You’ve probably read how aluminum needs to be really cleaned thoroughly before welding.
A lot of aluminum can be tig welded without doing a whole lot of cleaning it really depends on the application.
For general fabrication, often times a wipe with acetone or alcohol will do the trick if the metal is already pretty clean like a brand new sheet with a peel coat.
But not for a welding test. Or for other critical applications.
In this video, I welded 2 butt joints…
One cleaned…and one not cleaned.
Then I tested them using a simple down n dirty test that reveals porosity in around 30 seconds.