How To Weld Aluminium Cracks. The crack generally is directed down into the base metal right at the weld toe. Its probably due to something called crater cracking and it happens because aluminum cools off so quickly that the puddle will sink in like a crater and this will cause a ton of stress in the weld.
The majority of aluminum base alloys can be successfully arc welded without cracking related problems however using the most appropriate filler alloy and conducting the welding operation with an appropriately developed and tested welding procedure is significant to success. This will eventually get you clean solid base metal that will form a leakproof weld. Clamp up the tubing and start heating the aluminum with a propane torch.
The majority of aluminum base alloys can be successfully arc welded without cracking related problems however using the most appropriate filler alloy and conducting the welding operation with an appropriately developed and tested welding procedure is significant to success.
Aluminium alloy must be welded with a process called TIG Tungsten Inert Gas welding. 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. Getting the tubing hot enough may take 4 to 5 minutes. Almost all the cracks in the welds at arc welding of aluminum alloys It arises due to hot cracking.