I opened the package and immediately realized that things were bad. The drills I had been waiting for looked like they had been underwater for a hundred years. Rusty, dull, covered in a rough brown film. I ran my finger along one of them, and the pads turned red. “Oh well,” I said to myself, trying not to get upset. “I know how to fix this.” My new goal was to restore the drills to their former shape. Smooth and shiny, they absolutely had to be like that again. I was going to conduct the most illustrative experiment imaginable — five methods of dealing with rust. And may the best one win. First, I went online. The result was disappointing. Advice like “clean with lemon,” “dip in Coca-Cola,” or, what amused me most, “dip in carrot juice” seemed like a mockery. I was not going to waste my time on these dubious life hacks. I needed methods that actually worked. I examined the drills carefully. Rust had eaten away their surface, but the metal underneath was still alive. High-speed steel with alloying additives — tungsten, cobalt, chromium. There was still hope. These drills were made to last, and I had to save them. The first thing I decided to try was an electrochemical method — electrolysis. I took a container of water, added soda, and connected a piece of wire to the battery. The drills went into the solution. Almost immediately, gas bubbles ran across the surface. I turned on the exhaust hood just in case — let the process be safe. An hour passed. I took out the drill, and the first impression was ambiguous. The metal was clean, but covered with a black coating — magnetite. It had to be cleaned with a brush, first by hand, and then with a grinder. The drills became clean, but traces of corrosion remained on their surface. They looked better, but there was a feeling that the process could have been more delicate. Next I tried citric acid. This is chemistry. I dissolved the acid in water, added hydrogen peroxide to speed up the reaction and a drop of liquid soap. I lowered the drill into the solution. The reaction began almost instantly - bubbles, a slight hiss. I filmed it on timelapse - beautiful. After an hour and a half, I took the drill out. The result was impressive: the rust was completely gone. But the surface... It became porous, rough. The acid dissolved not only the rust, but also some metal. Clean, but aggressive. The third method is vinegar. I mixed a 9% solution with salt. Visually, the process looked like citric acid, but was slower. After two hours, I washed the drill with soda, removed the remaining rust with a brush and saw a familiar picture. Clean metal, but with signs of damage. It seemed that vinegar was a little softer than citric acid, but it still had to be treated with caution. The fourth thing I tried was a rust converter. Sold in the store, ready to use. The main component is orthophosphoric acid. I soaked the drill for an hour. After processing, the metal became dark, but smooth. The reaction turned rust into strong phosphates, which could even serve as a primer for painting. The method turned out to be gentle and suitable for delicate parts. The last thing I tested was an aerosol solvent. The product penetrated into cracks and softened the rust. But here everything depended on mechanical cleaning. Without it, the solution is simply useless. I took a vice covered with rust spots and treated it with an aerosol. In half an hour, the vice looked much better, but it was far from ideal. When all the methods were tested, I assembled the drills in a row. They stood like soldiers after a hard fight. Each one passed its test. Electrolysis pleased with its simplicity, but could not cope with large batches of parts. Acids worked quickly, but required caution. The aerosol was convenient, but weak. The rust converter showed the best balance. I decided to clean the rest of the drills with it. To enhance the effect, I used an ultrasonic bath. I heated the solution to 60 degrees and left the drills for an hour. When I took them out, they looked like they had just left the factory. Black, smooth, shiny. I carefully wiped them with an oily rag and laid them out in a box. But looking at them, I realized that simply putting them away in a box was not enough. They reminded me of old workers who had worked all their lives and then were forgotten. I decided that these tools deserved more. I took a sharpening machine. Each drill, one by one, I sharpened to perfection. First roughly - to restore the shape. Then carefully - to bring the cutting edges to a shine. When the work was finished, I again arranged the drills in a row. Shiny, sharp, they looked ready to serve again. At that moment, I remembered my grandfather. He was an engineer and had worked with tools all his life. I felt that this work was not just a restoration of drills. It was a tribute to all who once created and used these tools. I closed the box. The work was finished. But it seemed to me that this was only the beginning - there were stil