Soldering to copper involves a multi-step process of cleaning, fluxing, heating, and applying solder to create a strong, leak-proof joint. Here's a breakdown of how to do it:
1. Gather Your Tools and Materials
You'll need:
- Copper pipes and fittings: Ensure they are the correct size and type for your project.
- Sandcloth or emery cloth: For cleaning the copper.
- Flux: A chemical cleaning agent that prevents oxidation during heating. Use flux specifically designed for soldering copper.
- Solder: Choose a solder appropriate for plumbing (often lead-free now).
- Propane or MAPP gas torch: To heat the copper.
- Torch striker or lighter: To ignite the torch.
- Rags: For cleaning up excess flux and wiping the joint.
- Safety glasses and gloves: To protect yourself from heat and chemicals.
2. Prepare the Copper Pipe and Fittings
- Cut the pipe: Cut the copper pipe to the desired length using a tubing cutter. This ensures a clean, square cut.
- Deburr the pipe: Use a deburring tool to remove any burrs from the inside and outside of the cut pipe. Burrs can impede water flow and weaken the joint.
- Clean the copper: Thoroughly clean the outside of the pipe and the inside of the fitting with sandcloth or emery cloth until the copper is bright and shiny. This removes oxidation and ensures a good bond. The area you clean should extend slightly beyond where the pipe inserts into the fitting.
3. Apply Flux
- Apply flux liberally: Use a brush to apply a generous, even coat of flux to the cleaned outside of the pipe and the inside of the fitting. Flux prevents oxidation during heating, allowing the solder to flow freely and bond properly. Do not touch the cleaned areas after applying flux.
4. Assemble the Joint
- Insert the pipe into the fitting: Push the pipe firmly into the fitting, twisting slightly to ensure the flux is evenly distributed.
5. Heat the Joint
- Heat the fitting evenly: Using the propane or MAPP gas torch, heat the fitting evenly around its circumference. Focus the flame primarily on the fitting, but also heat the pipe near the fitting. Avoid overheating, which can damage the copper and burn the flux. The goal is to heat the metal, not melt the solder with the flame directly.
- Check for proper temperature: The fitting is hot enough when the flux starts to bubble and turn clear.
6. Apply the Solder
- Touch the solder to the joint: Touch the solder wire to the joint where the pipe enters the fitting. If the fitting is hot enough, the solder will melt and be drawn into the joint by capillary action. Apply solder around the entire circumference of the joint.
- Avoid overheating: Do not apply too much solder or overheat the joint. Overheating can cause the solder to run and create a weak joint.
- Use enough solder: Apply enough solder to fill the gap between the pipe and fitting completely. A properly soldered joint will have a smooth, shiny fillet of solder around the entire circumference.
7. Cool and Clean the Joint
- Remove the heat: Once you've applied sufficient solder, remove the torch.
- Allow the joint to cool: Allow the joint to cool naturally. Do not quench it with water, as this can weaken the joint.
- Wipe off excess flux: While the joint is still warm, wipe off any excess flux with a damp rag. This helps prevent corrosion.
8. Test the Joint
- Pressure test: After the joint has cooled completely, pressure test the connection to ensure there are no leaks.
By following these steps carefully, you can create strong, leak-proof soldered copper joints.
