Silver solder paste involves tiny pieces of solder already mixed with flux and a carrier to keep the flux where you put it. The melting temperature, when the paste starts to melt, is indicated by "hard" to "extra easy." The easiest is predominantly used in repair work. When the solder completely melts, it is called the flow point. The difference, or spread, between these two points determines how long you need to apply heat. Knowing how much paste solder to use requires a bit of experimenting.
Clean your work area prior to soldering for best results.
Determine the hardness of solder paste you will need. "Hard" melts at the highest temperature and "easy" melts at the lowest temperature. The temperature of your torch will determine which solder paste is necessary to use.
Clamp the two silver parts that need soldering into a vice. Position the ends of the two pieces so they are flush and have no gaps. Solder can not fill gaps but will flow around the joint to fuse them, so get a good fit for best results.
Apply the silver solder paste to the joint. You only need an amount of solder equal to the thickness of the wire or sheet you are soldering.
Light the torch and direct the flame so that both sides of the project are heated equally.
Watch the solder melt and flow to join the two pieces.
Solder can flow away from a joint before the two parts fuse if the melting point is too low for the torch temperature.
For small work, a butane torch is sufficient. You need an acetylene/air torch for larger soldering projects.
Tips and warnings
- Solder can flow away from a joint before the two parts fuse if the melting point is too low for the torch temperature.
- For small work, a butane torch is sufficient. You need an acetylene/air torch for larger soldering projects.