They use a thin plastic liner to prevent reaction with the Aluminum. These will burn off when the Al is melted for recycling. Great video here: https://www.you

They use a thin plastic liner to prevent reaction with the Aluminum. These will burn off when the Al is melted for recycling. Great video here: https://www.youtube.com/watch?v=uQHFQoFoxvQ https://www.youtube.com/watch?v=uQHFQoFoxvQ