Re-heat and Apply Additional Solder — Apply Solder
Part of project
How to Solder Copper Pipes for a Permanent, Watertight Joint · Step 8 of 10
In this video
Apply flux to the tip of your solder wire. Use the torch to heat the entire joint, moving the flame back and forth over the fitting. Once the pipe is hot enough that the existing solder becomes shiny and molten, touch the fluxed solder to the joint opposite the flame. The heat from the pipe will melt the solder and draw it into the joint, sealing the leak. Apply solder around the entire circumference of the joint to ensure a complete seal.
Goal: Repairing leaking plumbing pipes
- Heat the fitting more than the pipe, as it is thicker and requires more heat to reach the correct temperature.
- Solder follows heat. Direct the flame to the area where you want the solder to flow.
Used in this video
- Propane Torch — To heat the copper pipe joint.
613K subscribers
FAQs
What are the most critical safety precautions I need to take when soldering copper pipes?
Always wear safety glasses and gloves to protect from heat and flux. Ensure adequate ventilation, keep a fire extinguisher or bucket of water nearby, and use a heat shield (like the Oatey 9 in. x 12 in. Hands-Free Solder Heat Shield) to protect surrounding flammable materials from the torch flame and hot pipes.
Why is cleaning and deburring the pipe and fitting so crucial before applying flux and soldering?
Thorough cleaning with a fitting brush and sandpaper removes oxides and contaminants, which are essential for the solder to properly flow and adhere via capillary action. Deburring with a tool like the Husky 1-5/8 in. Inner/Outer Reamer ensures the fitting seats correctly and prevents turbulence in water flow, promoting a perfect solder joint.
How do I know I'm using enough solder, and what commonly causes a joint to leak after soldering?
You've used enough solder when you see a complete, continuous ring of solder around the joint's circumference, indicating full capillary fill. Leaks are often caused by insufficient or uneven heat application, improperly cleaned surfaces, or applying too little solder, which results in an incomplete or 'cold' joint.
Can I use a regular propane torch, or do I need a MAPP gas torch for soldering copper pipes?
While a basic propane torch might suffice for smaller pipes (1/2" - 3/4"), a MAPP gas torch (such as the Flame King High Intensity Propane Torch Head) provides a hotter flame. This is more efficient for larger pipes and quicker heating, reducing the risk of overheating the pipe or burning off the flux prematurely, which are common beginner mistakes.
Re-heat and Apply Additional Solder — Apply Solder
Part of project
How to Solder Copper Pipes for a Permanent, Watertight Joint · Step 8 of 10
In this video
Apply flux to the tip of your solder wire. Use the torch to heat the entire joint, moving the flame back and forth over the fitting. Once the pipe is hot enough that the existing solder becomes shiny and molten, touch the fluxed solder to the joint opposite the flame. The heat from the pipe will melt the solder and draw it into the joint, sealing the leak. Apply solder around the entire circumference of the joint to ensure a complete seal.
Goal: Repairing leaking plumbing pipes
- Heat the fitting more than the pipe, as it is thicker and requires more heat to reach the correct temperature.
- Solder follows heat. Direct the flame to the area where you want the solder to flow.
Used in this video
- Propane Torch — To heat the copper pipe joint.
Frequently Asked Questions
What are the most critical safety precautions I need to take when soldering copper pipes?
Always wear safety glasses and gloves to protect from heat and flux. Ensure adequate ventilation, keep a fire extinguisher or bucket of water nearby, and use a heat shield (like the Oatey 9 in. x 12 in. Hands-Free Solder Heat Shield) to protect surrounding flammable materials from the torch flame and hot pipes.
Why is cleaning and deburring the pipe and fitting so crucial before applying flux and soldering?
Thorough cleaning with a fitting brush and sandpaper removes oxides and contaminants, which are essential for the solder to properly flow and adhere via capillary action. Deburring with a tool like the Husky 1-5/8 in. Inner/Outer Reamer ensures the fitting seats correctly and prevents turbulence in water flow, promoting a perfect solder joint.
How do I know I'm using enough solder, and what commonly causes a joint to leak after soldering?
You've used enough solder when you see a complete, continuous ring of solder around the joint's circumference, indicating full capillary fill. Leaks are often caused by insufficient or uneven heat application, improperly cleaned surfaces, or applying too little solder, which results in an incomplete or 'cold' joint.
Can I use a regular propane torch, or do I need a MAPP gas torch for soldering copper pipes?
While a basic propane torch might suffice for smaller pipes (1/2" - 3/4"), a MAPP gas torch (such as the Flame King High Intensity Propane Torch Head) provides a hotter flame. This is more efficient for larger pipes and quicker heating, reducing the risk of overheating the pipe or burning off the flux prematurely, which are common beginner mistakes.