Solder copper

Like many other metals, copper can be soldered. One soldering process is the soldering of copper. However, you have to proceed differently depending on the individual requirements. What types of soldering copper has and what is to be considered, you will learn in the connection.

The general soldering of copper

Soldering is a typical process for joining metals and plastics. When soldering metals, a distinction is made between the following soldering techniques:

  • the soldering to a maximum of 450 degrees Celsius
  • the brazing from 450 degrees
  • high-temperature soldering between 900 and 1,200 degrees Celsius

Solder or solder copper according to the given shape

When soldering copper you also have to differentiate according to the present form of copper:

  • Solder copper wire
  • Solder copper sheet
  • Solder copper pipes

Solder copper wire

The brazing of copper wire differs significantly from the other techniques. Today, solder is preferably used, which is designed as a filler wire. That is, the solder is hollow inside and filled with flux.

After the copper wire has been prepared for soldering and the soldering iron is at the correct temperature, the soldering tip touches the wire at the location to be soldered. Directly at this point, the solder is added immediately. Experienced craftsmen and home improvement now solder in one go.

Inexperienced solderers should gradually apply some solder. It is applied as much solder until a uniformly extended soldering results. This must be slightly curved inwards like a fillet weld. In addition, the solder must shine.

If the soldered seam bulges outwards, too much solder has been used or it is a cold solder joint because the wire has not accepted the solder. Follow the link already given and get detailed instructions on soldering copper wire.

Solder copper sheet and copper pipes

Solder copper pipes

When soldering sheet metal or copper tubes, the capillary effect is used. The gap between the two sheets or between the two nested pipes must be between 0.1 and 0.2 mm. In particular, in the case of soldering copper pipes, deformations may occur, for example, due to the cutting of the copper pipes, so that the gap is no longer correct.

The appropriate gap size must be adhered to

Therefore, copper pipes must be deburred and calibrated after cutting and before brazing (even brazing copper pipes). For calibrating copper pipes, read more here. Especially in installations of building services, it must be ensured that the soldered pipes are absolutely tight. In addition, a burr inside not removed can lead to turbulence and erosion corrosion.

Not always a copper pipe may be soldered

In addition, soft soldering is not permitted in every application. This applies, for example, to gas pipes or water pipes that reach over 110 degrees Celsius. Overall, the soldering of copper pipes is demanding, because you can not see when the copper has reached the optimum temperature. To make matters worse, the good thermal conductivity of copper is added. This allows the copper to cool quickly when the heat is removed quickly.

The soft soldering of copper sheets

This is also the reason why the soldering of copper sheets is limited. The stronger the material (or one of the two workpieces to be soldered), the faster the (required) heat is removed. Therefore, even welding copper is problematic.

Tips & Tricks

Therefore, more and more often other joining techniques are used. For copper plates, it is the gluing of the copper. Advantage: the adhesive acts as a separating layer so that the copper can also be glued to other metals. With copper pipes, it is the pressing with the help of fittings, and more and more often, instead of the soldering of copper wire on pressed connections value placed. In the house installation, according to the VDE regulations, soldering is now even prohibited because solder joints are said to become porous and brittle.

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