How You Can Sweat Copper Pipes Like A Professional

Last updated on August 20th, 2021

If you’re a DIYer and want to take on plumbing tasks, one of the essential skills you’ll need is knowing how to sweat copper pipes-also known as soldering. It’s not a difficult task, and even a newbie can master it in about 30 minutes. You only need to have some basic tools and follow some guidelines. However, the internet is filled with various guidelines with different instructions, which can be confusing. Don’t worry; we’re here for you. This article is all you need to sweat copper pipes properly.

Things You’ll Need:

When you’re soldering, you’ll need some tools as well as safety equipment to ensure that the entire process is carried out efficiently and safely. You can easily find such tools in any hardware store. You’ll need the following list of tools and equipment:

  • Insulated Gloves
  • Striker
  • Fitting brush
  • Fire extinguisher
  • Flame protector cloth
  • 120 grit emery cloth
  • Propane torch
  • Face glasses/ face shield
  • Clean rag
  • Acid/flux brush

Step By Step Guide

Step 1: Gather All Your Tools

The first thing you need to do is gather all the required tools in one place. It’s highly recommended that you keep them organized in a hardware toolbox. Make sure that you’re wearing flame protector clothes and insulated gloves at all times. Additionally, ensure that you’re wearing safety glasses/face shields when you’re soldering the pipes. This is critically important if you’re a beginner and will prevent injuries and accidents.

Step 2: Cut The Copper

Cut the copper using a tube cutter. In most cases, you’ll need a tube cutter that can cut up to 1inch tubing, which is the standard water supply line size in most houses. For larger tubing, you’ll need a hacksaw; make sure you remove all the burrs remaining from the saw teeth to prevent the joint from leaking. Use one of your hands to grip the copper tubing firmly and tuck the other end under your knee to prevent it from slipping while you rotate and tighten the copper cutter. However, don’t tighten too fast as it will dent the pipe, and you’ll have to start all over again.

Step 3: Eliminate Any Remaining Burr

Inspect the inside of all cut copper pipes to ensure that there are no burrs remaining. The burr is a ridge of copper caused by the cutting wheel where the cut was made. This allows the water to flow smoothly through the pipe.

Step 4: Clean The Mouth Of Each Pipe

Use the emery cloth to clean the cut lengths and joints of the pipes. Thorough cleaning is critical for ensuring the success of the sweating copper pipe process. This ensures that the joints are solid and leakproof. After cleaning, you shouldn’t touch the copper pipes with your bare hands or the dirt, and your skin’s natural oil will interfere with the soldering process.

Step 5: Flux The Joint

Flux has acid, so make sure that you’re wearing insulated gloves before you start working. After that, use an acid/flux brush to apply a thin and even layer of plumbing or thinning flux onto the newly cleaned areas of the interior and exterior of the copper pipes. Use a clean rag to wipe off the excess flux.

Step 6: Soldering

Wear protective glasses and clothes, fire up the propane torch and hold it about 2 inches from the joint. Pass the torch over the flux-covered areas for 10-20 seconds. The flux will soon start to melt and look shiny. The copper will become darker the flux will bubble/sizzle. Don’t be alarmed if there’s smoke; it can happen at times. This means that the acid is working. The surface will look etched and dull, making binding possible. Wear your insulated gloves and push the connecting pieces together until they’re completely sealed. Slightly twist the pipes to distribute the flux inside the joint evenly. Next, use a clean rag to wipe off the excess flux.

You must first heat the bottom of the joint. If you flame the top first, gravity will cause your solver to move downwards but will have nowhere to go since the joint’s bottom will be too cold to melt the solder. You must always start from the bottom and work your way up. Continue heating and check your solder routinely to see if it gets sucked in or not. After some time, your joint will be hot enough to accept the solder. After soldering, you must always examine the joint. If it’s not heated properly, the joint will have some voids. If this occurs, you only need to reapply the flux, flame the joint, and solder the section again.

Step 7: Clean Up

If you’re certain that the joint has been soldered properly, you just need to wait a few minutes for it to cool down.  Some plumbers prefer to use flux to clean off the joint while it’s still hot, but we don’t recommend this step as it can cause the temperature to drop rapidly, fracturing the joint and causing it to leak. After your solder has been properly solidified, wipe off any remaining flux using the rag to prevent it from destroying the pipe in the long run. After that, you’re all done.

Safety Tips

Whenever you’re not using it, make sure that the propane torch is shut off. The tank is tippy, and if you’re not careful, the torch can fall off and burn something. This can be hazardous.

Temporarily place a steel plate or hand a flame protector cloth over flammable materials such as wood if you’re soldering nearby. You must always have a bucket of water or fire extinguisher nearby whenever you’re soldering to prevent a fire from starting.


This brings us to the end of our article on how to sweat a copper pipes. It’s not a challenging task, and with the right equipment and steps, you can start soldering in no time. It’s a very useful task, and if you like tinkering around your home, it’ll prove to be very beneficial. However, always make sure that you’re practicing all safety measures when you’re soldering copper pipes.