If you are trying to silver solder a copper joint or braze it, you have to keep in mind a few important things. Only then it will be easy for you to make it in the right order. Of course, if you are skipping any of these steps, the joint will not be proper. Joining two or more metal parts into a joint is an art.

  1. Know the Difference

It may sound that joining of two metal pieces together is “soldering”, and then what is brazing all about? So, this brazing process involves filler material as much as soldering, and the difference comes from the temperature used.

  • Soldering is done at a lower temperature for filler.
  • It is applicable for low-pressure joints like water systems and pipelines.
  • Brazing is a process that is done for HVAC systems where maximum strength of the joint is needed.
  • This is more careful and important than soldering.
  1. Tools You Need

Now that you know some difference between brazing and soldering, you would want to know the tools that are needed for the process. The brazing process is limited by its applications as well as the tools they use.

  • For soldering, you need a solder that is called 95/5.
  • This is used for potable water lines and has to be used there, but not for brazing.
  • The brazing process needs a filler material, and the right one depends on your work and application.
  • For example, Stay-slide 15 is a filler that contains 80% copper, 15% silver and 5% phosphorous.
  1. The Heat You Need

Along with the filler and solder materials we talked about before, we also have to find the right heat. Usually, the brazing process requires more heat to melt and this cannot be achieved from small propane torches.

  • You have to use larger torches with pipes more than 1 inches and up here.
  • It is better to use an oxy-acetylene torch for this kind of job.
  • This burns at around 3500 degrees Celsius which is the right heat for brazing applications.
  • They come in kits with two pipes one for controlling the oxygen, and another for acetylene.
  • They have regulators and 2 tanks for the gases and the torch.
  1. Make Sure of Flashback Arrestors

This is an important safety requirement for the torches. Most new torches come built with them mandatorily but some old ones didn’t have them.

  • Put these flashback arrestors on each tank, both on oxygen and acetylene side.
  • Earlier days they were also installed on the hoses themselves.
  • They stop the flame from going back into the tank itself that can cause an explosion
  • Also, keep safe.
  1. Coming to the Brazing Process

Some other additional safety tools are very useful but let us now talk about the brazing process and what all you need to take care of. Taking care comes because of the kind of application you are doing, such as those involving costly refrigeration units.

  • Try using an inert gas like argon to purge your lines during the brazing process.
  • Because the brazing process creates a lot of scales during oxidation, this might clog the lines.
  • Brazing on refrigeration or cooling unit is a must recommended site for this use.
  • Before proceeding, makes sure to clean your pipe and fittings well, as well as de-burr is the inside of the pipes as well using round files.
  1. Choosing Tip and Setting up Tanks

Once you have done with all the cleaning things from inside and out, you have to move to the actual brazing process itself. For that, you have to look for the right things. The first thing you will need to choose is a tip depending on the thickness of the material you are going to braze.

  • Most manufacturers specify the right tip size using a chart for it.
  • Brazing kits come disassembled and have to be set up properly.
  • First, set up the tank valves on both the tanks without any thread or sealants.
  • Purge them to see that no contaminants are going inside the torch assembly.
  • Connect now the two hoses and the torch to it.
  • Always remember how to open valves, check the pressure, and set the right flame.
  1. Which Flame Type is it?

You need to know the type of flame you are seeing so that you know which one you need and which one you do not. A wrong flame type can compromise your joint and lose its strength. It is simple to set up using the right amount of oxygen and acetylene you have mixed from the two regulators

  • A neutral flame is what we need because it does not carburize or oxidize.
  • It is a perfect mix of oxygen and acetylene.
  • Avoid an oxidizing flame or a carburizing flame.
  • The neutral flame is clean blue in color.
  1. Important Points on Brazing

Usually, when heating the pipe comes first, and the fitting later. There is a small gap of air between them and so that they both join perfectly, you need to heat them separately.

  • Heat the pipe first and make sure it reaches the brazing temperature.
  • Then start heating the fitting’s hub.
  • Keep noticing with your filler material if it is hot or not and begins to melt, this is the right temperature.
  • Don’t overheat the pipe after red hot as we want this heat to melt the filler and not the melt it directly.
  1. Proper Wetting is Always Necessary

If you do not take care of the wetting, this does not allow the capillary action to take place making it an improperly welded joint. This capillary action allows the liquid to enter narrow spaces, at times against gravity.

  • When you are filling the joint notice it does not overheat and the capillary action is working.
  • Once the melted filler is absorbed nicely, you can feel that the joint filled completely.
  • Apply a small-cap where the pipe and fitting meet each other.
  • This keeps them in place.
  1. Finishing it up

After the brazing is over, you do have to close the valves in order, apply water and purge the hoses.

