How to Braze Steel

Clean the steel that you want to braze with either an emery cloth or steel wool. Make sure that there are no dust particles and rust on the area where you will braze the material. Wipe the area with a cotton cloth to remove other particles and make sure the metal is dry.

Mount the steel on a rotating metal table and raise it a bit using fire bricks. Raising the metal with the fire bricks is necessary to make sure heat will flow around the metal.

Mix the borax flux with water according to instructions. When the flux starts to have a paste-like consistency, dip the brush and evenly apply the flux to the metal. Apply the flux in long, straight brush strokes, covering the area where brazing is going to occur.

Turn on the compressor and light the gas torch using the pilot light or a match. Give the steel an overall heating before concentrating on the area to be brazed. This process allows the metal to expand and it also removes the excess water contained in the borax flux.

Move the torch closer to the metal and focus the flame on the area that's going to be brazed. Heat the metal in a horizontal pattern until it becomes hot enough and turns red.

Position the filler or the brazing rod (usually made of copper-zinc alloy) near the area being brazed and push it slowly and gently along the joining line; do not push too hard. Allow the filler to melt so that it can penetrate the gaps between the two metals.

Turn off the torch and allow the brazed metal to cool off on its own. Do not quench the metal because the filler will break or the metal will be distorted.