How to Make Solder Paste
- 1). Determine proper metal load composition. Metal load is the ratio between the metal solder powder and the flux agent. The greater the solder strength needed, the greater the metal ratio will be. A 50-50 mix will provide optimum strength.
- 2). Choose the type of flux agent to be used. A rosin-based flux is soft, noncorrosive and ideal for electrical applications. Stronger flux agents, made from acids and salts, produce stronger soldered joints but are more corrosive.
- 3). Pour predetermined amounts of filler metal powder and selected flux agent into portable paste mixer. Operate according to manufacturer's instructions. If you do not have a mixer, you may mix by hand. The paste may be used within fifteen minutes after completion.
- 4). Place unused solder paste in your choice of airtight container, nonmedical syringe or cartridge made for solder paste. Paste may be stored in refrigerator for up to two years or at room temperature for up to six months. It must be at room temperature before using.