Solder copper

In addition to electrical engineering, the soldering of copper is mainly used in installation construction, ie of pipes. In this case, different methods for soldering copper can be distinguished. Information, but also a guide to the respective soldering and bonding, you can get here.

Soldering copper for applications

Soldering is of great importance, above all with copper pipelines. Here are soldered piping systems for different transport media:

  • Water (drinking water, heating, sewage, rainwater etc.)
  • Refrigeration (gas and oil mixture)
  • Gas (natural gas, liquefied gases)
  • solar systems
  • Air (pneumatic)
  • Oils (hydraulic)

The different soldering techniques for connecting copper

When soldering copper, you can distinguish between hard soldering and soldering. Both methods focus in particular on the brazing of copper pipes. There is also the high temperature soldering (HTL), but this is rather important subordinate. The soldering reaches up to 450 degrees Celsius, the brazing 450 to about 1,150 degrees and HTL starts from about 900 degrees.

Not every soldering process allowed for each application

Depending on the transport medium and individual characteristics such as pressure (hydraulics) or temperature (heating systems, solar systems), not all soldering processes are permitted. You must therefore take into account the relevant regulations according to your installation. For gas and water installations, these would be the relevant worksheets of the German Gas and Water Association (DVGW).

The soldering of copper pipes or copper is therefore not permitted for every application. For example, heating systems may only reach maximum temperatures of up to 110 degrees Celsius.

The preparatory work

In any case, the preparation work must be carried out neatly and properly. To cut copper pipes, use the tools provided for this purpose. Then the copper pipes have to be deburred (inside and outside). Finally, the copper tubes are then calibrated.

If the pipes are not cut with suitable tools, deformations and unclean cuts can occur. The burr must be removed so that erosion corrosion can not occur (depending on the transported medium). The calibration ensures that the gap fits the capillary effect.

Instructions for soldering copper

The copper pipe is polished to the outside with a fleece metallic blank. Then the flux or the solder paste is applied. The soldering paste is not applied to the inside of the fitting. Now the copper is heated until the flux is silvery shiny. The flame is now removed and the solder moved up. It melts and immediately flows through the capillary effect into the gap.

Instructions for brazing copper

During brazing, the copper is heated to a cherry red glow. Prior to this, you must do the same preliminary work (polish, apply solder paste). Again, the flame is now turned away from the workpiece and the solder is melted along the gap. It also pulls here by the capillary effect in the gap.

Tinder during brazing

Due to the strong heating, however, scale can form on the inside of the copper tube. This must be completely removed. Otherwise, there is a weak point here in an otherwise effective piping against pitting on the copper pipe.

Tips & Tricks

In the house journal you will find many more helpful articles on copper and copper pipes. We also show you what to consider when welding copper, for example.

Video Board: How to Solder Copper Pipe The CORRECT Way | GOT2LEARN