Aluminum is generally considered difficult to weld, however, this is not entirely true. Welded aluminum is different from welded steel. This may take some practice, so here are some tips for welding aluminum.
But first, about safety
Make sure the area is well ventilated before you start welding. You don’t want to breathe in any harmful gases. Make sure you have proper protective equipment. This should include:
Welding mask to protect eyes
Gloves and leather protect you from molten metal splashes
Leather shoes or boots to protect your feet from hot metal drops
In case of long-term welding, protective masks shall be provided
There are three main types of aluminum welding:
Gas metal arc (MIG) welding
Argon tungsten arc welding
Arc welding is one of the oldest welding methods. It uses a welding power source to produce an arc to melt metal.
Not much equipment required
Working at AC or DC
It takes a lot of training and practice to master
Not applicable to thin metal
Get your equipment ready. Although both AC and DC can work, it is better to use DC.
Prepare the parts to be welded. Aluminium sheets to be welded shall be clean, dry and free of any oxidation. Heat and soften the aluminum sheets to make them easier to weld. Use a jig to place the parts on a flat surface as far as possible.
Introduce the filler rod. Hold the rod at the seam of the aluminum sheet and work on the rod with the flame more than a few inches. Moving forward is much faster than using steel, and you have to feed the rod faster. The rod will melt into a metal pool that should cover both sides of the seam.
Cooling. Allow the weld metal to cool and remove excess slag. This will give the aluminum cooling time and prevent excessive heat from accumulating in the aluminum. When aluminum is heated, the current needs to be reduced.
MIG welding was developed in the 1940s. It uses short circuits and inert gases to melt metals.
Low skill requirements
Only for thin to medium thick metals
Welds are not as clean as TIG welds
Lots of sparks, smoke and smoke
Prepare your equipment. Use a push-pull wire feeder to avoid entanglement or blockage.
Prepare your metal. Clean the aluminum, remove any oxides, and file any edges to be connected. Similarly, thicker parts are easier to weld.
Push, don’t pull. Dragging or using drag angles can cause dirty welding. For aluminum, it is better to push at an angle of 10 to 15 degrees
Practice placing beads. Using multiple straight beads can make the weld appearance more beautiful and reduce the risk of weld defects.
Use a radiator. Using radiators, such as brass, will absorb excess heat and allow you to weld slower, with similar techniques that you would for steel.
TIG welding is to wrap the electrode in inert gas.
Very clean. Low levels of sparks, smoke and smoke.
Very precise, high quality.
More expensive and time-consuming than MIG
High skill level is required.
Select your electrode. For aluminum, the best choice is pure tungsten rod.
Prepare your metal. Clean the aluminum surface with a wire brush. Preheating aluminum is also a good idea.
Control gas. Too much argon flow on the flare will cause irregular arc.
Radiator. It is also a good idea to use a radiator to prevent aluminum warping.
Welding technology. Keep the filler rod as close to the gas cloud as possible. This can be a bit tricky, so it’s a good idea to practice as much as possible in advance.