Drawing with iodine

What good is the experience of drawing with iodine - everything you need for it, probably, is at home: a candle, pharmacy iodine (alcohol solution, iodine tincture) and some worthless iron object - an old door hinge, a key from an unknown lock or a lock whose keys are lost.

What good is the experience of drawing with iodine - everything you need for it, probably, is at home: a candle, pharmacy iodine (alcohol solution, iodine tincture) and some worthless iron object

The metal surface on which iodine will be painted, polish the emery cloth to a shine, light the candle and tilt it so that the paraffin drips onto the shiny surface. Lightly heat the object, then the paraffin will spread out a thin layer. And when it cools and cools, use a needle to scratch the grooves so that they reach the metal. Pipette the pharmacy iodine and drip onto the scratches. After a few minutes, the iodine solution will turn pale, and then it must be applied again to scratches. After about an hour, remove the paraffin layer: you will see clear traces on the metal, they exactly repeat the pattern on the paraffin.

If drawing iodine was successful, you can move on to a more serious lesson - not just scratch the paraffin, but write a word on it or make a drawing, for example, mark your penknife or a wrench from a bicycle.

Let's see what happens when iodine comes into contact with metal. Iron reacts with iodine, resulting in the formation of salt - iron iodide. And this salt is a powder that is easily removed from the surface. And where there were scratches, depressions formed in the metal. Such a process is called chemical etching. To it often resort, however use usually not an iodine, and other substances, more active.

By the way, iodine interacts not only with iron, but also with copper. Hence, it can be used to poison various objects from copper and copper alloys, for example, from brass. You can try.

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