A simple way to solder large aluminum parts. Replacing argon welding
Soldering aluminum is not an easy task. There are fluxes and solders for soldering small parts to aluminum using a soldering iron. But to solder something larger: tubes, plates, or to reliably solder damage in an aluminum case - a soldering iron will not work.
The fact is that a thin oxide film forms on the aluminum surface, which prevents adhesion to the solder. For its destruction, fluxes are used.
There are folk methods for soldering wiring to aluminum. First: sand with fine sandpaper and cover with sunflower oil. Next, use a powerful soldering iron with tin to warm up the soldering area, carefully rubbing in the solder.
Demonstration of the process here: https://youtu.be/Jx8Astt2_vw
The second method: we make a "bath" of plasticine on aluminum, pour 1-2 ml of a saturated solution of copper sulfate in water into it. Then we connect a 12 V laboratory power supply with a current of 500 mA (minus for aluminum, and we lower the plus into the bath without touching the metal). Electrochemical deposition of copper on aluminum occurs. This spot is well tinned, can be covered with any tin solder.
Demo here: https://youtu.be/8od2WFUl0jU
It turns out that there are specially designed solders: HTS-2000 and Castolin-192 brands. The first is produced in the USA, the second in France. With their help, aluminum heated by a gas burner can be soldered like copper with tin. It is done like this:
We fix two parts and heat them up in the flame of a gas burner (a can for a gas stove with a nozzle). But not in a jet of blue flame (the temperature is too high there), but in a transparent one. Next, we touch the solder to the seam - it should melt when in contact with the details and spread.
It is also possible to close holes and cuts in aluminum. According to reviews, the solder is stronger than aluminum and never breaks at the junction. More details about this process are shown in the video:
Chinese manufacturers have also learned how to make these solders.
It is a tube made of zinc alloy (98%) with aluminum (2%) with flux inside. The diameter of the twigs is 2 mm. Length - 50 cm. Bar weight: 3.5 gr. The flux inside the bar allows reliable adhesion to the aluminum base (high adhesion) and allows the solder to flow when melted. Similar proposal on aliexpress. Also, this solder can be used to solder aluminum with copper and copper alloys, aluminum with stainless steel.
Just be careful: they sell similar products for $ 2-3. It's just aluminum wire. Or an alloy, but without a flux in the center. And without it, it will not be possible to solder reliably and quickly. The rods should look like this:
There is a Russian analogue. In Novosibirsk, the SUPER A + brand is produced. This is an analogue of HTS-2000 solder
Available in three lengths: 135mm, 210mm and 410mm. Diameter 3 mm. It melts at a temperature of 380 gr. and does not require strong heating of the adhesion points.
The process can be seen in the video: https://youtu.be/dDcToVHQE98
I watched the video. Even without flux, aluminum is confidently soldered. Why hasn't this information been met before? In 2019. When pumping the well, I had to solder the silumin cover of the Malysh-type vibration pump.
The sand has rubbed off the inlets and the body itself. Then I had to buy a new pump. And so, the solder and the gas torch would cope with the task in 5 minutes. He just drilled new holes.