If you need to fix a leaking pipe you can do it yourself, saving money, and as long as you have everything you need. Learn to solder copper pipes using things you can easily buy in specialty stores or large shopping centers like Brico.
Steps
Part 1 of 2: Getting the Materials You Need
Step 1. Find copper pipes of the right diameter
The copper ones used for the pipes have a real diameter larger than the declared one, i.e. the difference between internal and external diameter. In other words, a 14mm tube measures 17mm.
If you have to cut the pipe, do it correctly: tighten it firmly with pliers and use a cutter while rotating the pipe. Usually 8 rounds are enough
Step 2. Make sure the tube is the right thickness
Most of the tubes are available in different thicknesses, generally from 12 to 22 mm. They are also denoted by letters such as L or M.
Type L ones are marked with a blue label and are the most used in commercial and residential installations. Type M pipes have a red label and are those with the least thickness that can be used in pressurized systems
Step 3. Get the appropriate sleeves and fittings for the system you are building
Depending on what you are doing you will probably need:
- Male / female adapters, used to join welding tubes with threaded tubes.
- Reducers, to join pipes of different sizes, from largest to smallest.
- Elbow fittings, used to make corners. Generally, those bent at 90 ° are used but there are also at 45 °.
- Tee fittings, those used to connect pipes forming a "cross".
Step 4. Choose a league
Lead-free alloys must be used for potable water systems. They are usually 95/5 (95% tin and 5% antimony), or an alloy of tin and a small part of silver. Leaded alloys should not be used for drinking water.
Step 5. Find the suitable solder flux
This is usually a zinc chloride gelatin or rosin that is used to cover the surface of the copper to be soldered prior to assembly and heating. The function of the flux before heating is to contribute to further cleaning by excluding oxygen in order to prevent new oxidation, and to help wet the weld.
Step 6. Get a heat source
A normal electric soldering iron will not be sufficient to work with copper pipes. Much more heat is needed to work with similar materials, a source that reaches temperatures between 200 ° and 300 ° C. For this it is better to use oxyhydrogen flames of the right size fueled with propane or acetylene gas. Also take some clean cotton cloths and a sprayer full of water and you will have everything you need.
Part 2 of 2: The Welding
Step 1. Prepare the tube
Remove the copper oxide coating both on the outside where it will be inserted into the fitting, and on the inside of the fitting itself. To do this, you can use sandpaper, abrasive cloth or other special products that are sold in stores. All copper oxide must be removed until the surfaces are perfectly clean, without deposits, oil, grease and other things that can hinder the welding. If you don't, you will get an unstable fitting and leaks.
A drop of water in the part to be welded is enough to ruin the process and result in leaking pipes. The system valves must be completely closed and there is no water before starting work
Step 2. Brush clean surfaces with solder flux as soon as possible after cleaning and assembling the pipe and fitting
Step 3. Turn on the flame and adjust it until you have a blue flame
Move it to the joint between the pipe and the fitting by moving it to the parts where you are going to put the tin. Heat the area slowly and evenly, in a steady motion and at the same time check the melting point of the alloy by touching the joint with the tin wire.
This will take some practice. Hold the alloy with your main hand and the blowtorch with the other and remember that you are only using the flame to heat the alloy and melt it, so use it sparingly
Step 4. Melt the alloy in the joint
Move the alloy and flame away from the molten alloy while continuing to add small pieces of alloy and moving the flame until you have made a turn around the fitting.
- You will feel like you see the alloy moving towards heat. The aim is to make the alloy melt by completely covering the area between the pipe and the fitting, also covering the gaps. If you work on larger fittings, concentrate the heat slightly ahead of the wet weld to allow for this.
- Be careful not to overheat the copper. Always move the flame to avoid blackening it: an overheated and blackened joint will need to be disassembled and cleaned or is likely to cause leaks.
Step 5. Remove excess liquid alloy with a clean, dry cotton cloth
Spray some water where you worked to cool the alloy and prevent any movement in the joint that could lead to leaks.
Step 6. Wash the pipes thoroughly
Use water to remove any flux residue, dirt or solder residue left inside the pipe. This way you can also check that there are no leaks.
Advice
- When welding, there must be no positive pressure inside the system especially in the final joint. Bubbles that form due to expanding gases inside the heated tube can cause leaks. Remember to ventilate the system before welding.
- Most problems arise when you do not thoroughly clean the surface of the pipe and the inside of the fitting and not cover the parts well with flux after cleaning.
Warnings
- When using a blowtorch, a fire is always a danger. Remember to keep a fire extinguisher handy before turning on the flashlight.
- Pay close attention to the tin drops. Always wear warm clothes, protective gloves, and goggles (you could be blind if you get caught in your eyes).
