How to chose solder

1.

Select the solder composition. First choose between leaded or lead free and then between high or low temperature. Choose high temperature for easily accessible connections and low temperature for smaller, crowded connections. Next choose the alloy. Leaded solder ranges from 40 percent tin and 60 percent lead (40/60) to 50/50, 60/40 and 63/37. The first number always represents the tin content; the higher the tin content, the lower the melting point. The most common lead-free solder contains 95 percent tin and 5 percent antimony but has a melting point between that of 40/60 and 50/50 tin/lead solder. Only experience will direct you in making exact choices for your application

2.

Select the diameter of the solder wire, from between 0.01 inch (0.25 mm) to 0.125 inch (3.25 mm). You must heat the metals to melt the solder as quickly as possible. The smaller the diameter of the solder wire, the faster it will melt. But if you choose too small of a diameter, you will not get enough solder on the joint in one pass. If you choose too large, excess heat may damage your components, or you may get a solder blob.

3.

Select flux core or no core. All solder joints need flux, which can be applied from a tube, with a brush, from the core of the solder or in any combination, depending on your personal style. But you must apply flux in one manner or another. The style you develop for soldering will determine the best choice for your application, but to be safe, always use a flux core so that you don’t forget.