Type of aluminum welding wire to use |
Nine times out of 10 you're going to want to use a 5356 grade aluminium mig wire. The 5356 ally wire is a little bit more firmer which makes it easier to feed through your mig welding gun.
5356 is normally used for general aluminium welding tasks such as toolboxes, truck tipper bodies and trailers.
If you need to repair cast aluminum such as cylinder heads or engine water pumps you would want to use 4043 grade.
Most welding shops will use 1.2mm diameter wire which is 0.045". The larger the diameter of the wire, the more firmer that it becomes. Because ally wire is very soft it is better to use the larger diameter wire for feed ability.
Stainless steel brush
You must use a dedicated stainless steel brush for cleaning the area where you want to weld. This is because there is an oxide layer that needs to be removed. Please make sure that you do not use this brush on anything else. It must only be used on the ally. If you use it for other jobs in the shed contaminants will get into the aluminium and contaminate the weld.
Welding torch liner type
It is required that you use a teflon or plastic liner instead of the standard steel coiled liner. This will make it easier for the wire to feed through the gun.
To get more traction so that you have smooth feeding wire you will also need to get some u grooved feed rollers. Normal feed rolls are v grooved. The u shaped profile will allow for more surface area contact of the wire, thus giving it more grip to feed the wire through smoothly.
Larger contact tip
Because aluminum expands more than that of mild steel welding wire, you also need to use a slightly larger contact tip. The next size one up that is available will be ideal.
Only use the push welding technique
You need to angle your welding torch with the nozzle pointing towards the way you want to weld. By doing this the shielding gas will allow optimal coverage. If you use the pull mig welding technique you will end up having lots of black soot.
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