We utilize MAPP gas with a shield, which works well up to 7/8 copper tube only, and the braze joint must be kept away from any huge bulk of metal because heat can be pulled away almost as quickly as it is applied. If there is a breeze, it might be quite difficult to work outside; therefore, a wind break should be employed.
Is MAPP gas suitable for brazing?
Also, compared to a smaller, hotter flame, it produces more copper-oxide corrosion. As a result, Mapp gas-air brazing of heat-pump reversing valves, filter-driers, and compressors is not recommended.
You’ll use a torch for brazing just as for soldering.
Because brazing requires higher temperatures than soldering, you’ll want to use an oxygen-acetylene torch, which gets hotter than a MAPP gas or propane torch, though a turbo torch should do for most small-to-medium tasks (thinner copper pipe). It’s also worth noting that MAPP gas is hotter than propane.
Brazing rods resemble straightened metal coat hangers, and they, like solder, get stronger as the proportion of silver in them rises. The flame melts the braze to bind two metals together. Brazing rods comprised of a copper-phosphorous mixture are commonly used to link copper wires. This type of brazing rod melts at 1,190 C when it contains 6% silver.
You’ll need to heat your lines to the point where they’re practically flaming red while brazing. You must maintain your torch moving at all times while doing this, or you will burn a hole right through the copper tube. You’ll undoubtedly do this several times as you learn to braze.
Also, don’t be a slacker. People will tell you that when soldering, you must thoroughly clean the copper lines, however during brazing, this is not necessary. Listen. In any case, you’ll need to clean your lines. True, any contaminants will be burnt away because to the higher temperatures used in brazing. However, you don’t want carbon leftovers to contaminate your HVAC system. Steel wool, for example, can be used to clean your lines. Once you’ve cleaned the piping, make sure to blow it out.
Because of the high temperatures involved in brazing, your copper lines will oxidize once you’ve finished torching them. In other words, anywhere they are exposed to air, or more accurately, oxygen in the air, little flakes of burned material and soot will accumulate on them. This puts particulates into your cooling or heating system, which should be avoided at all costs.
Is it possible to braze with a Bernzomatic torch?
Use the appropriate brazing rod material for the metal you’re working with. The brazing rod should be melted by the heat of the metals being connected, rather than by coming into direct contact with the torch flame. Make use of a torch with a high-intensity flame.
Is it possible to braze with a gas torch?
Can I use a propane torch to weld aluminum? Yes, you can use a propane torch and aluminum brazing rods to weld aluminum if it’s for non-structural metals that aren’t weighted, strained, or important sections.
Propane torches do not typically reach high enough temperatures to accomplish successful aluminum welding.
Propane can be used to braze an aluminum alloy with smaller dimensions or for non-critical patches or repairs, but it is not advised for aluminum welding.
For aluminum welds, any welding procedure that uses a flux, such as stick welding or flux-cored arc welding, is ineffective. These approaches produce welds that are too porous for a proper weld.
The amount of BTUs a gas flame can concentrate in a concentrated work area is more important than the temperature of the flame.
Despite the fact that propane flames can reach temperatures twice as high as aluminum’s melting point, aluminum’s characteristics make it highly conductive and radiant in heat.
Although some welders believe that repair rods are adequate, their melting points are lower than the melting points of aluminum, making a proper weld unlikely. This is especially important for key things that are under a lot of weight or pressure.
Shielding the weld puddle from impurities is one of the most important aspects of aluminum welds, and shielding gas is essential for this.
There’s a reason why experienced welders invest in expensive aluminum-specific technology. Why would they spend the money if welding aluminum was as simple as some claim?
When brazing copper, do you need to use flux?
Fluxing is an important part of the brazing process, as we’ve already stated. Although this is typically true, there are a few exceptions. Using a brazing filler metal particularly prepared for the job, such as Handy & Harman’s Sil-Fos or Fos-Flo 7, you can connect copper to copper without flux. The phosphorus in these alloys serves as a fluxing agent on copper, so if you’re brazing the assembly in a controlled environment, you may frequently skip the fluxing step.
A controlled atmosphere is a gaseous mixture contained in a confined environment, most commonly a brazing furnace. The atmosphere (such as hydrogen, nitrogen, or dissociated ammonia) entirely surrounds the assembly, preventing oxidation by excluding oxygen. However, you may discover that a small amount of flux helps the wetting action of the brazing filler metal even in a controlled atmosphere brazing.
To braze copper, what temperature is required?
In practice, most soldering for copper systems takes place at temperatures ranging from 350F to 600F, while most brazing takes place at temperatures ranging from 1100F to 1500F.
Is it possible to braze without using oxygen?
By far the most used method of automated brazing is torch brazing. It’s best for small batch sizes or specialized processes, and it accounts for the majority of brazing in several nations. Manual, machine, and automatic torch brazing are the three main types of torch brazing in use.
