There are many ways to solder a conductor to an aluminum surface, but this one is a little special. This method is chemical and consists of pre-coating aluminum with a microlayer of copper. But don’t be scared, since everything is extremely simple, and all the reagents are available to absolutely everyone.
Will need
- Ferric chloride (III) for etching boards.
- Copper sulfate.
- Salt.
- Water.
- Solder and flux. On Aliexpress with a discount - http://alii.pub/64fqb2
Tools: cotton swabs, a plastic sponge on a clothespin, a syringe, a wallpaper knife, a plastic spoon, a hard grater, a soldering iron, etc.
How to solder aluminum without special flux
Using a syringe, pour clean water into a non-metallic container, for example, a plastic disposable cup, and add copper sulfate to the water.
Close the container with a lid and shake vigorously for a while so that the copper sulfate is completely dissolved in the water.
We measure and pour 7 milliliters of an aqueous solution of copper sulfate into a glass container using a syringe, add strictly one drop of ferric chloride using a pipette and mix thoroughly with a plastic spoon.
We use an aluminum can as an aluminum surface. We remove the paint in two places spaced apart from each other on the side surface of the can using a knife.
Take a cotton swab. We soak it in a solution of copper sulfate and ferric chloride. Next, soak in salt.
Then we begin to repeatedly run a cotton swab over the cleaned surface.
In this case, a slight increase in temperature will be observed. As a result, we will remove the oxide film and prepare the surface. Finally, use a clean paper towel to remove all traces of processing.
We again moisten a fresh cotton swab in the solution, but without table salt, and rub the surface again.
We notice how a layer of copper instantly covers the aluminum surface.
We polish it with a steel grater.
OK it's all over Now. Soldering it to a copper surface is not difficult.
This method is relatively quick and simple. Does not contain scarce reagents and can be used for its intended purpose.
