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.
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 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 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 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.