Manual torch brazing is a method of applying heat to a joint by placing a gas flame on or near the joint to be brazed. Depending on whether the operation is fully manual or has some level of automation, the torch can be held in either a hand or a fixed position. Manual brazing is most typically employed on small production runs or in instances where other brazing processes are unfeasible due to part size or arrangement. The method’s main disadvantage is the high labor expense, as well as the operator skill necessary to produce high-quality brazed joints. To avoid oxidation, flux or self-fluxing material must be used. If copper is brazed with a torch utilizing oxygen and hydrogen gas rather than oxygen and other combustible gases, it can be done without the use of flux.
When a repetitive braze operation is required, machine torch brazing is typically used. This process combines automatic and human procedures, with an operator frequently putting brazing material, flux, and jigging pieces while a machine mechanism performs the actual brazing. This approach has the advantage of reducing the high labor and expertise requirements of manual brazing. Because there is no protective environment, this process requires the use of flux, and it is best suited to modest to medium production volumes.
Except for loading and unloading the machine, automatic torch brazing virtually eliminates the requirement for manual work in the brazing process. This process has several advantages, including a high production rate, consistent braze quality, and lower operational costs. The equipment is essentially the same as for Machine torch brazing, with the exception that the machinery does the part preparation instead of the operator.
Is MAP gas a better alternative to propane?
MAP-Pro gas burns at 3,730 degrees Fahrenheit, while propane burns at 3,600 degrees Fahrenheit. MAP-Pro gas is a superior alternative to propane for soldering since it heats copper faster and at a higher temperature.
Is brazing a better alternative to soldering?
Many people ask us what the difference is between soldering and brazing.
They are fairly comparable joining procedures in that they both involve melting a filler metal to join two or more components without melting the component’s base material.
Brazing is defined by the American Welding Society (AWS) as a method that uses a filler metal with a liquidus temperature of more than 450C (842F).
Soldering, on the other hand, necessitates the use of filler metals with a liquidus of 450C or less.
The issue is made much more complicated by the usage of phrases like “I used silver solder.”
This is a misnomer because all silver-based alloys melt well over 450C, indicating that they are brazing filler metals. The correct name for all brazing alloys, including silver-based alloys, is “filler metals for brazing.” For unique compositions of brazing filler metals, the AWS has devised a designation system that uses the principal element(s) plus a number. All identifiers begin with the letter “B,” which stands for “brazing.” BAg-x is the designation for silver-based alloys, where x is a number that corresponds to a certain alloy composition. BAg-1 is 45 percent Ag, 15 percent Cu, 16 percent Zn, and 24 percent Cd by weight. BAg-34 has a nominal composition of 38 percent Ag, 32 percent Cu, 28 percent Zn, and 2% Sn. Aluminum-silicon filler metals (BAlSi-x), magnesium filler metals (BMg-x), copper, copper-zinc, and copper-phosphorus filler metals (BCu-x, RBCuZn-x, and BCuP-x, respectively), nickel and cobalt-based filler metals (BNi-x and BCo-x, respectively), and gold-based filler metals are some of the other brazing filler metal families (BAu-x). Brazing filler metals include titanium, palladium, platinum, and other metals. Brazing can be found in a variety of places, including automobiles, jet engines, cookware and cutlery, and HVAC systems, to mention a few.
In addition to having a lower processing temperature, soldering often produces a weaker joint than brazing.
This is suitable and even desirable for many applications.
Brazed junctions often outperform soldered ones by a factor of five in shear strength.
Sensitive electronics or small components can be harmed by excessive heat.
Soldering and brazing heat can be applied in a variety of ways, including flames, resistive heating, inductive heating, laser use, combustion and subsequent radiant heating, and so on. Soldering and brazing can be done in open air or in protective atmospheres (typically with a flux to remove surface oxides and permit wetting and flow of the solder or braze filler metal) (e.g. inert, vacuum, or active atmosphere). Many metals and metallic alloys, ceramics, and composite materials, as well as like and dissimilar materials, can be joined using both processes.
The answer is dependent on a number of parameters, including the service load and the temperature, to name a couple.
The high temperatures required for brazing harm many substrates.
Another important factor to consider when choosing the right procedure is the wettability of the substrate by the solder or brazing filler metal.
Closed loop systems that cannot be easily cleaned after joining must often be brazed or soldered in vacuum or under a protective atmosphere, or a self-fluxing filler metal such as copper-phosphorus alloys (BCuP-x) must be employed in copper-based assemblies. Certain ‘no-clean fluxes’ leave little residue after joining, however hardened residues can cause abrasive wear in moving components with narrow clearances, or they can hydrolyze and cause corrosive conditions.
Is brazing as good as welding in terms of strength?
Advantages in comparison. A brazed joint is, first and foremost, a strong joint. In many circumstances, a correctly formed brazed junction (similar to a welded joint) will be as strong as or stronger than the metals being joined. Second, the joint is created at relatively low temperatures, between 1150F and 1600F (620C and 870C).
