How To Prepare Aluminium For Welding. A great weld starts with preparation. Remove oil grease and water vapor using an organic solvent such as acetone or a mild alkaline solution like a strong soap.
Because the oxide melts at a temperature approximately 2500F 1370C higher than the aluminum itself the oxide must be cleaned from the metal before welding can begin. Aluminium surfaces need to be prepared differently to regular steel to ensure the integrity of the weld. Aluminum will start to melt at 1200deg Fahrenheit but the brazing rod will melt at around 700deg so we want to get the aluminum hot enough to melt the rod without melting the tubing.
Remove oil grease and water vapor using an organic solvent such as acetone or a mild alkaline solution like a strong soap.
Also using a brush with soft bristles is preferable to a heavy one which will likely burnish any oxide rather than removing it. Getting the tubing hot enough may take 4 to 5 minutes. Youll likely want to immerse the work pieces fully in the solution. Firstly you need to get your flux-coated aluminum electrode ready prepare the base metal set the current and polarity on the welding machine right and start welding.