1. Ventilation
Ensure there is sufficient ventilation: brazing operations should never be undertaken in confined areas or if there is not enough ventilation.
2. Joint gap
Ensure that, at brazing temperature, the brazing joint will have the proper clearance (for “in air” brazing with flux, proper gaps range normally from 0,05 to 0,20 mm).
3. Pre-braze cleaning
Carefully and thoroughly clean the pieces to be brazed: joint surfaces must be free from any contaminant, such as oil, lubrificants, dust, grease, etc.
4. Fluxing
Apply a proper quantity of flux on the pieces in order to protect the joint surfaces from oxidation (note: when brazing copper to copper with copper-phosphorous alloys, no flux is necessary).
5. Assembly and fixturing
Assemble the pieces and ensure that they will maintain position and alignement during brazing (fixturing may be needed).
6. Heating
Heat evenly and uniformly the joint area, insisting more on heavier sections. Do not try to melt the filler alloy by directly directing the flame on the rod.
7. Brazing
As soon as the pieces reach the brazing temperature, feed the rod in the joint area and let it melt and flow. Capillary action will draw the molten alloy inside of the joint.
Avoid overheating, which might lead to damaged or deformed pieces, unsound joints, and emission of harmful fumes.
8. Post-braze cleaning
After brazing, allow the pieces to cool down and remove flux residues by washing in warm water, brushing, or other methods (chemical pickling, ultrasounds, etc.).