How to weld aluminum parts with a soldering iron?
In the maintenance of radios and home appliances, it is sometimes necessary to weld small aluminum parts. Because the surface of aluminum devices is easily oxidized, it is difficult for beginners to weld firmly. The author referred to relevant information on aluminum welding and achieved success through experiments. This article introduces these practical methods of soldering aluminum for reference.
First, apply flux to the welding area of the aluminum parts, then dip the hot soldering iron into the tin and place it on the soldering area for preheating. When the temperature rises and the solder becomes thinner, add some flux and Solder, make the soldering iron cover the soldering iron tip, and then rub the soldering iron tip back and forth at the welding point. The friction distance should not be too large. Generally, the friction distance is between 3 and 5 mm to make the soldering iron tip scratch the aluminum oxide film on the surface of the aluminum component.
Because the welding area is covered with molten tin and is isolated from the air, it is impossible to produce a new oxide film, and the tin can promptly stick to the aluminum parts with the oxide film that has just been removed.
When the row of molten tin changes from a spherical shape to a flat shape, it indicates that the aluminum part has been firmly combined with the tin. At this time, stop rubbing and wipe off the remaining solder while it is hot, and then weld with the lead tip or other component that has been dipped in tin in advance. It's very convenient.
Second, drop a few drops of dilute hydrochloric acid on the welding joint of aluminum components to remove the surface oxide film. Wait for a while, then add a few drops of concentrated copper sulfate solution. When the welding joint is completely covered with copper, wash off the excess with water. copper sulfate solution and hydrochloric acid solution, and then use a 45-75W soldering iron to solder, and the effect is good.
Third, take a piece of aluminum and put it into a crucible to heat and melt it. Then add 2 to 5 times of tin to melt it and set it aside. It is very convenient to weld it according to the conventional method.
Fourth, apply a layer of mercury nitrate solution on the clean aluminum surface, use a 100w soldering iron tip to absorb more tin, and rub the soldering iron tip on the welding surface while applying the mercury nitrate solution. This will allow for a firm welding.
Note: Mercury is poisonous. Welding should be done in a ventilated place and do not use highly toxic mercury chloride.
Fifth, weld the aluminum parts using the local method. Prepare the white powder from sawing the fiberglass board in advance, place it on the surface of the welding joint, use a 75w soldering iron to rub the welding surface hard until a layer of tin is attached to the aluminum surface, and then use a cloth to After the mixture of white powder and rosin is removed, the general method can be used for welding. After practice, this method is simple and the welding effect is satisfactory.
You can also mix rosin and iron filings, then polish the surface of the aluminum part with sandpaper, place the rosin and iron powder on the smooth surface of the welding joint, rub it repeatedly with a soldering iron to coat the aluminum surface with a layer of tin, and then follow the normal method. Smooth welding.
Sixth, first polish the surface of the welding joint of the aluminum parts brightly, then add a few drops of sewing machine oil, the amount of oil should be sufficient, then use a sharp knife to scrape back and forth on the welding joint several times, and then use a soldering iron dipped in solder and rosin to run back and forth on the welding joint. Through friction, the tin will quickly adhere firmly to the aluminum parts. This method is also relatively simple and practical.
