I have to admit, that I had been
soldering about 15 years or so before I learned how to do it properly. I also have to thank South West Water for a small booklet they produced because the quality of
soldering was considered by them as poor throughout the plumbing industry region.
You will need a wet cloth and a dry cloth.
1. Clean both copper pipe and fittings with dry non-metalic cloth
2. Apply flux sparingly to male surfaces of pipe only and do not apply flux to fitting (this is especially important for gas, because excess is pushed out externally).
3. Locate pipework into fitting, twist and remove any excess flux from the fittings with a dry cloth (externally).
4. Prepare to solder, with lead free solder in one hand, and blow lamp in other - apply heat until the fitting starts to sweat. Apply solder to back or rear of fitting (if vertical) and observe as the solder runs around to the front - immediately remove solder and heat.
5. Allow to cool, and remove residual flux with wet cloth. Polish with non-metalic cloth to shiny finish.
Remember the purpose of flux is to clean and allow the solder to run,
so if you do not remove excess flux with a dry cloth before soldering, then vertical soldering is difficult because the solder runs out of the fitting and down the pipe following the flow of flux.
Follow the dry and wet cloth routine and you will have perfect joints, less risk of leaks, more money and you have conserved rare and precious metals. Not only that, you work will be beautiful and fill you with a sense of pride that money just can't buy - welcome to your vocation!
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