DonyRony LOGO

How to Solder Copper Pipe to Brass Fittings: Steps and Tips

How to solder copper pipe to brass fitting

Brass fittings and copper pipes are common plumbing materials, and soldering a popular way to connect them. Therefore, knowing how to solder copper pipe to brass fittings is a skill you want to master. That’s because, while the job might look simple, a few things could go wrong if not correctly done. This guide details everything that’s required when soldering copper to brass, including the dos and don’ts.

Brass vs. Copper Fittings

Before we can delve into how to solder copper pipe to brass fittings, here is what you need to know about the two types of materials: Brass is a metal, specifically an alloy, and a mix of copper and zinc. Brass fittings offer these advantages: good corrosion resistance, long life (about 2-5 times that of copper), and greater versatility. Copper fittings, on the other hand, can exceptionally resist corrosion and easily bend, but are soft and will easily wear out.

Can you Mix Brass and Copper Fittings?

You can. Despite them being made from different materials, brass and copper fittings are compatible. That being said, this is not common practice. What’s common though, is connecting copper pipe to brass fittings. Let’s see why that’s so.

Brass Fittings on Copper Pipe

Using brass fittings on copper pipe installations offers the best of both worlds: the versatility and durability of brass fittings, and the corrosion resistance and bendability of copper pipes. Plus, the two materials can be joined in many different ways. Which brings us to the question: can you solder copper to brass?

Soldering copper pipe to brass fittings
Soldering copper pipe to brass fittings

Can you Solder Copper Pipe to Brass Fittings?

You can! It’s absolutely possible to solder copper to brass. This is one of the ways of connecting the two, although other methods are available as well. Solder adheres excellently to both brass pipes and brass fittings, plus you only need a few tools for the job.

Most importantly, soldering copper pipe to brass fittings ensures a leak-free joint or connection. This makes it one of the preferred ways to install plumbing lines (whether residential or otherwise), and for both potable and non-potable water.

That being said, brass is the denser material when compared to copper. So it needs more heat than copper before the solder can melt and seep into the joint. But that doesn’t make soldering copper to brass fittings difficult. It only means you need to know how to do it correctly, as you will learn next.

Silver soldering copper pipe to brass fitting
Silver soldering copper pipe to brass fitting

How to Solder Copper Pipe to Brass Fittings

When it comes to soldering copper pipe to brass fittings, you do not only need the right tools and supplies, but also the right technique that will ensure a leak-free joint. Here, now, is how to solder brass fittings to copper pipes.

Things You’ll Need

  • Propane torch
  • An adjustable wrench
  • Emery cloth or wire brush
  • solder paste, also called soldering flux
  • solder
  • A rag
  • Brass Fittings
  • Copper pipe

Soldering Copper Pipe to Brass Fittings: Steps

Step 1: Using emery cloth or other abrasive, sand the ends of the copper pipe but on the outside. Clean, also, the interior of the brass fittings. This will help remove any material that may hinder the soldering process.

Step 2: Apply a thin layer of soldering paste (flux) to the cleaned surfaces of the copper pipe and brass fittings. Uncoil a few inches of solder and bend some length off its end.

Step 3: Assemble the joint by slipping the copper pipe inside the brass fitting. Rotate to align it in the correct position.

Step 4: Using the propane torch, heat the joint. Ensure uniform heating by moving the flame around the joint. Heat the brass fitting more. After heating the joint to the required temperature (the flux starts to sizzle), you can now solder it.

Step 6: Touch the joint with the solder. Allow it to melt and seep into the joint. Be sure also to apply enough solder.

Once through with the soldering process, allow the joint to cool. If needed, solder the other joint but not before the already soldered joint has completely cooled and solidified.

How to Solder Copper Pipe to Brass Fittings: Tips

Knowing how to solder copper pipe to brass fittings the correct way can help prevent problems. These include solder no sticking to brass because the temperature was not high enough, or a joint that has gaps and is going to leak. These tips will help you avoid mistakes when soldering copper to brass.

  • If you have to cut your copper pipe before soldering it to the brass fitting, be sure to deburr the cut end using a file and finish off with an abrasive tool such as sandpaper.
  • Never solder a dirty copper pipe to brass fittings, or the solder will not stick as it should. Clean the two first, using an abrasive tool to remove oxidation and other materials.
  • Avoid soldering brass fitting to copper pipes that still have water flowing in them. Block the flow and wipe off any water that continues to wet the pipe
  • Also, avoid applying solder onto a steaming pipe or the formed joint will be weak. Allow all steam to escape before you can begin the soldering process.
  • If your brass fitting has plastic or rubber components inside them, remove these first, or the heat of the propane torch will melt them.

Remember to always take care when using a propane torch to solder your plumbing materials. Place a heat shield to protect things that could burn behind the work area, and ensure no flammable materials are lying around near the work area. Wear protective gear, too, and have an extinguisher with you at all times


Knowing how to solder copper pipe to brass fittings is an important skill, seeing that brass fittings are one of the most common types of fittings. Soldering also forms a strong and secure joint, and suits many applications that require leak-free joints. The steps and tips in this article will help ensure the soldering process happens as it should.

Contact US

Contact Us