First of all, you need to acquire the necessary tools and materials. First, you need a powerful soldering iron. Electrical – minimum of 100-watts. Even better use a soldering iron heated over an open fire. He has a large mass and keeps the required temperature. These soldering irons are now a rarity, but if you have any mass the piece of copper, attach to it a handle of wire, you can make yourself a temporary soldering iron.
The second need is solder, for example, a standard tin. And the so-called flux. Fluxes are the materials which are used for binding the oxides during soldering and welding of metals. Instead of the traditional rosin is better to use etched with hydrochloric acid – zinc chloride (ZnCl2). To zinc chloride can own. To do this, dip in a bottle with a diluted 1:1 hydrochloric acid 3-4 "pills" of zinc or more, until they cease to dissolve. In this form, zinc is supplied in the school chemistry lab. You can also use the pieces of shell used batteries. To do the described operation preferably in the fresh air. As flux use borax, pre-procalis that it is not foamed when soldering.
Preparatory work play a major and significant role. Tank, of course, must be empty, washed and dried. The leak thoroughly protected with sandpaper and degrease. From the accuracy and precision of the action will directly depend on the quality of your work. It is desirable that the tank should be removed, especially if the repair area down in the bottom. As a rule, as is often the case. Heat the soldering iron and Ludim. If there is not sufficient skill to efficiently solder the fuel tank, seek the help of a skilled neighbor.