there to be a solid connection.
You must also determine the right brazing alloy with which to join your two metals together. For instance when you braze aluminum to steel you would need to use a brazing rod that is appropriate to both metals, like a vacuum chamber.
Purify the area that is to be the joint of the original metals with a degreaser. This will ensure that the brazing rod makes a solid connection with both the metals to be joined. After the area is cleaned it is important to use flux to prevent heat from causing oxidation.
Double check the positions in which you will be joining the metals together. You must double check always.
Braze the metals together at temperatures of 800°F for a sufficient hold.

The Right Atmosphere and Filler

Having the right atmosphere is critical to the final brazing product. While there are several atmospheres it is only appropriate to base your decision on the types of metals that are to be brazed.

When brazing stainless steel, you perhaps have the most options of fillers to use: Copper, Nickel, Aluminum, and even Gold. However, when stainless steel is brazed with copper the only atmospheres that can be used are Nitrogen and Argon. When Gold and Nickel are used to braze steel they must be done in a vacuum chamber or Hydrogen atmosphere. If Silver is used as a brazing material for steel it can also be done in our typical inhaled air. For those who are brazing steel form personal reasons Silver is the most commonly used filler.

When different metals are used as originals to be brazed together considerations must be made for the appropriate filler for both metals.

Brazing the Same or Different Kinds of Metals

Different kinds of metals maybe brazed to meet specific needs in welding or for the use in other endeavors. Some forms of steel brazing require special conditions in order to create the desired product and certain types of brazing supplies.

In brazing copper to stainless steel the filler material that is used is usually silver. This is to give the assurance that zinc and cadmium are not present which can affect the quality of the product.

Brazing copper to stainless steel will require the heating of both materials to its liquid form and placement within the filler material. The amount of heat needed is more than 840 °F to insure the fusion of both materials. Make sure that safety considerations are in place to prevent any unexpected incidents which can occur while in the process of brazing.

Welding aluminum to steel is not possible but brazing will fuse this two metals. Doing it may sound a little easy in theory but it is going to be very technical once put into practice. Silver brazing stainless steel and brazing steel tubing are done in the same method. The important thing is to clean and fluxed the area well before brazing is done. Do not overheat the stock this will stop the material in overflowing the spot. Boiling the material and brushing thoroughly will remove the flux.

Brazing steel rods and brazing steel wire are both used in different types of brazing. This material is available in different thickness to be able to reach areas that are deep like the edges or along the length or width of the material being brazed. The common application is maintenance and repairing activities like gas tanks that have leakage or even in the aviation and marine transports these can be used for cleaning purposes of petrol and diesel tanks.

Brazing can be done either manually for the creation of individual tools or to simply facilitate the fusion of two metals. For the purpose of mass production like creating masonry tools, developing holding tanks for oil refineries, and more, brazing steel will require the need for the right equipment that will be able to perform the specific tasks that are at hand.

Safety When Brazing Steel

Regardless of the type of materials used to braze steel, the brazing rods, or the atmospheres it is important to practice all safety measures. It is crucial that you only braze with proper eye protection and gloves. Clothes that are worn while brazing steel, or any metals, should be fitted as loose clothing can catch or become exposed to heat.

With brazing that is done in different atmospheres there are other safety conditions that must be met. Taking proper care to protect your respiratory system is important when using all atmospheres.

There are several online resources available to those who are interested in learning more about brazing steel and other metals. The internet gives you access to the best materials to braze with and the right brazing rods for every material. You will also find information on prices of brazing materials and most importantly the safety standards that should be met when brazing.

Brazing steel is perhaps one of the most common forms of brazing used in the industrial community. As steel is commonly associated with durability it is a common metal used in brazing. For those who are interested in brazing any metals together it is important to gain a thorough understanding of all aspects of the trade.

Brazing Brass Guide Plus Rods Review, BrassTo Stainless Steel, Copper Or Brass

Posted on August 22, 2011 by JeremyLeave a comment

Brazing brass is a thermal process of joining metals or alloys through capillary action. This process uses a filler metal which is melted at temperatures of more than 450 degrees Celsius to join base metals. During the heating of a filler metal a flux chemical has to be used so that it can facilitate the wetting of the metal rather than the formation of oxides. Brazing is normally conducted using hand torches although HF conduction, fixed burners, and resistance heating can also be used.

