I was going to post more sarcasm, but, like Lawrence said, we need more info.
What grade AL are the plates?
What AL electrode were you planning to use?
What is your applicable code?
What process are you planning to use?
Have you, your welders, the company, welded AL previously?
What cleaning procedures were you intending to employ?
ETC, ETC,
He Is In Control, Have a Great Day, Brent