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Clean and Apply Flux — Apply Flux

Beginner4 hours

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How to Solder Copper Pipes for a Permanent, Watertight Joint · Step 5 of 9

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In this video

Thoroughly clean the end of the copper pipe and the inside of the fitting using sandpaper or emery cloth until they are both bright and shiny. Once cleaned, use a brush to apply a thin, even layer of flux to both surfaces. Avoid using too much flux, as it can cause the solder to bubble out of the joint during heating.

Goal: Prepare surfaces for soldering

  • A clean surface is critical for a successful solder joint. Any dirt or oxidation will prevent the solder from adhering properly.

Used in this video

  • Sandpaper (brand: Unspecified, Tool Type: Hand Tools, Power Source: Manual)Cleaning and abrading the surfaces of the copper pipe and fitting.
  • Flux Brush (brand: Unspecified, Tool Type: Hand Tools, Power Source: Manual)Applying an even coat of flux to the copper surfaces.
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FAQs

What type of torch is best for soldering copper pipes, and how do I know I'm applying enough heat?

The K Tool International Self Igniting Propane Torch Head is sufficient for most residential copper pipe soldering. You'll know you're applying enough heat when the pipe and fitting are hot enough to melt the Oatey Safe Flo Lead-Free Solder *by touching the pipe*, not the flame. The solder should then be drawn into the joint by capillary action.

What are the critical safety precautions I must take when soldering pipes indoors?

Always have a fire extinguisher nearby and remove any flammable materials from the work area, especially when using a torch. Ensure good ventilation to disperse solder fumes, and wear safety glasses to protect your eyes from splashes or heat. It's also crucial to turn off the main water supply before starting to avoid accidents and ensure pipes are dry.

Is it really necessary to deburr, ream, and thoroughly clean the pipes before soldering?

Absolutely. Deburring and reaming with a tool like the Husky 1-5/8 in. Inner/Outer Reamer ensures a smooth pipe interior for optimal water flow and prevents solder from being blocked. Thorough cleaning with sandpaper and applying Oatey H-20 Flux are critical to remove oxidation, allowing the solder to properly bond and create a strong, watertight seal.

What are the most common reasons a soldered joint might leak, and how can I avoid them?

Leaks often occur due to insufficient cleaning, inadequate heat application, or not using enough solder. Ensure pipes are shiny clean before applying Oatey H-20 Flux, heat the joint evenly until it can melt the solder, and feed enough solder to completely fill the joint. If a joint leaks, it must be desoldered, thoroughly cleaned, and resoldered.

Transcript
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to solder on a male adapter. Make sure that you clean the fittings very well. The flux that I use, no corrode with a silver can, put it on. A little bit of flux on each fitting. Don't get too crazy with the flux, we're going to make the solder bubble out. Pop it on there, and we're going to go ahead and heat it from the bottom.

Auto-generated transcript. May contain errors.