Platinum welding techniques
Use of the oxy-hydrogen torch and porosity management.
Platinum welding is one of the most demanding techniques in jewelry. It requires a specific workshop environment and advanced training.
Working Temperature: Commercial platinum solder (platinum welding wires) melts between 1,400 and 1,600°C — well above those used for gold (600–900°C). The heat source must exceed 1,700°C locally.
Heat Sources: Oxy-hydrogen torch (produces a near-clean flame without carbon contamination, ideal). Oxy-acetylene torch (hotter but use with caution — carbon from acetylene can contaminate platinum). Welding laser (maximum precision, no global overheating risk — recommended for prong settings).
Risk of Porosity: If the metal absorbs gases (oxygen, nitrogen) during welding, the piece ends up with micro-bubbles that weaken the joint. Working under argon flow (protective gas) or using commercial platinum melting fluxes eliminates this problem.
Post-welding Cleaning: Soaking in diluted hydrochloric acid (10% HCl) to dissolve surface oxides. Abundant rinsing with distilled water. Never use sulfuric acid (H₂SO₄) — it does not attack platinum but can contaminate present rhodium or iridium alloys.