  • First, close the oxygen knob slowly, then followed by acetylene.
  • Close both the tanks and their valves.
  • Purge your hoses neatly.
  • Allow brazing to cool down naturally. Do not apply water as it can cause a fracture to it.
  • Get some wire brush and remove any scaling on the surface.


  • Always open the acetylene valve first and light up the flame, next set the oxygen valve and slowly allow the oxygen to come and mix.

Make sure there are no voids in them after everything is over.

What can I use to braze copper?

The most commonly used brazing filler metal types, used to join copper tube and fittings fall into two distinct categories: BCuP Alloy (pronounced b-cup) – where the B stands for Brazing, Cu is the chemical symbol for Copper, and P is the chemical symbol for Phosphorous.

Do you need flux to braze copper?

If brazing filler metal melts, assembly is at proper temperature for brazing. Fluxing is an essential step in the brazing operation, aside from a few exceptions. You can join copper to copper without flux, by using a brazing filler metal specially formulated for the job, such as Handy & Harman’s Sil-Fos or Fos-Flo 7.

What is the difference between brazing and soldering?

We receive many questions about the difference between soldering and brazing. The American Welding Society (AWS) defines brazing as such a process which involves a filler metal which has a liquidus above 450°C (842°F). Soldering, on the other hand, involves filler metals with a liquidus of 450°C or below.

What gas is used for brazing copper?

For most brazing jobs using oxygen-acetylene gases, a carburizing or neutral flame should be used. The neutral flame has a well-defined inner cone See diagram. Avoid an oxidizing flame. Excess acetylene removes surface oxides from the copper.

Can I braze copper with a propane torch?

You can but you have to control the environment so that the heat loss to the atmosphere and parts is lower than the heat being put into the braze joint. It is a standard braze alloy that melts over a range of 1250 – 1305 F.

Is Mapp gas hot enough to braze?

Genuine MAPP gas can be used in combination with oxygen for heating, soldering, brazing and even welding because of its high flame temperature of 2925 °C (5300 °F) in oxygen.

What replaced Mapp gas?

The replacement for regular Mapp gas is called Mapp-Pro.

Is Mapp gas hot enough to silver solder?

Silver will easily melt with the heat of a MAPP gas torch, the highest temp silver solder melts at 773 degrees F. MAPP gas will melt brass. Hard soldering (silver soldering) requires temperatures of about 1200 to 1400 degrees F. MAPP should give you this kind of heat, and burns about 350 degrees hotter than propane.

Can I braze copper with MAPP gas?

MAPP gas or propane fuel get plenty hot enough for using solder. Acetylene gets even hotter so will make for an even quicker job. If you’re using really small and thin copper lines like the ones more commonly used in new construction installs you might even find acetylene is too hot and burns your lines away.

Is silver solder stronger than brazing?

Conclusion. Silver soldering offers strength comparable to other brazing metal fillers. While these joints may not be as strong as welded joints, they offer their own advantages.

Is brazing stronger than welding?

Brazing soundly beats welding when joining dissimilar metals. As long as the filler material is metallurgically compatible with both base metals and melts at a lower temperature, brazing can create strong joints with barely any alteration of the base metals’ properties.

Do you braze or solder copper?

If you have ever been involved in medical gas piping or refrigeration piping, brazing is where it’s at when joining copper tubing. On the plumbing side, we tend to solder copper tube joints when using a torch. When looking for a stronger joint, brazing is one of the options.

What solder do plumbers use?

Acid core solders are most often used in plumbing applications to join metal pipes or sheet metal. Rosin core solder is also fabricated with a hollow core inside the solder wire, but the flux used is a milder variety made of rosin, which is a solid form of resin derived from conifers such as pine.

Why must the copper fitting be cleaned before brazing it?

should be cleaned away before the part reaches the assembly point. If not removed, such materials may inhibit proper capillary attraction during heating and/or prevent the flux itself from acting directly on the metals being joined.

Can silver solder be used on copper?

A simple way of soldering together a piece of copper and a piece of silver is to use a technique called sweat soldering. Now, with a small amount of easy silver solder coated in flux and placed at the very end of some fine tweezers, you can begin to heat it with your hand torch.

How do you make copper from silver?

When a copper penny is zinc plated it will appear to change from its copper color to silver color. And by using sufficient heat, a zinc plated copper penny can be changed to gold. This version of Silver and Gold Pennies utilizes zinc sulfate as less caustic than sodium hydroxide and works as well.

What is the best solder to use on copper pipes?

Buy lead-free solder that’s designed for copper water pipes; you’ll find it in the plumbing section of the store. Solder with lead is still available, but the lead can leach into your water supply, so don’t use it.

Can I use copper wire for soldering?

As copper wiring is used so widely throughout our homes, the need to solder it may occasionally arise. Once the soldering iron has heated up enough, place the tip onto the wet sponge to ensure that it is clean. Then, holding the iron like you would a pen or pencil, apply it to the copper wire you wish to solder.