Many people use an ordinary soldering iron and tin solder to solder brass, but this method has three significant drawbacks: a rather noticeable seam, which is also quite weak, tin during blackening can behave quite differently from brass, and then the seam will turn out a different color. Solder brass using a gas torch, special solder and flux.
It is necessary
- - gas-burner;
- - silver;
- - copper;
- - asbestos base;
- - graphite crucible;
- - borax;
- - boric acid.
Instructions
Step 1
First, make some solder. It should consist of 2 parts of silver (silver spoons can be used) and 1 part of copper. Alloy both metals with a gas burner, for this take the required amount of both metals, place them in a graphite crucible and heat it all up with a burner. After the metals have melted, stir with steel wire. The solder is ready. Now cool it down, flatten it on an anvil and cut into small pieces.
Step 2
Take borax powder (20 grams) and boric acid (also powder, about 20 grams). Stir the mixture, pour in one glass of water and boil to dissolve it better. The flux is ready. Fear not, boric acid will not harm your hands or tools.
Step 3
Now proceed directly to the soldering. Solder on heat-resistant objects, for example, an asbestos plate will do. Put the parts for soldering on it, moisten them with flux, lightly sprinkle with solder chips and start gradual heating, first the solder will grab the parts, and then heat it red-hot (about 700 degrees). The main thing here is to prevent overheating, since the difference in melting of the solder and brass parts is only 50 degrees. Also remember that small parts melt faster than larger parts, so heat slowly so that the large part heats up and the small part does not melt.
Step 4
The last step is to remove flux residues from the product. To do this, simply rinse the product in a hot 3% sulfuric acid solution. Simply tie something that won't react with acid to the garment, soak the garment in the acid for a few minutes, then rinse with running water. Please note that with this melting method, a soldering iron cannot be used, since the melting point of the solder is 700 degrees, and the soldering iron gives only 200-250.