How to Braze Brass

The brazing of brass is mostly based on capillary action which is the flow of liquid through a narrow space or a tube and against the forces of gravity. When brazing brass to brass there are three metals which are involved, two of these are the metals which are to be joined, called the base metals. The third metal is a filler material which is used to join the base metals.

The first step in looking at how to braze brass involves the setting of a good fit between the base metals so that adequate space in left in a gap. This is a sensitive step which requires skill so that filler metal correctly distributes itself over a clearance. The tensile strength of the joined brass metals is influenced by the distribution of the filler metal; with a narrow clearance the resulting joint becomes stronger. This does not mean that the gap between the brass metals is the best with the least amount of clearance. Instead a balance should be achieved so that a clearance which is too narrow does not inhibit the flow of filler metal and one which is too wide does not reduces the forces of capillary action. In both cases the joint strength is reduced.

The next step in brazing brass is for all the metals to be checked for dust, oil, and grease. Effective joining of the filler to the base brass metals can only work if there is uninhibited contact with all surfaces. Joint formation will be affected by dirt particles on the brass base metals since they will prevent the filler metal from adhering to the surface.

Caution should be practised so that cleaning chemicals do not further contaminate the base metals since this will affect the capillary action. Immediately after cleaning the filler metal should be applied on the brass metals.

Fluxing must be included in the process of brazing brass. In this step a flux chemical is applied on the surfaces of the brass metals so as to seal them from air. This is necessary because during the heating of the base metals oxidation can occur as the heat comes into contact with oxygen. The choice of flux for this type of brazing should be compatible with the brass; it should also be applied immediately before brazing so that it does not dry out.

The base brass metals have to be positioned properly for heating. Supports can be added to give stability to the metals but they supports should be made of poor conductors of heat such as ceramic and stainless steel. Heating is then done broadly over the base metals. Interestingly it is not the filler metal which is heated rather it is the base metals which are exposed to a heat source. On bringing the filler material to contact with the base metals it heats, melts, spreads, and cools to form a joint. The trick brazing brass is to use a filler metal which melts at a lower temperature than the base metals. This way only the filler material melts while the base metals remain in solid form.

The last step in the brazing of brass metals involves the cleaning of the surfaces to remove excess flux and to get rid of oxides scales from the surfaces, if any.

Advantages of Joining brass by Brazing

Brazing is a preferred process of joining metals such as brass, because of the following advantages;

The metal is easy to work with and it is economical due to compatibility with other metals and alloys. For instance brazing brass to stainless steel or brazing brass to copper can be done with little or no difficulty even though the materials have different components and masses.
The joints which result from brazing brass are good conductors of heat, they are smooth, and are best suited for liquid and gas leakages.
Because of the high melting point of brass metals they are not damaged with heating, only the filler metals are affected in this process.

Notes to be taken on the Brazing of Brass

Caution should be taken not to use leaded brass since it melts before the brazing is started. Also the leaded brass has a tendency to crack during brazing thus leading to poor joint formation.
A reducing flame and a quality chemical flux should be used to prevent zinc oxide formation.

Rods for Brazing Brass

Amazon.com has a wide selection of bras brazing rods which can be purchased at the lowest prices.

Forney Industries 48492 Bare Low Fuming Brazing Rods

The Bernzomatic NS3 Brazing Rods come with the compatibility for high temperature fuel torches and oxygen torch kits. They are particularly effective for brazing brass to copper. The rods are recommended for use in small brazing applications involving brass metals especially for repair purposes. They are portable and are suited for induction heating.

Bernzomatic NS3 Brazing Rods

Other models of brazing rods can also be found at amazon.com. They include the Bernzomatic AL3 Brazing Rods, Import Er 70s 2 1/8 * 36 10lb Tig/ Brazing Rod, and Bernzomatic WB5 Brazing Rods. All these come with improved features for brazing as well as for cutting, soldering, and welding. With the use of these products there is a guarantee of higher quality from brazing brass.

Before any of these products are purchased buyers should be keen to find out if they meet the standard specifications for brazing equipment and if they are fitted for strength and durability. Otherwise the products pose health and safety risks.