Soldering aluminum using conventional methods can be tricky and difficult but it can definitely be done. Aluminum has low melting temperature so its component will be less distorted in soldering as compared to brazing and welding. The process of soldering aluminum does not require the use of fluxes, rather it entails thermal spray, the typical rubbing of aluminum with solder and ultrasonic bath soldering. This process must be applied with tolerable and sufficient levels of heat on the materials to be joined together, not the solder. As mentioned earlier because of the high thermal transmission ability of aluminum, the heat source must be controlled and kept within a manageable level.
There are alternative processes in soldering aluminum like the S-Bond® bonding process. It is proven to be effective in soldering aluminum to copper, and aluminum to aluminum. It has lower temperature bonding which ranges from 120 to 250°C. The joining together of aluminum to copper, ceramics and other kinds of metals is possible as long as the heat expansion mismatch is managed. There is no need for additional metal plating on preparing the aluminum surfaces thus minimizing costs of preparation.
A new soldering technology called Ultrasonic Soldering machine is also available now on the market. It is especially designed for hard to solder metals like the aluminum, ceramic and titanium.
Soldering Aluminum Wire
Aluminum wires are soldered for electronic purposes and require the use of a soldering iron. After cleaning the area to be soldered, measure and cut off the required length. Apply resin flux to remove oxides. The resin flux is ideal for electronic soldering. Fire up the torch or soldering iron to ideal heat of at least 400 °C to make sure that necessary temperature level will be applied to melt the aluminum wire. Bind the wire around the spot to be soldered and carefully move the torch along the wire touching also the joint. Let the flux bubble up at the same making sure it does not burn. Carefully remove the solder and the tip then let the joint cool.
Soldering Aluminum Cans
Contrary to most claims that aluminum cans cannot be soldered or welded, in fact it can be done. With low heat torches, strong and sturdy welded joints can be created with no flux required. This process is even non-toxic and safe to human and the environment. Doing it is actually moderately easy; you just need a device to hold the cans initially. Heat up the soldering iron for about ten minutes or so before you touch it to the area where the aluminum solder and the cans meet. The solder melts down and holds fast to the cans. You can connect as many cans or as any project requires with this process.
Soldering Aluminum Tubing
Aluminum tubing is bendable piping that is ideal for use in structures exposed to humidity and moisture. It is usually lightweight but tough and durable. Compared to copper it has better corrosion resistance which makes it more appropriate for transferring or shifting chemicals. Aluminum tubing is also a good electrical conductor because it quickly disperses heat. Soldering aluminum tubing might require patience because of oxidation which might destroy the joints, however, with the right preparation it can be soldered to other metals with satisfactory results.
As a standard measure, clean the tubing to be soldered to remove grease and all dirt. Apply flux solution to avoid oxidation in the process of soldering. Set the temperature of the solder iron to 225 to 490 °C and set to heat up for one or two minutes. Put on protective gear before working with soldering iron, avoiding contact with its tip. Then clean off the tip with a damp sponge.
Carefully place the tip of the solder iron at the end of the wire until it melts down then remove it from the wire. Put the aluminum tubing against the metal to be soldered. To be certain of a good job, clamp the metals together. Directly make contact to the joints where the metal and the aluminum tubing meets and let stand for few seconds. Remove the tip and put the end of the solder wire to the heated joint until a slope if formed upon melting. Put away the solder wire and let cool for half a minute. Solder fumes are toxic and harmful if inhaled, always ensure your safety when working.
There is a commercially available soldering kit which can be used conveniently in more challenging soldering jobs like soldering aluminum foil.
There are also other products ideal for soldering aluminum radiators. If damage is not extensive, these soldering kits are good enough to fix your radiator. This greatly saves cost and delivers equally efficient result as compared to having a mechanic fix the job for you. But if there are any uncertainties, it is best to confer with experts to ensure safety.
Welding copper to Aluminum
Welding or soldering copper to aluminum using the ordinary method of applying heat energy might prove to be difficult and less dependable than expected. These two dissimilar metals have different melting temperatures. An effective option to weld copper to aluminum is through the use of ultrasonic energy. This wonder technology joins the metals without melting them. The process results in a very reliable weld. Ultrasonic welding of copper to aluminum has been proven to be reliable. The perennial problems of tough oxides, high electrical and thermal transmission ability, and brittle compound mixture are eliminated with the ultrasonic welding process. This modern welding equipment is proficient in controlling and keeping energy at manageable levels.
So far, there is no established fact that silver solder can be used to aluminum. Soldering and welding experts are having the same opinion that it is totally not up to standards of good soldering job. It is very efficient though to join steel, tin, copper, brass and other metals. It is also ideal for jewelry making.