For soldering stainless steel take an ordinary soldering iron 100 watts or more. Also you will need a special substance called flux. It is necessary to clean soldered surfaces, to get rid of oxides, improving the flow of solder and protect the places adhesions from oxidation. When soldering stainless steel as a flux for soldering is used the so-called acid – zinc chloride. You can buy in the store building materials or make your own by throwing in a solution of hydrochloric acid pieces of zinc, for example, batteries. Also you can take orthophosphoric acid. Better to solder with aluminum solder or pure tin.
Prepare the surface of the solder, and clean them from impurities with a file or sandpaper. Prepare your workplace, remember the rules of fire safety. When working with a soldering iron at hand, there should happen to be of combustible materials.
Apply the acid and solder place solder. It's not always easy, sometimes the metal rolls on the surface and does not want to spread evenly. In this case, the hot surface again and apply another layer of acid and solder again. If in the place of soldering, the oxide film appears gray, you can remove it with a stiff brush and immediately apply the acid.
When the items are tinned, solder them in the normal way. If the item is too massive to heat it entirely would be difficult. In this case, the item to be heated to flow the solder and pouring it into the place of soldering. The solder will flow to where your body temperature, so warming should be exactly the place where it needs to go numb. After soldering secure the parts with a wire for a while.
As a solder you can also use the alloy ПОС50Кд18. It contains 18% of cadmium, 50% tin and 32% lead. This solder is also convenient to solder a circuit, so they don't overheat.