How to braze the aluminum wiring?

  • Dec 26, 2019

In implementing the power wiring in the house it is preferable to use copper wires. However, under severe budget constraints we have to deal with power cables with aluminum conductors.

When connecting individual segments of such cables the best way to achieve the desired quality - reduction of the contact resistance by soldering.

Why it is difficult to solder aluminum wire?

In contrast to the copper wires of aluminum brazing living it is not so simple. This feature is due to the following factors:

  • quite high chemical activity aluminum, resulting in a buffed surface instantly formed solid oxide film of small thickness;
  • markedly smaller as compared with copper aluminum melting temperature that does not give a good warm mating wire without risk of plastic deformation;
  • Alloys based on bismuth, tin and other fusible metals without special measures are reluctant to interact with aluminum and do not allow to obtain the desired density of the clutch.

These difficulties can be overcome by choosing appropriate technology and the use of special fluxes.

preparations

Before soldering aluminum wire:

  • carefully purified from dirt;
  • cleaned with a wire brush or a file, followed by treatment with a special flux for aluminum brazing, which destroys the oxide layer.

Quite often, two additional reception employed, increasing the quality of the compound:

  • adding a flux fine abrasive (suitable conventional sand), which contributes to further destruction of the oxide film (A similar effect is achieved if the cover rosin wire soldering tip to press it to a fine emery cloth and drag wire under sting);
  • obluzhivanie place tin solder contact (thin film formed after its solidification, prevents oxidation).

Actually solder can perform a soldering iron or torch.

Work with a soldering iron

When the wires of 1 mm diameter solder must have the capacity of 100 watts, the 50-watt tool is only suitable for thinner wires. A better joint is obtained by selecting the temperature of the soldering tip via the power regulator.

Tinned wires tightly pressed or twisted with each other as shown in Figure 1. Additionally, once applied flux and brazed together by applying the required volume of solder in the contact region.

Picture 1. Brazing aluminum conductors soldering iron
Picture 1. Brazing aluminum conductors soldering iron

Brazing gas burner

For manual operation it is advisable to use a gas burner, an embodiment of which is shown in Figure 2. Before starting the work it is necessary to adjust so that the flame was smooth without soot.

Figure 2. Manual gas burner for brazing aluminum wire
Figure 2. Manual gas burner for brazing aluminum wire

Pretreated wire tightly pressed together and heated burner. Place the joint "rub" rod of solder so as to achieve his first tinning and then soldering. At work, a special solder for aluminum wires.

finishing procedures

After soldering the first control:

  • completeness filling solder joint area (example of quality of soldering is shown in Figure 3);
  • mechanical strength and the absence of the so-called cold solder connection point, which is simple enough to try to stretch the wire.
Figure 3. EXAMPLE quality soldering of aluminum wires
Figure 3. EXAMPLE quality soldering of aluminum wires

To impart the desired appearance of the abutment can be smoothed out with a file or sandpaper. Thereafter applied insulation.

conclusion

Even at home, subject to certain simple rules it is possible to solder aluminum wire, thereby improving, the connection parameters for the transition resistance and durability.

This will require only a simple technological tools and supplies, as well as compliance with certain accuracy.

An additional positive aspect of the development of solder wire is that the same technology also makes it possible to solder other aluminum products.