Now it’s time to flux. I’ve seen people do this two different ways and use two different kinds of flux. I really think it’s a matter of personal choice. You can do either of the following:
A. The first way I learned was using a type of flux called Battern’s. It’s light yellow in color. The flux is applied to the area to be soldered using a thin paint brush. Then the solder is placed on the metal. This way the flux and solder are heated at the same time.
B. The second way I learned was using a borax based flux that is more like a paste. The flux is again applied with a thin brush. However, instead of immediately applying the solder, the metal is heated first until the fluxed area looks like glass. Then the solder is placed on the metal.
If you need some extra time to arrange your solder, then it seems like choice B works better because it also makes the soldered area a little on the sticky side. However, it seems like an unneeded extra step because choice B requires you to heat the metal twice, while choice A allows you to flux and heat the solder at the same time.
